• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    stable submarine electric power transmission to operate high-speed submarine engines. the present invention provides a submarine pressure boosting system achievable for operation in submarine clearance lengths over 40 km and by control merely from a dry top or onshore location. in accordance with the present invention, the system is distinctive in that it comprises: at least one subsea power spacing cable, disposed from a nearby end in an onshore location or dry tops for one or more subsea loads such as subsea pumps or subsea compressors or other loads at a distant end, at the close end at least one source of electrical power is connected and the cable is sized for operation at a different frequency from the operating frequency of the subsea loads connected in order to manipulate the ferranti effect and electrical losses; and at least one passive electrical frequency transformer, operatively connected between the distant end of the subsea spacing cable and the subsea loads, said transformer being located in a pressure vessel and transforming the frequency of operation of the subsea spacing cable to a realizable frequency for operation of connected loads.
    公开号:BR112013005951B1
    申请号:R112013005951-6
    申请日:2011-09-13
    公开日:2020-03-24
    发明作者:Kjell Olav Stinessen；Ole Johan Bjerknes
    申请人:Aker Solutions As；
    IPC主号:
    专利说明:

    “SUBMARINE PRESSURE LIFTING SYSTEM, PASSIVE ELECTRIC FREQUENCY LIFTING TRANSFORMER AND METHOD FOR OPERATING A SUBMARINE PRESSURE LIFTING SYSTEM
    TECHNICAL FIELD OF THE PRESENT INVENTION [001] The present invention relates to subsea technology, particularly subsea technology for oil production. More specifically, the present invention relates to systems, equipment and methods applied for oil production or operation of related subsea equipment. The present invention is more relevant for equipment requiring high transmission of alternating current energy over long subsea distances, through a long subsea cable, such as motors for pumps and compressors that typically require rotational speed control by controlling the electrical frequency. .
    [002] The present invention comes to be confronted with the problems caused by the Ferranti effect and the skin effect, thereby giving opening to submarine distances longer than previously obtained. DESCRIPTION OF THE STATE OF THE TECHNIQUE [003] Over the past few decades, global energy consumption has increased exponentially and no end can be seen for increased demand. While fossil fuel exploration was previously focused on onshore fields, the limited amount of oil initiated serious efforts to find and explore offshore oil and gas fields.
    Petition 870190111975, of 11/01/2019, p. 7/62
    2/51
    At present, the state of the art for production from offshore fields is through the use of fixed or floating manned platforms, and by combining subsea production models with subsea wells for those platforms. In some cases, it is routed directly to an onshore reception facility without a platform. In order to maintain a sufficiently high production from underwater satellites to a central platform or directly to the coast, elevation of pressure can be provided by using a multiple phase pump or by separation followed by pumping and compression. Pumps were also installed in sea beds to direct injection of sea water into the reservoir for pressure support for reinforced oil production.
    [004] There are several advantages that motivate the underwater location of pump and compressor stations compared to location on platforms:
    • Personal security for not working and living on a platform and not being transported by helicopters to and from there.
    • No risk of fire and explosion.
    • No risk of overflow from production risers from the seabed to the platform and from the platform to the seabed.
    • Security against sabotage.
    • Cost savings for both capital and operation, that is, cost of
    Petition 870190111975, of 11/01/2019, p. 8/62
    3/51 reduced production for oil and gas.
    • Increased production due to the fact that the suction effect of compressors and pumps is closer to the wellheads.
    • The equipment has stable ambient conditions, that is, almost constant, cold and almost constant temperature, low flow water flow speed around the equipment and no waves, while the temperature on the platforms can vary from, for example, -20 ° C to + 30 ° C and the wind speed can be in hurricane strength combined with extremely high waves.
    • The cold seabed can be used to cool motors and other electrical and electronic equipment and process fluids.
    • No visual pollution.
    • Considerably lower weight and, as a result, less material and less energy to manufacture an underwater plant.
    • Lower carbon dioxide, that is, emission of harmful gases for manufacturing due to the fact that there is less material.
    • Less carbon dioxide emissions during operation due to the elimination of helicopter transport and platform operation.
    • Less emission of carbon monoxide compared to platforms due to the fact that electric motors to operate compressors and pumps and electricity supply from the
    Petition 870190111975, of 11/01/2019, p. 9/62
    4/51 coast or platform.
    • Less energy consumption and emission of climatic gas per unit weight of oil and gas.
    [001] The disadvantage for submarine compressors around 2010 is that none was installed and operated submarine, that is, the technology was not put to the test. However, this is only a matter of time, and the first subsea compressor station is likely to be in operation in 2015 or earlier due to the strong motivation for this application.
    [002] Underwater pressure elevation is a recent technology. Raising underwater pressure requiring a significant underwater distance is a very recent technology using modern equipment and facing problems that are not found or that is irrelevant elsewhere.
    [003] The state of the art technology is defined in publication WO 2009/015670 prescribing the use of a first converter arrangement at the near end, the upper parts or onshore end, of a submarine cable and a second converter arrangement at the far end, the remote submarine end of the submarine cable. A variable speed pull, VSD, is prescribed at either end of the cable. Submarine variable speed drives (VSD) for electric motors are also called variable frequency drive (VSD) and frequency converters or converters only and they represent
    Petition 870190111975, of 11/01/2019, p. 10/62
    5/51 state of the art technology. Neither in the patent application WO 2009/015670 or in other publications is the Ferranti effect mentioned, nor are any problems associated with VSDs discussed or indicated.
    [004] So far only a few subsea pumps and no subsea compressors are in operation. Submarine compression stations are, however, being developed and the first expected to be installed and start operating should be within a few years. These days, underwater pumps and underwater compressors are all powered by asynchronous engines. The distance of installed pumps is more than about 30 km from the platform or coast and so far the depths are not below 1,800 m. It is known that studies and serious projects are conducted by the oil industry aiming at installing compressors over a distance in the range of 40 km to 150 km and in water depth descending to 3,000 m or more.
    [005] Realistic motor energy is from around 200 kW for small pumps and above 15 MW for compressors, and in the future even bigger engines can be predicted. Submarine engines that are currently installed are supplied with power through alternating current cables from the location of the power supply, that is, platform or coast, and in the case of several engines, each engine has its own cable and frequency converter (Variable Speed Drive - Variable Speed Drive
    Petition 870190111975, of 11/01/2019, p. 11/62
    6/51
    VSD, sometimes called Adjustable Speed Drives - Adjustable Speed Drives ASD or Variable Frequency Drive - VFD) at the end of the cable in order to control the speed of each individual motor at the far end of the cable, see references to Figure 1 and Table 2.
    [006] In the context of this specification, close end means the end of the power transmission close to the power supply. In subsea applications, this is the location or onshore of upper parts platform. Correspondingly, the far end refers to the other end of the transmission line next to the power loads, typically engine loads. Distant end is not necessarily restricted to the high voltage end of the transmission line. The expression can be extended to lower voltage buses or terminals that are part of the far end station, such as, for example, a common submarine bus over the low voltage side of a submarine transformer.
    [007] Compressors and pumps are often operated at maximum speeds between 4,000 rpm to 14,000 rpm and 2,000 rpm to 5,000 rpm, respectively. Consequently, the electric traction motor must have a speed in the range of 2,000 rpm to 14,000 rpm when using modern high-speed engines without a gearbox between the engine and the pump or compressor. This speed
    Petition 870190111975, of 11/01/2019, p. 12/62
    7/51 mechanical corresponds to an electrical frequency range for the feed traction of about 30 Hz to 230 Hz for the example of a two-pole motor. Engines with more pole pairs should allow lower maximum mechanical speed for the same electrical frequencies.
    [008] Figure 1 illustrates the only solution used so far for transmitting electric energy to installed pumps. In some cases without transformers between the VSD and submarine engines, this is referred to as the First Solution. This solution, with a motor transmission cable, has the disadvantage of being expensive for long distances, for example, of more than 50 km, due to the high cost of cable.
    [009] A serious technical obstacle against this solution is that at a given underwater distance, the transmission of electrical energy from a power source close to a distant engine from a distant end is not suitable due to the fact that the transmission system will become electrically unstable and inoperable due to the fact that the Ferranti effect will be described later. The present invention will solve this problem of instability.
    [0010] Figure 2 illustrates an solution what is it proposal for transmission in energy electrical for various loads in long Clearances, Solution Two. This solution common
    common transmission cable and subsea power distribution system including a VSD
    Petition 870190111975, of 11/01/2019, p. 13/62
    8/51 submarine per engine will considerably reduce the cost of transmission cable, and also prevent the problem of electrical instability by limiting the frequency of the current in the transmission cable, that is, 50 Hz - 10 Hz, and the skin effect it is also acceptable for such frequencies. The frequency is then increased by a VSD to match the speed of the connected motor to the VSD. However, the Second Solution also has disadvantages. These are expensive VSDs, which have not been proven for underwater use, and due to the fact that such VSDs are composed of many electrical and electronic components included in a control system, they are likely to contribute to an increased transmission failure rate. electrical and subsea distribution system.
    [0011] The following will describe the electrical problems inherent in the existing First Solution (Figure 1), with a motor at the far end of a long cable, and a Third Solution illustrated in Figure 3 with several motors at the far end of a long cable. common transmission and a common VSD at the near end.
    [0012] For a long distance from the power supply for the load, in the order of 50 km, and above, the influence of the submarine cable is so strong that such a system has not yet been built for a limited load such as an engine single. Inductance and line resistance involve a large voltage drop from the power supply to the load. It is known that such a voltage drop is amplification in itself
    Petition 870190111975, of 11/01/2019, p. 14/62
    9/51 and can result in zero voltage at the far end. The longer the distance, the higher the voltage transmission must be in order to reduce the voltage drop along the transmission line. However, a cable has a high capacitance and a long alternating current cable will exhibit a significant Ferranti effect. The Ferranti effect is a known phenomenon where the capacitive charging current of the line or cable increases with the line length and the voltage level. At a distance of 100 km the charging current on a cable can be higher than the charging current, which makes it difficult to justify such an inefficient (ineffective) transmission system. A more critical result is that the unloaded voltage will be about 50% higher than the near-end supply.
    [0013] Voltage that should destroy the cable and the transformer and distant end connections. In a sudden load drop, the far end voltage will jump to this high level. In addition, there will be a transient peak of, for example, 50% determining something like 100% in total, see Table 1 below, where values marked with bold italic letters are above the insulation voltage class range.
    [0014] Today's systems with distances of the order of 30 km do not present this problem, due to the fact that the underwater distance and electric charge in combination is still adequate.
    Table 1: Elevation of tension in load shifts due to the fact of the Ferranti effect in
    Petition 870190111975, of 11/01/2019, p. 15/62
    10/51 different systems.
    Far end shaft energy Transmission frequency (f max ) and motor speed (ω max ), maximum Distance Standard cable Source voltage at near end (U) Full load and no load voltage (U) Peak Far Transient Voltage (Up) Aftertotal load displacement bomb2.5 MWFirstSolution 60 Hz(3,600 rpm) 4 0 km 95 mm 2 30 (36) kV 2 0 kV 18.3 kV20.2 kV 20.9 kV Compressor7.5 MWFirstSolution 180 Hz(10,800 rpm) 4 0 km 150 mm 2 30 (36) kV 32 kV 29.2 kV34.8 kV 41.0 kV bomb2.5 MWFirstSolution 60 Hz(3,600 rpm) 100 km 150 mm 2 30 (36) kV 2 6 kV 23.6 kV27.5 kV 28.9 kV 7.5 MW Compressor First Solution 180 Hz(10,800 rpm) 100 km 150 mm 2 30 (36) kV 28.5 kV 28.8 kV52.7 kV 68.4 kV
    Petition 870190111975, of 11/01/2019, p. 16/62
    11/51
    Three 180 Hz 100 km 400 mm 2 45.6 kV 45.6 kV 155 kV compressors Compressor:45 (54) kVunstableit's three 10,800 rpmbombs Bomb:Total: 30 MW 5,400 rpmThird Solution
    The Ferranti effect and the skin effect - some considerations:
    [0015] The Ferranti effect is an increase in voltage occurring at the far end of a long transmission line, relative to the voltage at the near end, which occurs when the line is loaded, but there is a very light load or the load is disconnected. This effect is due to the fact that the voltage drop through the line inductance (due to the fact of the charging current) is in phase with the sent end voltages. Consequently, both capacitance and inductance are responsible for producing this phenomenon. The Ferranti effect will be more pronounced the longer the line and the higher the applied voltage. The relative voltage rise is proportional to the square of the line length.
    [0016] Due to the fact of the high capacitance, the Ferranti effect is much more pronounced in underground and submarine cables, even in short lengths, compared to transmission lines suspended in the air.
    [0017] A proposed equation to determine the Ferranti effect for a given
    Petition 870190111975, of 11/01/2019, p. 17/62
    12/51 system is:
    Vf = Vn (1 + ω x C x L x | 2 )
    Where:
    Vf = distant end voltage;
    Vn = near-end tension;
    ω = 2 x 3.14 x f;
    f = frequency;
    C = line capacitance;
    L = line inductance;
    | = line length; and | 2 = line length square.
    [0018] In the literature, other expressions can also be found for the Ferranti effect, but in any case it is agreed that the effect of increases with transmission frequency, cable capacitance, cable length and voltage.
    [0019] From the equation mentioned above, it can be concluded that the Ferranti effect of a long line can be compensated for by an adequate reduction of the electrical frequency. This is the reason for the Second Solution with underwater VSD. The transmission frequency can, for example, be the normal European frequency of 50 Hz.
    [0020] Another benefit with low frequency transmission is that it significantly reduces the electrical skin effect of the transmission cable, that is, better use of the cross-sectional area of the cable. In practice, transmission of high frequency electricity, for example, from
    100 Hz or more over long distances, for example, 100 km or more, will become prohibitive due to the skin effect and the
    Petition 870190111975, of 11/01/2019, p. 18/62
    13/51 corresponding high resistance of the cable.
    [0021] The influence of the Ferranti effect and the skin effect must obviously be calculated from case to case to assess whether they are acceptable or not for transmission at a certain frequency. A demand exists for the provision of subsea electricity transmission systems that are beneficial with respect to the problems mentioned above.
    BRIEF DESCRIPTION OF THE DRAWINGS OF THE PRESENT INVENTION [0022] The present invention is illustrated by the figures, in which:
    Figures 1 - 3 illustrate state of the art modalities; and
    Figures 4 - 8 illustrate embodiments of the present invention.
    SUMMARY OF THE PRESENT INVENTION [0023] The present invention provides a subsea pressure elevation system suitable for operation at subsea distances above 40 km and for control merely from a dry top or onshore location. The system is distinctive in that said system comprises:
    - at least one subsea power cable, disposed from a nearby end at an onshore location or dry tops for one or more subsea loads such as subsea pumps or subsea compressors or other charges at a distant end, at least near the end a power source is connected and the cable is sized for operation at a frequency
    Petition 870190111975, of 11/01/2019, p. 19/62
    14/51 different from the frequency of operation of the underwater loads connected in order to manipulate the Ferranti effect and electrical losses; and
    - at least one passive electrical frequency transformer, operably connected between the distant end of the submarine cable and the underwater loads, said transformer being located in a pressure vessel and transforming the operating frequency of the submarine cable to a frequency suitable for operation of the loads connected.
    [0024] In none of the previous submarine pressure lifting systems, the Ferranti effect was taken into account. The preceding system version with an underwater VSD can therefore be useless for many applications, as the cable insulation can be damaged by uncontrollable high voltage at the far end due to the fact of the Ferranti effect. The characteristic of a “passive electrical frequency transformer” means that the transformer should not and could not be adjusted over the site during operation or at any time during the service life of the system, the transformer is a passive dedicated unit, namely , a passive frequency raising device or a passive frequency reducing device, contrary to an underwater VSD. An underwater VSD is very complex, large and expensive, and is typically about 12 m high, 3 m in diameter and weights around 200 tons. The passive transformer will, on the contrary, be much smaller and simpler,
    Petition 870190111975, of 11/01/2019, p. 20/62
    15/51 typically presenting 6 m in length and 2 m 3 m in diameter, weighing about 50 tons. The reliability of the transformer is estimated to be several times better than for an underwater VSD. This is due to the fact that an underwater VSD is very complex, and although all components are of excellent quality, the large number of components and complexity, result in reduced reliability in practice. The cost of the system of the present invention will be significantly reduced compared to systems of the prior art having an underwater VSD. The term other loads includes energy to control systems and other loads not necessarily related to pressure increase.
    [0025] The electrical input and output frequency of the passive electrical frequency transformer will be different. The difference will be in a fixed relationship to the extent that the transformer is passive. The input frequency, the operating frequency of the cable, will be in the range of 0 Hz - 150 Hz, such that 2 Hz - 60 Hz or 4 Hz - 50 Hz or 5 Hz - 40 Hz, while the output frequency will be in the range of 0 Hz - 350 Hz, such as 30 Hz - 300 Hz, 50 Hz - 250 Hz or 50 Hz - 200 Hz. The submarine frequency transformer can be arranged in one or several housings, as one or several elements, however , all parts of it must withstand the harshest underwater environment without fail. With the present invention, the cost and long-term reliability of said submarine transformer, and associated systems,
    Petition 870190111975, of 11/01/2019, p. 21/62
    16/51 improve significantly on what is currently obtainable, for example, with underwater solid state variable speed drives.
    [0026] The frequency of operation of the cable has to be considered taking into account the Ferranti effect and electrical losses. Isolation is a key element. Most preferably, the dimensions of conductors and insulation, and the choice of operating frequency, are such that at the far end of the cable, the Ferranti effect increases the voltage exactly as much as the electrical losses, therefore, overvoltage at the free end due the fact that the Ferranti effect is avoided and the cable design is simplified. The guidance provided in this document, combined with good engineering practice, is assumed to be sufficient for appropriate cable design, including choice of operating frequency. The solution should be found in each case. The passive electric frequency transformer is then designed to transform the operating frequency of the cable to the operating frequency of subsea loads, that is, subsea compressors or subsea pumps, or more specifically, the engines of subsea compressors or pumps underwater.
    [0027] The present invention also provides a passive electric frequency transformer, for operative connection between a distant end of submarine cable and subsea loads for pressure elevation, a badge in which said transformer is located in a pressure vessel and transforms the frequency of the cable
    Petition 870190111975, of 11/01/2019, p. 22/62
    17/51 submarine for a frequency suitable for operation of the connected loads. The transformer increases the frequency of electrical energy (in the range of 1.1 times to 5 times the increase, for example) or decreases the frequency (in the range of 0 to 0.9 times the frequency, for example) of electrical energy. Preferably, the transformer comprises an electric motor and an electric generator having a
    common axis, the number in pole of the generator is one multiple of number in pole of the engine, and The transformer is preferably built-in in one accommodation pressure, one pressure compensator is
    arranged in the pressure housing and for high energy normally a penetrator is provided for each phase of a three phase input connection and a three phase output connection. Alternatively, particularly for low relative energy, a common penetrator for all three input and output phases can be used, or more preferably, a common penetrator for both the input and output phases. Alternatively, the transformer comprises one of: a mechanical gear, a dynamic or hydraulic fluid gear, a dynamic mechanical fluid gear, a magnetic gear, a static passive (solid state) lifting device or a rectifier.
    [0028] The present invention also provides an alternative submarine pressure lifting system suitable for operation at submarine distances above the 40 km range, a distinctive feature in which the system comprises:
    - at least one power cable
    Petition 870190111975, of 11/01/2019, p. 23/62
    18/51 submarine, disposed from a nearby end at an onshore location or dry tops for one or more subsea loads such as subsea pumps or subsea compressors or other charges at a distant end, at the near end at least one source for energy electrical at constant frequency is connected and the cable is sized for operation at that frequency or a lower frequency, in which case a passive frequency reduction device is connected towards the end of the submarine cable in order to manipulate the Ferranti effect and losses electrical; and
    - at least one active electrical frequency transformer, operably connected between the distant end of the underwater cable and the underwater loads, said transformer being located in a pressure vessel and transforming the operating frequency of the underwater cable to a frequency suitable for the operation of the loads connected.
    [0029] The alternative system is for connection to a constant frequency power source, such as a 50 Hz power source, in which case adjustments occur at the far end of the cable, but preferably controlled from a control room. upper parts or onshore, therefore, the expression active electrical frequency transformer. That is, contrary to the state of the art teaching the prescription of active control devices at both ends of the submarine cable. If the constant frequency is too high for the distance,
    Petition 870190111975, of 11/01/2019, p. 24/62
    19/51 for the cable conductor and dimensions and type of insulation, a frequency reduction device is connected to reduce the frequency of cable operation. The alternate system's active electrical frequency transformer comprises at least one of: a controllable mechanical gear, a dynamic or hydraulic fluid adjustable gear, a mechanical fluid dynamic adjustable gear, an adjustable magnetic gear or a single common underwater variable speed drive for various underwater loads; operatively connected between the far end of the submarine cable and the underwater loads in order to control the speed of the connected loads by adjusting the transmission ratio or frequency elevation ratio.
    [0030] The present invention also provides a method for operating a subsea pressure lifting system in accordance with the present invention, a distinctive in which the method comprises:
    [0031] adjust the speed of connected loads by merely adjusting the operating parameters of equipment connected to an end close to upper parts or onshore location of an underwater cable.
    [0032] All subsea equipment is passive slave equipment, adjustments are only required and possible in upper parts or onshore locations at the cable free end, contrary to state of the art systems.
    [0033] In an alternative method of
    Petition 870190111975, of 11/01/2019, p. 25/62
    20/51 present invention, using the alternative system of the present invention, the only active adjustment is at the free end of submarine cable.
    [0034] The present invention also provides a method for elevating subsea pressure, using a subsea pressure elevating system of the present invention, suitable for elevating pressure by operating subsea pumps and subsea compressors over subsea distances above 40 km and by control merely from a dry top or onshore location, distinctive in which the method comprises:
    - arrangement and dimensioning of at least one subsea power cable, from a nearby end at an onshore location or dry tops for one or more subsea loads such as subsea pumps or subsea compressors at a distant end, at the near end of the connection at least one source for electrical energy and cable dimensioning for operation at a different frequency than the operating frequency of underwater loads connected in order to manipulate the Ferranti effect and electrical losses;
    - transformation of the cable frequency in at least one passive electrical frequency transformer, operably connected between the distant end of the submarine cable and the subsea loads, to a frequency suitable for operation of the connected loads; and
    - system operation.
    [0035] Additionally, this
    Petition 870190111975, of 11/01/2019, p. 26/62
    21/51 invention provides the use of a subsea pressure elevation system in accordance with the present invention, for subsea pressure elevation operation of pumps or compressors at a distant end of a subsea cable, where the subsea distance can exceed 40 km and the pressure increase does not require subsea control.
    [0036] Finally, the present invention provides the use of a passive electrical frequency transformer in accordance with the present invention, for operative connection between a distant end of submarine cable and subsea loads for pressure elevation.
    The modality of the present invention with elevation of frequency to operate AC motors [0037] One modality of the present invention, the Fourth Solution, is shown in Figure 4 and Figure 5. The main feature of the modality is the introduction of an elevation device frequency step-up device (FSD) located submarine at the far end of the transmission cable and a short distance from the engines that operate the compressors and pumps. Short distance means, in this context, close enough to keep the drop in ohmic resistance acceptable and, as a result, loss of energy between the generator and the motors, and means short enough to avoid problems caused by the Ferranti effect and instability. It is important to note that FSDs are not directly controlling the frequency to match the speed
    Petition 870190111975, of 11/01/2019, p. 27/62
    22/51 engine operation by having a local control system that adjusts the speed according to needs. The speed variation in accordance with the need for steady-state production, start and stop and downward and upward ramp speed, is made by the VSD of near-end surface (upper parts on platform or onshore) located far from the submarine FSDs. FSDs are typically slaves to VSD and their purpose is solely to increase the transmission frequency determined by VSD by some multiple.
    [0038] This elevation is more easily achieved by using a submarine electric motor whose axis is coupled to a submarine electric generator, and both machines running at the same speed, that is, subsea rotating frequency step-up device - SRFSD). Any type of coupling (for example, flexible, rigid, common shaft of engine and generator, hydraulic, fluid) can be used that determines the same speed as motor and generator. The engine should preferably have 2 poles to keep the transmission frequency as low as possible, while the number of poles of the generator will be chosen in accordance with the need for lifting from a transmission frequency that is low enough to not to determine the previously described problems caused by the Ferranti effect, instability and high resistance, due to the fact of a skin effect with corresponding
    Petition 870190111975, of 11/01/2019, p. 28/62
    23/51 unacceptable voltage drop; that is, within a “problem-free frequency range”.
    [0039] For if to possess one engine 2 poles and one generator 4 poles, The relationship in elevation will be 2: 1, one generator in 6 poles will
    determine a 3: 1 ratio and an 8-pole generator a 4: 1 ratio, and so on, depending on the number of poles of the generator. This means that if the frequency from a surface VSD is in the 50 Hz range, the subsea frequency from the subsea RFSD device will be in the 100 Hz range corresponding to a 2-pole motor revolution speed from 6,000 rpm. If using an 8-pole generator, the corresponding lifting frequency will be in the 200 Hz range and the speed of a 4-pole motor at 12,000 rpm. These examples clearly demonstrate that the present invention can supply any frequency required for realistic engine speeds by a correct combination of engine and generator poles of the rotating submarine RFSD and at a trouble-free transmission frequency.
    [0040] Usually The relation of elevation can be expressed as: fs - u = n x ft Where: ft: frequency of transmission, Hz; fs - u: frequency in elevation -
    input frequency for motors, Hz; and n: multiples of 2, 3, 4 and so on, depending on the number of poles of the generator compared to the engine.
    Petition 870190111975, of 11/01/2019, p. 29/62
    24/51 [0041] The free frequency range problem has to be calculated on a case-by-case basis. For distances above, for example, 150 km, a transmission frequency above, for example, 75 Hz could be within the trouble-free range that will determine a 2-pole compressor motor speed of 2 x 75 x 60 =
    9,000 rpm, if the elevation ratio is 2: 1 (2-pole motor and 4-pole generator). If 75 Hz is found to be high to be trouble free, a 3: 1 lift ratio (2-pole motor and 6-pole generator) can be applied, which for the given example will reduce the transmission frequency to the maximum 50 Hz. The transmission frequency will not remain constant throughout the transmission period integrity of the oil or gas field, but has to be adjusted over time as the pressure in the wellheads decreases. For a given case, the transmission energy from the near end could be 33.3 Hz at the beginning and 50 Hz at the end of production, corresponding to a speed of between 6,000 rpm and 9,000 rpm of a
    compressor engine 2-pole at far end distant. [0042] By selection gives relation of elevation correct by selection of poles engine and
    generator, it will probably be possible to transmit trouble-free AC power to underwater engines with a distance from the near end to the far end of 300 km or more.
    [0043] Use of a 2-motor
    Petition 870190111975, of 11/01/2019, p. 30/62
    25/51 poles is beneficial for keeping the transmission frequency as low as possible. In the presence of other reasons, for example, torque and power, that should be verified favorable to use an engine with a higher number of poles, it would still be possible to achieve a desired elevation by selecting the number of poles of the generator correspondingly, for example, a 4-pole motor and a 12-pole generator that will determine a 3: 1 lift ratio.
    [0044] An advantage for using low frequency and a 4-pole motor is that the speed of the motor and generator will be low and so will the corresponding friction losses in the motor. This opens for the use of an oil-filled engine and generator arranged in a common pressure housing.
    [0045] If, for example, the transmission frequency is 25 Hz and a 4-pole motor is used, the rotational speed will only be 750 rpm, which will result in low friction losses. To achieve a frequency of 150 Hz from the generator, it must be 24 poles. By varying the transmission frequency from 18 Hz to 28 Hz, the frequency from the generator will vary in the range from 6,480 Hz to 10,080 Hz, which could be suitable for a compressor engine.
    [0046] The selection of the region of the variable transmission frequency and the consequent necessary elevation ratio will, consequently, be based on a frequency low enough to have a
    Petition 870190111975, of 11/01/2019, p. 31/62
    26/51 stable transmission over a given distance and keep the Ferranti effect and the skin effect low combined with an adequate number of poles and torque of the engine and generator. In addition, if the oil-filled engine and generator are preferred, the speed must be kept below some limit to avoid excessively high friction losses; typically a speed of 750 rpm to 1,500 rpm could be favorable, that is, a 25 Hz transmission to obtain 750 Hz for a 4-pole motor and 1,500 rpm for a 2-pole motor.
    [0047] Subsequently, it is determined as an example, a Table that shows the speed resulting from a 2-pole submarine compressor engine using a 4-pole motor generator set and a 12-pole generator set.
    Table
    Transmission frequency, Hz Motor speed4 poles, rpm Generator output frequency 12-pole, Hz 2-pole compressor drive speed, rpm 5 150 15 900 10 300 30 1,800 20 600 60 3,600 25 750 75 4,500 30 900 90 5,400 40 1,200 120 7,200 50 1,500 150 9,000 60 1,800 180 10,800 70 2,100 210 12,600
    Petition 870190111975, of 11/01/2019, p. 32/62
    27/51
    80 2,400 240 14,400
    [0048] The Table shows that a transmission frequency range above 50 Hz will cover the most effective speed range for compressors.
    [0049] Subsequently, a similar Table is determined for a compressor motor with 2 poles, a motor of 6 poles for the set of motor-generator and generator of 24 poles.
    Table
    Transmission frequency, Hz Motor speed6 poles, rpm Generator output frequency 24-pole, Hz 2-pole compressor drive speed, rpm 1 20 4 240 5 100 20 1,200 10 200 40 2,400 20 400 80 4,800 25 500 100 6,000 30 600 120 7,200 40 800 160 9,600 50 1,000 200 12,000 60 1,200 240 14,400 70 1,400 280 16,800
    [0050] In this case, a transmission frequency above 40 Hz will be sufficient.
    [0051] The above Tables clearly demonstrate that the transmission frequency can be kept low to avoid problems caused by
    Petition 870190111975, of 11/01/2019, p. 33/62
    28/51 Ferranti effect and skin effect.
    [0052] Compressor package selection is also a factor that assists in determining freedom in selection of transmission frequency and frequency elevation ratio, that is, a package can be selected, within reasonable limits, to suit one (fs- u) resulting from an optimized transmission system.
    [0053] A submarine RFSD is, in principle, very simple and no control system is required due to the fact that the lift frequency will be automatically obtained as a result of the pole relationship of the generator relative to the motor poles of the SRFSD .
    [0054] Another advantage with a subsea speed lifting device is that the current and the output voltage will have a practically perfect sine waveform that is beneficial for the motors, that is, no electrical filter for smoothing is necessary to achieve this.
    [0055] The submarine RFSD also supplies inductance to the transmission system, which due to the cable, has an excess capacitance, and the SRFSD, consequently, reduces the need for close-phase electrical phase compensation.
    [0056] There will be some loss of energy in an SRFSD, say 5%, but an underwater VSD will also show losses, however, perhaps lower.
    [0057] The selection of SRFSD has to,
    Petition 870190111975, of 11/01/2019, p. 34/62
    29/51 evidently, being such that the output energy of the generator at a certain frequency is such that it corresponds to the demand of the connected motor (s). If, for example, a 2-pole compressor engine were to determine 10 MW at 1,000 rpm, the power output of the generator must, accordingly, be a little extra to cover for losses at a frequency of 167 Hz. SRSFD's engine has to correspondingly determine a 10 MW shaft energy plus some additional to cover for losses.
    [0058] Another way than to have different poles of the motor and generator of the motor-generator set, may be to include a lifting gear fixed among, for example, the ratio 3: 1. If the transmission frequency, for example, is 50 Hz, a 4-pole motor will have a speed of 1,500 rpm and the generator speed will be 4,500 rpm with an output frequency of 150 Hz that determines a compressor traction 2-pole at a speed of 9,000 rpm. A combination of fixed lift and generator pole number can also be used to keep the pole number down if it is favorable. If, for example, a lifting gear with a 2: 1 ratio is inserted between a 4-pole motor and an 8-pole generator, the motor speed at 50 Hz will be 1,500 rpm, the generator speed 3,000 rpm and its frequency output of 200 Hz and the traction speed of 112,000 rpm.
    Because it has VSD at the close end, the traction speed can be adjusted to appropriate values by adjusting the transmission frequency
    Petition 870190111975, of 11/01/2019, p. 35/62
    30/51 in the range above 50 Hz.
    [0059] In some cases, a fixed transmission frequency and, as a consequence, a fixed frequency from the generator can be maintained and, therefore, a fixed speed of the connected motor, for example, a compressor, a pump motor. multiple or single phase. If the engine runs on a compressor, the compressor speed can, for example, be maintained at 9,000 rpm, and an adequate flow capacity and compressor pressure ratio, which will vary over time, can be adjusted by recovery and some recirculation. This will determine the simplest and lowest CAPEX of the total system, but with some higher energy losses due to periods with recirculation over the compressor. A more frequent recovery of the compressor may also be necessary compared to variable frequency. An optimized energy transmission and compression system have to be based on calculations to establish an optimized system design from case to case.
    Submarine RFSD Project (Rotating Frequency Stepup Device)
    Alternative Oil Filled Pressure Housing 1 [0060] The engine and generator are mounted in a common pressure housing with an adequate number of sealing flanges. In addition, there are several options for the practical project, which are listed below:
    Petition 870190111975, of 11/01/2019, p. 36/62
    31/51 [0061] The motor-generator has an adequate number of bearings. The rotational speed of the motor-generator is low enough to maintain acceptable friction losses, and the common pressure housing is filled with a suitable liquid, for example, oil, which lubricates the bearings and also cools the motor and generator and the properties of the selected oil should preferably be such that they serve as electrical insulator.
    [0062] Rather than oil , accommodation can be filled with water or with a mix in Water and antifreeze agent, per example, MEG, what requires a electrical insulation complete of motor coils and generator. [0063] The pressure at the inland of accommodation can be selected freely by no filling in even completely with liquid and
    have a volume of gas at some pressure.
    [0064] A favorable solution is to fill the housing with liquid and have a pressure balancing device between ambient sea water and the internal liquid in the pressure housing. This will result in a minimum thickness of the pressure housing and also reduce the load and requirements for flanges and seals.
    [0065] If the direct cooling of the motor-generator by heat flow through the pressure housing and the sea is excessively
    low, should be included one circuit in external cooling with changer in heat for The ambient sea water. [0066] A pump for The circuit in refrigeration can favorably to be coupled to
    Petition 870190111975, of 11/01/2019, p. 37/62
    32/51 motor-generator shaft or the same can be a separate pump with electric motor.
    [0067] If magnetic bearings for liquid operation are available, this could be an option for liquid lubricated bearings. For more details about this, reference is made to the later description for gas-filled housing.
    Gas Filled Pressure Housing [0068] The pressure housing can be filled with an inert gas, for example, dry nitrogen or dry air. The advantage of this is that the friction losses are lower than oil-filled, which allows for higher engine-generator speed. In addition, the practical solution may include the following:
    [0069] Bearings lubricated by liquid (for example, oil, water or water / MEG) with a circulation circuit through an external heat exchanger or only inside the housing.
    [0070] At least one pump for the lubricant, either driven by the motor-generator shaft or by a separate electric pump.
    [0071] If necessary, a refrigeration circuit for the gas is included because it has at least one fan to circulate the gas inside the enclosure or, if necessary, through an external heat exchanger.
    [0072] Alternatively, for liquid-lubricated bearings, magnetic bearings can be used. The gas cooling system must then be dimensioned to also cool the magnetic bearings.
    Petition 870190111975, of 11/01/2019, p. 38/62
    33/51 [0073] A control system for magnetic bearings must be included, located adjacent to the motor-generator housing or inside the housing or on a surface on a platform or onshore. If the control system is located in a housing outside the motor-generator housing, penetrators through the housing wall are required, as well as cables for energy and signals between the control system and the magnetic bearings. If the control system is in an enclosure, the enclosure can be designed to be separately recoverable or not.
    [0074] The pressure inside the housing can be selected from a bar and even match the ambient or higher sea water pressure. The advantage of low pressure is friction and low losses. The advantage of high pressure is that the heat capacity of the gas increases with pressure and, consequently, determines better cooling. Another advantage of high pressure is also that of reduced requirements for wall thickness and lower load on flanges and seals. If the pressure is selected nearby to match the ambient seawater pressure, the resulting requirements for the pressure housing and flanges and seals will be similar to a pressure-balanced vessel filled with liquid.
    Submarine Rotation VSD [0075] Previously, the use of hydraulic or fluid coupling between the engine and the generator in the engine set was mentioned
    Petition 870190111975, of 11/01/2019, p. 39/62
    34/51 generator. Such a coupling has the advantage of determining “soft start”, that is, the generator load on the motor is not intermediated, but upward ramps over time, such that a high peak inrush current is avoided. The use of such a coupling can be further expanded to make the coupling adjustable such that the speed of the generator can be adjusted relative to the constant motor speed. In this way, the motor-generator set can be used as an underwater variable speed drive, that is, underwater speed variable speed drive (RVSD), and the upper VSD can be omitted.
    [007 6] Instead of a fluid coupling, a mechanical gear can be used to increase and decrease the speed of the generator, and as a result, its output frequency.
    [0077] If a variable coupling of some kind (fluid or mechanical) is used, the control system for the variable coupling can be in a separate enclosure externally for the SRVSD or it can preferably be located on the surface and preferably connected to the or integrated into the global control system for the subsea lifting station, compressor station or subsea processing plant or other system with variable speed subsea engines.
    [0078] It is important to note that if this SRVSD is applied, the upper parts VSD becomes superfluous and the system with both surface
    Petition 870190111975, of 11/01/2019, p. 40/62
    35/51 and how much with SRVSD is not an effective solution of this present invention.
    Submarine Static Frequency Elevation Device [0079] Alternatively, for an RFSD can be used, an underwater static VSD is provided such that a device, when modified to suit the simple purpose of being a transmission frequency elevation device, can be made in a simplified version with acceptable high robustness, reliability and availability. An obvious simplification seems to be that the control system computer for adjusting the elevation ratio can be located on the surface and connected to or integrated into the control system for the surface VSD that actually controls the speed of the motors. The only function of the subsea static frequency elevation device (SFSD) is to increase the transmission frequency with an adjustment elevation ratio, n: 1. There is no need for very quick response locally for the submarine SFSD, which consequently allows for an edge location close to it.
    [0080] A surface-based control system is evidently much easier to maintain and repair than that of a submarine located, and will, consequently, significantly increase the availability of the subsea SFSD.
    [0081] An obvious advantage with a submarine SFSD compared to a submarine RFSD, is that
    Petition 870190111975, of 11/01/2019, p. 41/62
    36/51 that the elevation ratio can be readjusted in some points of time if it is beneficial, for example, by increasing the ratio from 2: 1 to 3: 1.
    [0082] The input signal to the control system for the submarine SFSD is the transmission frequency and the output is a signal that increments three frequencies of the electric power output of the submarine SFSD with an adjustment ratio that is suitable for the speed effective engine (s).
    [0083] Also, in this case, the general expression is as follows:
    f s - u = nx ft where:
    n = a multiple that does not necessarily have to be an integer, but can be adjusted to any desired value, for example, 2.3; which is different from an RFSD, where the number of generator poles relative to the motor poles will result in (n) being an integer.
    [0084] a SFSD can alternatively for adjustment in an frequency ratio, be programmed for increment the frequency by one determined increase added, for example, add 100 Hz, for a frequency of streaming in 50 Hz , or in a more generic: fs - u = ft + Afa
    Where:
    ft = frequency transmission, Hz; f s - u = frequency in elevation
    input frequency for motors, Hz; and
    Petition 870190111975, of 11/01/2019, p. 42/62
    37/51 fa = added frequency, Hz.
    [0085] Some elements of a practical solution may include:
    [0086] The components of the subsea SFSD can be mounted in a pressure vessel filled with a suitable liquid, for example, insulating oil which is also cooling the electronic and electrical components.
    [0087] The internal oil can be balanced in pressure to ambient sea water or the pressure can be maintained at a level between one bar and ambient pressure decided by the pressure tolerance of the components.
    [0088] The control system can be
    located inside of accommodation pressure, but more favorable in a wrapper external separate (reference is made to description
    previously gas-filled Accommodation for details).
    [0089] The control system can be located on the surface (upper parts or onshore).
    [0090] Alternatively, for a vessel filled with liquid, a vessel filled with dry, inert gas, for example dry nitrogen, can be used.
    [0091] The pressure inside the housing can be selected from the region of a bar and even to match the ambient or higher sea water pressure. The advantage of high pressure is that the heat capacity of the gas increases with pressure and, consequently, determines
    Petition 870190111975, of 11/01/2019, p. 43/62
    38/51 better cooling. Another advantage of high pressure is also the reduced requirement for wall thickness and lower load on flanges and seals. If the pressure is selected close to equal the ambient seawater pressure, the resulting requirements for the pressure vessel and flanges and seals will be similar to a pressure-balanced vessel filled with liquid. It is the pressure tolerance of the components inside the vessel (that is, electronic, electrical, others) that will decide the pressure limitation.
    [0092] If favorable, the submarine SFSD components can be segregated in an optimized manner in accordance with their tolerances for: liquid, pressurized liquid and pressurized gas. The components can be arranged in pots as follows:
    [0093] The most robust components can be installed in a vessel filled with pressurized liquid.
    [0094] Liquid tolerant components that have low pressure tolerance can be installed in another vessel filled with low pressure liquid.
    [0095] Components that do not tolerate liquid, but tolerate high pressure gas, can be installed in a high pressure vessel.
    [0096] Components that only tolerate low pressure gas can be installed in a vessel with low pressure gas.
    [0097] Adequate refrigeration must be applied to the different vessels.
    Petition 870190111975, of 11/01/2019, p. 44/62
    39/51 [0098] Components in the various vessels will be connected as needed by cables going through penetrators in the vessel walls. Submarine pairs capacity connectors can also be arranged between vessels to make them separately installable and retrievable.
    [0099] It should be mentioned that the segregation previously described to achieve an optimized arrangement of the components of a subsea SFSD in different vessels, taking into account the number of penetrators and connectors needed, can also be applied for subsea variable speed traction (VSD) . Some Considerations [00100] An important point of the present invention is that although a VSD is typically used in close proximity, it is not important to be able to quickly adjust the frequency of the motor loads. The engine speed is slowly adjusted over the years as the reservoir is produced and the field pressure gradually decreases, consequently, requiring increased energy, that is, engine speed. This fact makes it possible, for example, to temporarily decrease the operation of motors in order to connect one more motor.
    Alternatively, the unused motor can be connected directly under load, if calculations have shown that it is suitable with respect to current peaks or other disturbances of the power transmission system. Depending on the number of engines already running, it may be beneficial to temporarily reduce the frequency before
    Petition 870190111975, of 11/01/2019, p. 45/62
    40/51 DOL departure (directly online - direct online). If necessary, the power can be turned off when starting an additional engine and starting and increasing the speed of all engines simultaneously. In a compression station, another option is to put all pumps and compressors in recirculation before starting a compressor or pump that has been stopped, then starting the unit stopped and when it has reached the desired speed, put all compressors and pumps online in production mode.
    [00101] The aforementioned devices and methods make it possible to manage the Ferranti effect and the skin effect and, as a result, considerably extend the distance for submarine high voltage energy transmission.
    [00102] Therefore, maximum practical distance can be much further increased without the introduction of underwater VSDs with local underwater frequency control.
    [00103] In both Figure 4 and Figure 5, the lifting devices do not have a local control system that varies the frequency and, as a result, the speed of motors in accordance with production, nor do they directly control the reduction of frequency to add operation of motors that were stopped, and neither do they directly control the elevation of the frequency to obtain the effective speed of the motors to adapt the production.
    Petition 870190111975, of 11/01/2019, p. 46/62
    41/51 [00104] If the
    RFSD has oil-lubricated bearings, there is no need for any unit control system, and possible instrumentation can be limited to monitoring, for example, vibrations and temperature, if found beneficial.
    00105] As mentioned in the section:
    previously, the speed of compressors can typically be in the range from, for example, 4,000 rpm to 14,000 rpm, and pumps from, for example, 2,000 rpm to 5,000 rpm. When compressor and pump motors in a compression station in accordance with the present invention (Fourth Solution and Fifth Solution) are supplied with the same frequency by a common transmission cable, the speed of the pumps can easily be adjusted to the desired speed of half the compressor speed by using motors with four or more poles for pumps and motors with two poles for compressors. If the pumps are used to control the liquid level of a separator in a compressor station, a forward flow of variable network suitable for the pump can be arranged by recirculation and equipped with flow control valves.
    [00106]
    The speed of the pumps can therefore be controlled in the following optional ways:
    [00107] Dedicated submarine FSD for each pump motor;
    [00108] A common FSD for several pump engines;
    Petition 870190111975, of 11/01/2019, p. 47/62
    42/51 [00109] Operate the pump motors on the same frequency as the compressors, but with the doubled number of poles resulting in half the rotational speed;
    [00110] Operate the pumps on the transmission frequency.
    [00111] Generally, for the number of subsea FSDs, whether they are RSFSs or SFSDs, their numbers can be from one unit per engine to a large common unit for all engines or something among them, for example, an FSD by large compressor-motor and a common unit for very small pump motors or, as mentioned earlier, no FSD for pump motors.
    Some suggested combinations of VSDs located on the surface, number of underwater traction and number of 3-phase transmission line [00112] A 3-phase transmission line consists of three individual cables that are insulated and bundled together. For long submarine transmission with more than one engine, for example, with two compressors, it is possible, with the present technology, to package two transmission lines for two engines together, that is, six cables in the package. This will reduce the cost of depositing the lines and has the advantage of allowing individual frequency control of two motors at the far end of the two lines that are packed together. There is a lifting device per motor. Such an arrangement is shown in Figure 7. In this case, the motor is of the high voltage type and the
    Petition 870190111975, of 11/01/2019, p. 48/62
    43/51 transmission can be, for example, 100 kV and there is no need for subsea transformers. In such a case, the circuit breaker must be located after the generator where the voltage is acceptable due to the fact that subsea circuit breakers for very high very high voltages of 100 kV are not currently available.
    [00113] Another way, which results in a lower investment, is the solution shown in Figure 4, and with a hydraulic soft starter between the M motor and the G generator, such that the (M1) (M4) motors can occur starting individually without unacceptable starting currents. All engines will operate at the same speed, which is not a problem for similar machines, for example, compressors.
    [00114] The least complicated arrangement is that of Figure 4 without smooth initiator. In this case, it will be necessary to start all the compressors simultaneously, and this is a little inconvenient, but not considered a problem due to the fact that the number of starts per year is limited.
    [00115] Numerical references are listed in Table 2.
    Table 2: numerical references.
    Item # Explanation 1 Electricity supply grid 2, 2 ', 2' ', 2' '' Reduction transformer 3, 3 ', 3' ', 3' ' Variable Speed Traction, VSD 4, 4 ', 4' ', 4' ' Lifting transformer
    Petition 870190111975, of 11/01/2019, p. 49/62
    44/51
    5, 5 ', 5 '', 5 '' ' Transmission cable 6 , 6 ', 6 '', 6 ''' Reduction transformer 7, 7 ', 7 '', 7 '' ' Circuit breaker 8, 8 ', 8 '', 8 '' ' Cable end close tostreaming 9, 9 ', 9 '', 9 '' ' Far end of cablestreaming 10 Common package of two or more power transmission lines 11 Pressure housing 12 Inert or liquid gas 13, 13 ', 13 '', 13 '' ' Reduction transformer 14, 14 ', 14 '', 14 '' ' VSD 15, 15 ', 15 '', 15 '' ' Circuit breaker 16, 16 ', 16 '', 16 '' ' Rectifier 17 Fluid coupling (optional)(hydraulic), variable speed fluid gear (optional) or housingfixed rate gears (optional)18 18 'Penetrator 19 Pressure balance unit M1, M2 , M3, M4 Motor M Subsea Rotating Frequency Lifting Device (Subsea RFSD) G Subsea Rotating Frequency Lifting Device Generator
    Detailed description [00116] Reference is made to Figure 4, illustrating a specific embodiment of the present invention. Node 1 is connected to an electrical power source; the source is a power grid
    Petition 870190111975, of 11/01/2019, p. 50/62
    45/51 local or, for example, a local power generation system. A VSD 3 is a connection to the power source. A VSD input transformer 2 is often connected between them in order to adjust the supply voltage, for example, 13.8 kV for a platform for the rated VSD voltage, for example, 6 kV. The transformer can be an integrated part of the VSD as offered by some suppliers. Typically, a lift transformer 4 is required to connect the VSD 3 to the high voltage transmission line 5 which, in the example of an underwater application, consists of a cable. A typical voltage applied to the cable could, for example, be about 120 kV. The cable is deposited at sea so as to extend from the near end 8 to the distant underwater end 9; the cable has any operating length where the Ferranti effect starts being observed to the extent that it strongly dominates the current and load. This can be translated into a length of the order of 20 km, to 100 km and probably moreover, dictated by the location and properties of the underwater loads. At the far end 9 of the cable, a submarine transformer 6 is arranged, reducing the voltage to, for example, 20 kV suitable for circuit breakers 7, 7 ', 7' ', 7' '', followed by transformers 13, 13 ', 13' ', 13' '' decreasing to, for example, 6 kV suitable for engines of subsea RFSDs or the operating voltage of SFSDs, which is also a suitable voltage for engines M1, M2, M3, M4. Four underwater engines are illustrated, which, for example, can be two
    Petition 870190111975, of 11/01/2019, p. 51/62
    46/51 compressors motors M1, M2 and two pump motors M3, M4.
    [00117] The reduction transformers are, in principle, optional due to the fact that the reduction transformer 6 (reference to Figure 4 and Figure 5) can directly decrease the voltage suitable for the subsea FSDs illustrated in Figure 5. Inclusion of transformers 13, 13 ', 13' 'and 13' '' is a matter of optimization of the far-end power distribution system.
    [00118] The subsea RFSDs in Figure 4 and Figure 5 increase the transmission frequency with a desired elevation ratio by selecting Engine M and Generator G.
    [00119] No figure illustrating the use of subsea SFSDs is included, but can be understood by simply exchanging the RFSDs in Figure 4 and Figure 5 with SFSDs.
    [00120] It should be emphasized that the key components of the power transmission systems of Figure 4 and Figure 5 are power source 1, VSD variable speed traction 3, transmission cable 5 and MG motor-generator set . The other components, that is, elevation and reduction transformers 2, 4, 6, and 14, 13 ', 13' ', 13' '', and circuit breakers 15, 7, 7 ', 7' ', 7' '' are included in accordance with the need from case to case.
    [00121] If, for example, the M motor of the motor-generator set is of the type with insulated cables in the stator, it can operate at a much higher voltage than motors with conventional coils. Therefore, both decrement transformers 4,
    Petition 870190111975, of 11/01/2019, p. 52/62
    47/51 and 13 can become superfluous. If additionally the M1 - M4 motors are running at the fixed speed of the lifting devices, the VSD 3 can be omitted.
    [00122] Another advantage of submarine high voltage motors with insulated stator cables is that these motors require less current (amps) through the penetrators through the motor housing than conventional voltage motors in the 6 kV range. This will make it possible for motors with higher energy than at the present stage where around 12 MW is the maximum due to the current capacity (ampere) limitation.
    [00123] The cost of long subsea cables and subsea VSDs is high, and subsea VSDs in Figure 2 have a negative impact on system reliability as well as being expensive. A common transmission cable compared to the solution in Figure 1, therefore, represents considerable investment savings.
    [00124] It should be mentioned that although a common transmission cable is beneficial for reasons of cost, there is technically no problem in having a transmission cable for each submarine FSD. This can be the optimized solution for medium distances, for example, from 35 km to 75 km, that is, up to distances where the cost of cable is not prohibitive. With a VSD by transmission cable, that is, a VSD by submarine engine, this results in individual speed control for each
    Petition 870190111975, of 11/01/2019, p. 53/62
    48/51 engine.
    Condensed description of the underwater lifting device of the present invention [00125] It is problematic, or even impossible, to transmit high-voltage, high-voltage electricity at high frequency, for example, of more than 100 Hz, over long underwater elevation distances , for example, of more than 40 km, to supply high speed engine operation for subsea pumps and subsea compressors. This is due to the fact of the Ferranti effect, which can create overvoltage and instability in the transmission system, as well as the skin effect that creates high ohmic resistance and, consequently, high voltage and energy losses.
    [00126] Submarine drives of variable speed for which the transmission frequency can be low, for example, of 50 Hz, present a solution for this. These are, however, large and equipped with a large number of sensitive and fragile electrical and electronic components and a control system, which in addition to making them expensive, are also assumed to have a high failure rate.
    [00127] The present invention offers a solution for this by having the VSD with its surface control system (on a platform or onshore) and, therefore, having unique subsea frequency elevation devices, both rotational or static, close to submarine engines. These devices
    Petition 870190111975, of 11/01/2019, p. 54/62
    49/51 do not directly control the frequency of the electric current for the motors, but their only functions are to increase the transmission frequency, which is variable and adjust in frequency according to the need of the motors, for an adequate ratio. In the case of subsea rotation frequency elevation devices, the resulting elevation ratio is derived from the ratio of the number of poles of the generator and the motor of the device. The relationship will therefore
    example, be of 2 if the generator is of 4 poles and the 2-pole motor. [00128] Devices in elevation submarines of rotation add inductance to
    transmission system and are consequently beneficial in counterbalancing the large capacitance of the cable and, consequently, the close end compensation system can probably be reduced.
    [00129] If static lifting devices are used, these can be simplified compared to underwater variable speed traction in that the lifting ratio can be fixed. Among other things, the elevation control system can be located on the surface and can either be connected to the VSD located on the surface or integrated into it.
    The present invention with submarine AC / DC rectification to operate DC motors [00130] Another embodiment of the present invention to make it possible to have frequency control located on the surface
    Petition 870190111975, of 11/01/2019, p. 55/62
    50/51 for speed control of underwater engines over long distances, is by rectifying AC transmitted to DC at an underwater location close to the engines. Close means, in this context, close enough to keep the drop in ohmic resistance acceptable and, in the meantime, loss of energy between the rectifier and the motors. Reference is made to Figure 6, which illustrates a transmission system from the VSD located on the surface for an undersea rectifier that supplies DC for subsea engines.
    [00131] The rectifier can be of the rotation type, in which case the static rectifiers 16, 16 ', 16' ', 16' '' will be replaced with rotation rectifiers which in reality are a motor-generator set of which the generator is a DC generator to which an underwater DC load, for example motor, is connected, as shown in Figures 4 to 8, but in this case, the generator is a direct current (DC) generator and the connected motor is a DC motor. The practical arrangement of a rotation rectifier in a pressure housing
    can be resembled available to a set motor-generator described previously.[00132] THE follow, will be better described use of static type with diodes solid state. [00133] THE speed rotation of
    motors will be in the manner established for DC motors, that is, control of bypass motors, in series or compounds.
    [00134] The speed of a DC motor
    Petition 870190111975, of 11/01/2019, p. 56/62
    51/51 is directly proportional to the supply voltage. Consequently, a suitable alternative way of adjusting the speed is to adjust the voltage from the DC generator.
    [00135] Alternatively, a common rectifier can be used in several motors. Individual speed control can, in such cases, be done by a bypass arrangement, in series or composite.
    [00136] With respect to the practical arrangement of the rectifier in a pressure vessel, reference is made to the preceding description of the
    device elevation in frequency static submarine due to the fact in that same can to be similar. [00137] So much the systems, and how much the methods, and the transformer frequency and at
    uses of the present invention, can include any feature or step described or illustrated in this document, in any operative combination, each operative combination is an embodiment of the present invention.
    [00138] The present invention has been described in terms of preferred principles, modalities and components. Those skilled in the art will understand that substitutions of equivalent structures, components and method steps can be made without departing from the scope of the present invention.
    权利要求:
    Claims (9)
    [1]
    1. Submarine pressure elevation system, suitable for operation at underwater distances above 40 km and for active control merely from a dry top or onshore location, characterized by the fact that the system comprises:
    an undersea power cable (5, 5 ', 5' ',
    5 '' ') arranged from a close end (8, 8', 8 '', 8 '' ') of the submarine power cable (5,
    5 ', 5' ', 5' '') in a dry onshore or upper location for an underwater load at a distant end (9, 9 ', 9' ', 9' '') of the submarine power cable (5 , 5 ', 5' ', 5' '');
    a power source connected to the near end (8, 8 ', 8' ', 8' ') of the submarine power cable (5, 5', 5 '', 5 ''), and where the cable subsea power (5, 5 ', 5' ', 5' '') is sized for a first operating frequency that is different from a second operating frequency of the underwater load in order to deal with the Ferranti effect and electrical losses; and
    an engine electric (M) and a generator electric (G) that are operatively connected between the far end distant (9, 9 ' , 9 ' ', 9' '') of cable of submarine energy (5, 5 ', 5 '', 5 '') and the underwater cargo of so to raise pas sively
    first frequency operation power cable submarine (5, 5 ', 5' ', 5' '' ) to the Monday operating frequency. 2. System, in wake up with the claim 1, characterized by the fact that the
    electric motor (M) and electric generator (G) are
    Petition 870190111975, of 11/01/2019, p. 58/62
    [2]
    2/4 embedded in a pressure housing (11), and in which a pressure compensator is arranged in the pressure housing (11) and a penetrator (18, 18 ') is provided for each phase of a three-way inlet connection phases and a three phase output connection.
    [3]
    3. System according to claim 1, characterized by the fact that the electric motor (M) and the electric generator (G) are arranged axially apart from each other on a common axis.
    [4]
    4. System, according to claim 3, characterized by the fact that the electric motor (M) and the electric generator (G) have a common axis and are located in a pressure vessel and the electric generator (G) comprises a pole number which is a multiple of an electric motor pole number (M).
    [5]
    5. Lift transformer (4, 4 ', 4' ',
    4 '' ') of passive electrical frequency, operatively connected between a distant end (9, 9', 9 '', 9 '' ') of an underwater cable and an underwater load for elevating pressure, characterized by the fact that the elevator transformer (4, 4 ',
    4 '', 4 '' ') of electrical frequency is embedded in a pressure housing (11) and raises a first operating frequency of the underwater cable to a second operating frequency suitable for operating the underwater load without using any means of active subsea control, the elevator transformer (4, 4 ', 4' ', 4' '') of passive electrical frequency comprising:
    an electric motor (M) and a generator
    Petition 870190111975, of 11/01/2019, p. 59/62
    3/4
    electric (G) having an axis common, wherein generator electric (G) comprises one number pole that is a multiple in a number in motor pole electric (M); one penetrator (18 , 18 ') for each phase of
    a three-phase inlet connection and a three-phase outlet connection, and a pressure compensator being arranged inside the pressure housing (11).
    [6]
    6. Lift transformer (4, 4 ', 4' ',
    4 '' ') of passive electrical frequency, according to claim 5, characterized by the fact that the electric motor (M) and the electric generator (G) are arranged axially apart from each other in relation to the common axis.
    [7]
    7. Method for operating a subsea pressure-lifting system, of the type defined in claim 1, suitable for raising the pressure by operating subsea pumps and subsea compressors over subsea distances above 40 km, characterized by the fact that the method comprises:
    adjust an underwater load speed by adjusting operating parameters of equipment connected to the near end (8, 8 ', 8' ', 8' '') of the submarine power cable (5, 5 ', 5' ', 5' ' ') without using any active subsea control means.
    [8]
    8. Method for operating a subsea pressure elevation system, suitable for elevating pressure by operating subsea pumps and subsea compressors over subsea distances above 40 km, characterized by the fact that the method comprises:
    have an undersea power cable (5,
    Petition 870190111975, of 11/01/2019, p. 60/62
    4/4
    5 ', 5' ', 5' ')) from a close end
    (8, 8 ', 8 '', 8 '' ') cable submarine power (5, 5 ', 5' ' , 5 '' ') for an underwater cargo in an far end (9, 9 ' , 9 '', 9 '' ') cable in energy submarine (5, 5 ', 5 '', 5 '' ');
    connect an electrical power source to the close end (8, 8 ', 8' ', 8' '') of the submarine power cable (5, 5 ', 5' ', 5' ');
    dimension the submarine power cable (5, 5 ', 5' ', 5' '') to operate on a first operating frequency that is different from a second operating frequency of the underwater load;
    transform the first operating frequency into a passive electrical frequency transformer, the passive electrical frequency transformer comprising an electric motor (M) and an electric generator (G) which are operatively connected between the far end (9, 9 ',
    [9]
    9 '', 9 '' ') of submarine power cable (5, 5',
    5 '', 5 '' ') and the underwater load, in order to passively raise the first operating frequency of the submarine power cable (5, 5', 5 '', 5 '' ') to the second operating frequency, being operatively connected between the distant end (9, 9 ', 9' ', 9' '') of the submarine power cable (5, 5 ', 5' ', 5' '') and the underwater load, and operate the system.
    类似技术:
    公开号 | 公开日 | 专利标题
    BR112013005951B1|2020-03-24|SUBMARINE PRESSURE LIFTING SYSTEM, PASSIVE ELECTRIC FREQUENCY LIFTING TRANSFORMER AND METHOD FOR OPERATING A SUBMARINE PRESSURE LIFTING SYSTEM
    CA2846208C|2020-03-24|Device for stable subsea electric power transmission to run subsea high speed motors or other subsea loads
    US10581360B2|2020-03-03|Power supply assembly and associated method
    US9859805B2|2018-01-02|Subsea electrical architectures
    US20140197764A1|2014-07-17|Device for stable subsea electric power transmission to run subsea high speed dc motors or other subsea dc loads
    JP2015512244A|2015-04-23|Electric unit for pumped storage power plant
    RU2618517C2|2017-05-04|System for ac transmission over very long distances
    AU2012341141A1|2014-05-08|System for very long subsea step-out transmission of electric DC power
    EP2889979A1|2015-07-01|Methods and systems for subsea boosting with direct current and alternating current power systems
    Lendenmann et al.2019|Shallow Water Testing of 9-12 MVA Variable Speed Drive for Subsea Installation
    US9774183B2|2017-09-26|Methods and systems for subsea direct current power distribution
    Normann et al.2015|Rotary Converter for Long Step-out Subsea Power Supply
    OA16664A|2015-12-01|Subsea electrical architectures.
    同族专利:
    公开号 | 公开日
    WO2012034984A3|2013-04-25|
    US20130169044A1|2013-07-04|
    CN103261571B|2016-08-31|
    WO2012034984A2|2012-03-22|
    GB2500495B|2018-10-31|
    RU2013116767A|2014-10-20|
    GB201306395D0|2013-05-22|
    BR112013005951A2|2016-05-17|
    RU2571117C2|2015-12-20|
    AU2011304028B2|2016-01-28|
    US9601925B2|2017-03-21|
    CN103261571A|2013-08-21|
    GB2500495A|2013-09-25|
    AU2011304028A1|2013-05-02|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    CH427978A|1960-09-09|1967-01-15|Kissling Marie Cecile|Electric rotating machine|
    US3558901A|1969-02-24|1971-01-26|Charles J Jacobus|Standby power system|
    GB1544300A|1976-08-18|1979-04-19|Toyo Electric Mfg Co Ltd|Quadruple frequency converter|
    JPS5324531A|1976-08-18|1978-03-07|Toyo Electric Mfg Co Ltd|Frequency converter|
    US6848267B2|2002-07-26|2005-02-01|Tas, Ltd.|Packaged chilling systems for building air conditioning and process cooling|
    SE519430C2|2000-03-15|2003-02-25|Abb Ab|Wind Power plant|
    US7615893B2|2000-05-11|2009-11-10|Cameron International Corporation|Electric control and supply system|
    NO313068B1|2000-11-14|2002-08-05|Abb As|Underwater transformer - distribution system with a first and a second chamber|
    US6707012B2|2001-07-20|2004-03-16|Shell Oil Company|Power supply for electrically heated subsea pipeline|
    GB2382600B|2001-12-03|2005-05-11|Abb Offshore Systems Ltd|Transmitting power to an underwater hydrocarbon production system|
    GB2418304B|2003-06-13|2006-11-08|Shell Int Research|System and method for transmitting electric power into a bore hole|
    US7216714B2|2004-08-20|2007-05-15|Oceaneering International, Inc.|Modular, distributed, ROV retrievable subsea control system, associated deepwater subsea blowout preventer stack configuration, and methods of use|
    NO20055727L|2005-12-05|2007-06-06|Norsk Hydro Produksjon As|Electric underwater compression system|
    EP1914872A1|2006-10-17|2008-04-23|Siemens Aktiengesellschaft|Wind farm|
    WO2009015670A1|2007-07-30|2009-02-05|Siemens Aktiengesellschaft|Energy transmission system, particularly for offshore oil installations|
    NO328415B1|2008-03-17|2010-02-15|Vetco Gray Scandinavia As|Device related to an offshore cable system|
    US8558416B2|2008-04-11|2013-10-15|Magtech As|Power transmission system|
    DE102008022618A1|2008-05-07|2009-12-31|Siemens Aktiengesellschaft|Power supply means|
    US8644037B2|2008-07-15|2014-02-04|General Electric Company|AC-AC converter with high frequency link|US20150036256A1|2010-07-30|2015-02-05|Exxon Mobil Upstream Research Company|Method for Design of Subsea Electrical Substation and Power Distribution System|
    US9859805B2|2011-06-01|2018-01-02|Total Sa|Subsea electrical architectures|
    US20130286548A1|2012-04-28|2013-10-31|Schneider Electric Industrues Sas|Subsea Electrical System Having Subsea Penetrator with Integral Current Sensor|
    US9379544B2|2012-04-28|2016-06-28|Schneider Electric Industries Sas|Subsea electrical distribution system operable to supply power to subsea load from plurality of sources|
    EP2901018B1|2012-09-12|2021-04-21|FMC Technologies, Inc.|Subsea multiphase pump or compressor with magnetic coupling and cooling or lubrication by liquid or gas extracted from process fluid|
    WO2014042630A1|2012-09-12|2014-03-20|Cunningham Christopher E|Subsea compressor or pump with hermetically sealed electric motor and with magnetic coupling|
    SG11201501905TA|2012-09-12|2015-05-28|Fmc Technologies|Up-thrusting fluid system|
    US10161418B2|2012-09-12|2018-12-25|Fmc Technologies, Inc.|Coupling an electric machine and fluid-end|
    WO2014079508A1|2012-11-23|2014-05-30|Abb Technology Ltd|An ac temporary load device and distribution system for operating an electric machine or electrical load powered by a long cable|
    US10221662B2|2013-03-15|2019-03-05|Fmc Technologies, Inc.|Submersible well fluid system|
    NO337300B1|2013-04-17|2016-03-07|Fmc Kongsberg Subsea As|Subsea høyspenningsdistribusjonssystem|
    EP2822136B1|2013-07-03|2018-08-29|Siemens Aktiengesellschaft|Method and arrangement for transferring electrical power for subsea applications|
    NO2822137T3|2013-07-03|2018-06-02|
    EP2822135B1|2013-07-03|2018-08-29|Siemens Aktiengesellschaft|Method and arrangement for transferring electrical power for subsea applications|
    EP2830171A1|2013-07-25|2015-01-28|Siemens Aktiengesellschaft|Subsea switchgear|
    US9951779B2|2013-12-27|2018-04-24|General Electric Company|Methods and systems for subsea boosting with direct current and alternating current power systems|
    US9439316B2|2014-04-03|2016-09-06|General Electric Company|Submersible power distribution system and methods of assembly thereof|
    NO337678B1|2014-05-26|2016-06-06|Fmc Kongsberg Subsea As|Subsea power distribution device and system.|
    US9899838B2|2014-06-25|2018-02-20|General Electric Company|Power delivery system and method|
    NO337348B1|2014-08-18|2016-03-21|Aker Subsea As|VARIETY SPEED OPERATING VARIABLE SPEED FOR LARGE PUMPS AND COMPRESSORS.|
    US20160215769A1|2015-01-27|2016-07-28|Baker Hughes Incorporated|Systems and Methods for Providing Power to Well Equipment|
    NO339736B1|2015-07-10|2017-01-30|Aker Subsea As|Subsea pump and system and methods for control|
    US10903653B2|2015-12-08|2021-01-26|Smart Wires Inc.|Voltage agnostic power reactor|
    US10008317B2|2015-12-08|2018-06-26|Smart Wires Inc.|Voltage or impedance-injection method using transformers with multiple secondary windings for dynamic power flow control|
    US10418814B2|2015-12-08|2019-09-17|Smart Wires Inc.|Transformers with multi-turn primary windings for dynamic power flow control|
    US10180696B2|2015-12-08|2019-01-15|Smart Wires Inc.|Distributed impedance injection module for mitigation of the Ferranti effect|
    US10199150B2|2015-12-10|2019-02-05|Smart Wires Inc.|Power transmission tower mounted series injection transformer|
    CN105577054B|2016-01-18|2018-06-01|中国石油大学|A kind of offshore oilfield electric submersible pump electric power system|
    US10097037B2|2016-02-11|2018-10-09|Smart Wires Inc.|System and method for distributed grid control with sub-cyclic local response capability|
    US10218175B2|2016-02-11|2019-02-26|Smart Wires Inc.|Dynamic and integrated control of total power system using distributed impedance injection modules and actuator devices within and at the edge of the power grid|
    US10651633B2|2016-04-22|2020-05-12|Smart Wires Inc.|Modular, space-efficient structures mounting multiple electrical devices|
    US10931140B2|2016-05-05|2021-02-23|Onesubsea Ip Uk Limited|Supply of auxiliary power to remote installations|
    US10468880B2|2016-11-15|2019-11-05|Smart Wires Inc.|Systems and methods for voltage regulation using split-conductors with loop current reduction|
    US10468944B2|2017-01-25|2019-11-05|General Electric Company|System and method for synchronous condensing|
    US10666038B2|2017-06-30|2020-05-26|Smart Wires Inc.|Modular FACTS devices with external fault current protection|
    NO20190801A1|2019-06-26|2020-12-28|Fsubsea As|System for subsea pressure booster power supply and distribution|
    GB2596568A|2020-07-01|2022-01-05|Impaq Tech Limited|Subsea power unit|
    法律状态:
    2018-12-26| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2019-07-16| B25D| Requested change of name of applicant approved|Owner name: AKER SOLUTIONS AS (NO) |
    2019-08-06| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2020-02-04| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2020-03-24| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 13/09/2011, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    NO20101276|2010-09-13|
    NO20101276|2010-09-13|
    PCT/EP2011/065797|WO2012034984A2|2010-09-13|2011-09-13|Stable subsea electric power transmission to run subsea high speed motors|
    [返回顶部]