• 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:
    The invention relates to a device (50) for limiting an electrical current in an electrical conductor of an electrical installation. The device (50) comprises a receiving unit adapted to receive a measurement of the electrical current in the electrical conductor, and further comprising a limiting unit adapted to limit said electrical current when the measured electrical current reaches a threshold. The device (50) is distinguished by comprising an obtaining unit adapted to obtain electrical energy from a second electrical conductor, wherein the limiting unit is adapted to inject said obtained electrical energy as an electrical current into the first electrical conductor, whereby the injected electrical current constitutes a replacement for at least a part of the first electrical current, which first electrical current is thereby limited. The invention also relates to an electrical system and a method for limiting an electrical current in an electrical conductor of an electrical installation.
    公开号:SE1001007A1
    申请号:SE1001007
    申请日:2010-10-12
    公开日:2012-04-13
    发明作者:Bjoern Jernstroem
    申请人:Ferroamp Elektronik Ab；
    IPC主号:
    专利说明:

    The statistical distribution of the phase currents in a typical detached house.
    As can be read in the figure, the current in the three phase conductors is below 16 A 99% of the time, however, peak currents occur up to 25 A. The main fuses and supply cable must therefore have a minimum rated current of 25 A.
    There will thus be a compromise between choosing a main fuse with low rated current for cost reasons, but at the same time the rated current must be high enough to avoid the fuse tripping at peak loads.
    A solution to this problem can be achieved with power guards.
    Power monitors limit the phase currents by measuring the phase currents and disconnecting preselected loads if the phase currents exceed the rated current of the main fuses. This is described, for example, in SE 515 272 and CH 641 295.
    Disadvantages of these methods are that the disconnected load cannot be used while it is disconnected, in addition, the load to be disconnected must be a three-phase load or load connected to the same phase which currently exceeds the rated current of the main fuse. In many households / small industries there are not many three-phase loads that can be disconnected without problems. Furthermore, many loads are connected via electrical outlets and movable. Traditional power monitors only work with permanently installed loads.
    Furthermore, modern single-family homes / industries receive more and more single-phase loads, as manufacturers of electrical equipment only install three-phase connections on the most power-intensive appliances. 10 15 20 25 30 Many products are available on the market to limit the phase currents to the rated current of the main fuses.
    All work by: a) Disconnecting preselected loads at load peaks as described above. The load is disconnected by means of electromechanical relays to avoid that the rated current of the main fuse is exceeded. Figure 2 schematically shows such a system. Relays 22 are used to limit or disconnect loads 16, 17 when any phase current exceeds the rated current of the main fuse. or b) Moving a load from one phase to another This is described, for example, in US 5,181,180 Munro, and in US 7,242,110 Matsumoto et al. These references describe how relays are used to disconnect or move loads between the phase conductors. Figure 3 schematically shows such a system.
    Relays 22 are used to move loads 17 from one phase conductor to another when a phase current exceeds the rated current of the main fuse.
    Both of these methods solve the problem of overloading the phase conductors, but also have some disadvantages. For example, when a load is moved between the phase conductors, transients arise due to the phase difference between the phase conductors. Such transients can cause problems in sensitive electronic equipment.
    Furthermore, the system must be aware of which loads can be moved or disconnected. This requires careful planning to select loads for disconnection and loads may need to be manually connected to different phases to balance the load. Despite this (often labor-intensive) planning of the electrical installation, the function will be deficient in systems with many portable loads, since the size and location of such loads can not be foreseen and thus not taken into account. As before, it also applies that a disconnected load can of course not be used while it is disconnected.
    Summary of the Invention The present invention solves or reduces the problems of the prior art. The invention is thus an alternative device for limiting the current in an electrical conductor.
    According to the invention, this is achieved with a device having the features of claim 1.
    By abandoning the traditional technique of devices for limiting phase currents from electromechanical relays for disconnecting loads to the transmission of electrical energy between electrical conductors by injecting current, several advantages can be achieved. First, if there is space in an electrical conductor, for example one of the phase conductors in a three-phase installation, then energy can be transferred from this phase conductor to another phase conductor where the current needs to be limited. This avoids the problem that a load on the overloaded phase conductor needs to be disconnected. Furthermore, the problem of planning and selecting loads for disconnection is avoided. There is no longer any need for labor-intensive load planning / selection when installing an electrical system. Furthermore, since the device does not need to be active (does not need to acquire or inject electrical energy) when no current is on or exceeds a threshold value, the device can be made very energy efficient in this state because it only needs to monitor the phase currents to see if any threshold value 20 25 30 is exceeded. In addition, the previous disadvantage that it was difficult to predict to which electrical conductor a portable single-phase load is connected and thus where disconnection of such a load can take place in an electrical installation is also avoided because a device according to the invention automatically takes such loads into account. Furthermore, prior devices of current limiting equipment which can move loads by means of relays from one electrical conductor to another are also improved in the sense that transfer according to the prior art can only be performed for whole loads and not parts of a load.
    A device according to the invention transfers any (within the rated power of the device) amount of energy between electrical conductors. Ie. the device enables an almost stepless transfer of energy between different conductors, which corresponds to a device according to the prior art could transfer a part of a load between different conductors (they cannot). Ie. according to the invention, all available electrical power in the electrical conductors can always be used when needed. According to the prior art, situations may arise where a load which is desirable to be moved to another conductor cannot be moved because the conductor to which the load is to be moved cannot accommodate the entire load within the available space.
    The invention also relates to an electrical system and a method for limiting an electrical current in an electrical conductor with the advantages that can be achieved with the device.
    Additional realizations are announced in the dependent requirements.
    List of figures Realizations exemplifying the invention are described in the figures, where: Figure 1 schematically shows an electrical installation, Figure 15 schematically shows an electrical installation with a current limiter based on disconnection of load according to prior art, Figure 3 shows an electrical installation with current limiter based on movement of loads according to prior art, Figure 4 shows an electrical installation with a current limiter according to the invention, Figure 5 shows schematically a realization of a current limiter, Figure 6 shows an example of the distribution of phase currents over time in an electrical installation, Figure 7 shows an example of the phase currents as a function of time in an electrical installation, Figure 8 shows the acquisition and injection of electrical currents from different electrical conductors in an electrical installation, Figure 9 shows a realization of a current limiter which includes an unconnected energy source, Figure 10 shows a realization of a current limit nsare consisting of a separate procurement and limitation unit.
    Detailed Description of the Invention A basic variant of a device 50 according to the invention for limiting a (first) electric current in a (first) electrical conductor of an electrical installation will now be described. An example of such a device 50 connected to an electrical installation is shown in Figure 4.
    The device 50 comprises a receiver unit 59 arranged to receive a measurement of the (first) electric current in the (first) electric conductor. The receiver unit 59 may either communicate with an external measurement sensor or may include an integrated measurement sensor that communicates measurements to the receiver unit 59. In Figure 4, the measurement sensor is integrated in the device 50 and is connected to current sensors 21 to measure a current in an electrical leader. In this context, it is understood that measurement of current may involve direct or indirect measurement. Ie. either the current in question can be measured directly or it can be measured indirectly by measuring all other currents into a connection point, after which the current can be calculated with Kirchoff's current law and thus be said to be measured indirectly. Furthermore, the device comprises a limiting unit 60 arranged to limit said electric current when the measured (first) electric current reaches a (first) threshold value. How this is achieved is described below.
    In order to be able to limit an electric current according to the invention, the device 50 also comprises a procurement unit 61 arranged to procure electrical energy from a second electrical conductor, i.e. from an electrical conductor other than the one in which a current is to be limited. By way of example, reference is made to Figure 4 where the device 50 is connected to three different conductors 101, 102, 103 via three connection conductors 111, 112, 113. If, for example, conductor 101 is measured, with the current sensor 21, to conduct a current which has reached a threshold value at which the current is to be limited, the procurement unit in the device 50 can use one of the other, in this case, two conductors 102, 103 to procure energy from. Specific examples of how electrical energy is procured follow below.
    Once electrical energy has been obtained from a conductor, the energy can be injected into the overloaded (first) conductor. For this purpose, the limiting unit 60 is arranged to inject said acquired electrical energy as an electrical current into the first electrical conductor. Wherein the injected electric current constitutes a replacement for at least a part of the first electric current, which first electric current is thereby limited. As an example according to Figure 4, electrical energy can be obtained from conductor 102 via the connection conductor 112 and then injected into conductor 101 via the connection conductor 111. If the current / energy flowing to a load via the control panel 12 is the same before and after injection, ie the load and mains voltage are unchanged , this means that the current from source L1 must be lower after the injection, since an additional current has been injected closer to the load and the sum of these currents must be equal to the current to the load according to Kirchoff's current law.
    To further illustrate the substance, see Figure 8. In the example of Figure 8, the current from phase L2 of 16 A is limited by injecting a current from the device 50. Together they result in a current of 24 A to the load 3. Ie if the current from L2 had not been supplemented with the injected current, load 3 would have drawn 24 A from L2. In this case, the current has been limited to 16 A by injection.
    Furthermore, with reference to Figure 10, it is understood that the acquisition unit 61 and the limitation unit 60 may be two physical units, but this function may also be realized with a combined acquisition and limitation unit, which will be described later with reference to Figure 5.
    To realize both the acquisition and injection of electrical energy, several different principles can be used. For example, switched voltage converters can function both as a procurement and limitation unit for acquiring and injecting electrical energy by quickly chopping up voltage / current in the various conductors. The principle of such switched converters is well known to a person skilled in the art. 10 15 20 25 30 However, other principles are also conceivable, such as rotary transducers consisting of motor / generator and controllable torque connections. Furthermore, phase transducers with transformers can also be used to realize the invention.
    It should be mentioned that since electricity networks are supplied by voltage sources, electrical current and power are proportional and connected to each other. That is, it is not possible to inject / obtain electric current without injecting / obtaining electrical power and vice versa. That is, limiting an electric current in a conductor is analogous to limiting the power in said conductor and measuring a current is analogous to measuring an effect.
    For an insight into a possible scenario for the available electrical energy in an electrical installation, see Figure 7.
    It gives an example of a measurement of the phase currents as a function of time, here there are current peaks of up to 30 A in L1, at the same time the currents in L2 and L3 are significantly lower.
    Figure 7 also shows the theoretical value with current peaks up to 19 A, to which the currents could be limited by moving energy between the phase conductors according to the invention.
    In an embodiment of a device according to the invention, the procurement unit can be arranged to procure electrical energy also from at least one further electrical conductor. As from both conductors 102 and 103 in Figure 4. This is advantageous because energy can be obtained from either of these conductors 102, 103 or from both at the same time. If one of the conductors is already overloaded, the other can be used instead of providing energy for injection, or both can be used to provide some of the required energy. In a general case with N conductors, all N conductors can be arranged for the acquisition of electrical energy, and at any given time, N minus the number of conductors into which energy is injected can be used simultaneously for the acquisition of electrical energy.
    A further embodiment of any previous embodiment of the device 50 according to the invention comprises that the receiving unit is arranged to receive a further measurement of a further electric current which is to be limited in at least one further electric conductor. Again referring to the example in Figure 4, this means that the device 50 would be arranged to measure a current also in at least one further electrical conductor, for example the conductors 101 and 102. Further in this embodiment the limiting unit would be arranged to inject said acquired electrical energy as an electric current also in the further at least one electric conductor when the further measured current in this conductor reaches a second threshold value.
    The functionality of the previous embodiments of the device, to limit the current in one conductor by injecting another current into this conductor is now shown for further conductors. That is, in Figure 4, two or even all conductors 101, 102, 103 can be monitored and electrical energy injected when needed. Note that there is no inherent contradiction in the fact that the conductors can potentially be injected with energy, to coincide with or be the same as that the conductors can potentially be used for acquisition. That is, in the example of Figure 4, all conductors 101, 102, 103 would simultaneously function as potential sources of electrical energy (electrical energy is procured from these) and as potential recipients of energy (energy is injected into them). The important thing is that energy is only injected into a conductor if the current in this conductor has reached a threshold value. As soon as the current in this conductor falls below the threshold value, this conductor becomes a candidate to be an energy source for another conductor in the electrical installation.
    A further embodiment of any previous embodiment of the device according to the invention comprises that the procurement unit is arranged so that at least one conductor to procure electrical energy from is connectable to a non-mains-connected energy source. By non-connected energy source is meant here an electrical energy source whose energy is not distributed to the device via the public electricity grid. This can be something of a battery, a wind turbine, a solar panel. That is, the procurement unit may have connections intended for such energy sources and may therefore also be arranged to take care of different voltages and current characteristics of such non-connected energy sources compared with that of the public electricity network. An advantage of this embodiment is that in the event of a total deficit of electrical energy in the conductors connected to the mains, given the need, the non-mains connected source can help to supplement this need and thus avoid tripping a fuse. An example of such a non-mains energy source is shown in Figure 9, which depicts a battery 2.
    A further advantage is that a current-limiting device realized with a switched voltage converter only needs to have additional components to enable the transmission of electrical energy from a non-connected source to the mains.
    According to a further embodiment of any previous embodiment of the device according to the invention, the receiving unit may be arranged to receive a measurement of an electric current in any electrical conductor to procure electrical energy from and wherein the procuring unit is arranged to procure electrical energy from any such conductor. electrical conductor when the measured electrical current in a specific such conductor is below a third threshold value. That is, this threshold value for when electrical energy can be procured does not necessarily have to be the same as the threshold value for when electrical energy can be injected, thus giving a little extra freedom for the implementation. Of course, the thresholds can be the same if desired.
    The device may also comprise a storage element for electrical energy in which the device is arranged to store said electrical energy after acquisition and before injection. In this way, energy can be available for injection even at a moment when no energy is available for acquisition. For example, in an AC system, the storage element can be used to bridge the differences in phase position between different conductors, and reduce interference that might otherwise potentially occur when injecting electrical energy. Such storage elements are shown as capacitors 52 in the embodiment of Figure 5.
    In an embodiment of device according to the invention where the total number of conductors from which energy can be obtained or injected, which are not connected to an unconnected energy source, are three and constitute three different AC conductors in a three-phase electrical installation. This is the case with the embodiments of the device 50 shown in Figures 4, 5, 8, 9 and 10. The device 50 is thus arranged for connection to a three-phase system, which is a common distribution system in many countries. A further embodiment of any previous embodiment of the device according to the invention comprises that the acquisition unit and the limiting unit are arranged to acquire and inject electrical energy in such a way as to at least also reduce any harmonics in the electrical conductor in which electrical energy is injected. This can be achieved by measuring the current harmonics in the conductor with the current sensors 21 and injecting a current with the same amplitude but with a 180 ° phase difference and thereby compensating for the current harmonic in the conductor. In addition, it should be mentioned that the reduction of harmonics generally requires both the acquisition and injection of electrical energy since the harmonic current flows in both directions during a half period of the voltage.
    Therefore, the acquisition unit and the constraint unit must be used together to reduce harmonics.
    A further embodiment of any previous embodiment of the device comprises that the procurement unit and the limiting unit are arranged to procure and inject electrical energy in such a way as to at least also correct a power factor less than 1 in the electrical conductor in which electrical energy is injected. The principle for this is similar to the principle for reduction of harmonics as described above.
    This is also true in the sense that the acquisition of energy can also be performed to correct the power factor.
    In the event of a power failure in any electrical conductor in which the device is arranged to inject electrical energy, the limiting unit is arranged to inject said electrical energy into such an electrical conductor. For example, if a phase for some reason fails in a three-phase system, the device can keep this phase live in the electrical installation even if no current is supplied from the mains. 10 15 20 25 30 14 A situation can arise when all the electrical current space in the conductors available for the acquisition of electrical energy is used for injection into another conductor. In such a situation, overload, and the risk of tripping a fuse, can be avoided by the device comprising a disconnection unit arranged to disconnect at least one load connected to any electrical conductor in which the device is arranged to inject electrical energy. Such a disconnection unit would thus be activated if the available electrical energy for injection is not sufficient to limit the electrical current in such an electrical conductor to or below a threshold value for said electrical current.
    It should be noted that, although not explicitly mentioned, the acquisition unit and the limitation unit are arranged to refrain from acquiring or injecting electrical energy when all electrical currents to be limited by the device are below the threshold values for each such electrical current. Since the limiting unit of the device will only limit a current by injection when such a current has reached a threshold value, it is understood that no such limitation occurs when no current has reached the threshold value for limiting this current. Thus, in this case, the device will only passively monitor the currents. This has the advantage that the losses associated with the acquisition and limitation of currents are avoided, which results in low self-consumption of the device in this operating mode.
    Some of the current threshold values of the device may be varied.
    For example, the device may be arranged to vary the threshold values by any of: time and current in the electrical conductors. An advantage of this is that the connection cables or main fuses can allow a shorter overload. If threshold values are set higher for short-term current peaks, no energy is transferred between the conductors and consequently no power loss occurs in the device.
    The device according to the invention can be included in many different electrical systems. Such electrical systems including a device 50 according to the invention may include electrical systems in residential buildings, electrical systems that supply industrial processes and electrical systems in electrical equipment.
    Example of an embodiment of a device according to the invention With reference to Figure 5, a possible realization of device according to the invention will now be described. This is only an example and a person skilled in the art could design many other alternatives from the basic principles of the device described above.
    In this realization, the limiting unit and the procurement unit are combined into a unit 62, which comprises three half-bridges, each consisting of two IGBT transistors 51 with a fast diode. (An alternative implementation with separate half-bridges for the limitation unit and separate half-bridges for the procurement unit is of course also conceivable). Another alternative could be to realize the procurement unit with a "Vienna rectifier" as described in EPO660498). . The control unit 55 further uses pulse width modulation (PWM) on the drive pulses to control the current absorbed or injected into a phase conductor. Two different control loops for pulse width modulation are used; a first loop controls the rms value current (RMS) absorbed or injected into each phase conductor, a second loop synchronizes the instantaneous current with the instantaneous mains voltage in each phase so that the current is absorbed or injected by the power factor one.
    The control unit receives measurements of the phase currents through a receiving unit 59 which can be either an analog interface to current transformers or current sensors, but also a digital interface to an external sensor, for example the sensors used in the electricity meter in the electrical installation. The receiving unit 59 further receives signals from internal current sensors 58 which are used as feedback signals in the PWM loop in the control unit for how much current is actually absorbed or injected.
    The control unit also receives measurements of the mains voltage from the receiving unit 59 which measures the mains voltage in the nodes 63.
    The measurement can either be made directly by the receiving unit shown in Figure 5, but also by voltage transformers or external sensors. The control unit needs voltage information from each phase conductor to be able to correctly control the IGBT transistors for injection or acquisition of electrical energy.
    When one of the half-bridges injects current into a phase conductor, the drive pulses are synchronized so that the upper transistor conducts when the phase voltage is positive and the lower transistor conducts when the phase voltage is negative. The pulse width is regulated proportionally to the instantaneous output current. Thereby, energy is taken from the internal energy storage capacitor 52. The conductive transistor together with the switch inductor 53 acts as a Buck converter. When current is to be absorbed, the control is reversed so that the positive transistor conducts when the phase voltage is negative and vice versa. The conductive transistor together with the switch inductance and the diode in the opposite transistor now function as a Boost converter.
    Method according to the invention The invention also comprises a method for limiting a (first) electric current in a (first) electrical conductor of an electrical installation. Different embodiments of the method correspond to different embodiments of the device and entail corresponding advantages. The procedure will be briefly specified below.
    The method comprises: - measuring the (first) electric current in the (first) electrical conductor, - limiting said electric current when the measured (first) electric current reaches a (first) threshold value, - obtaining electrical energy from a second electrical conductor, and limiting said first electric current by: - injecting said acquired electric energy as an electric current into the first electric conductor, the injected electric current constituting a replacement for at least a part of the first electric current, which first electric current is thereby limited .
    An embodiment of the method further comprises procuring electrical energy from at least one additional electrical conductor.
    In an embodiment of any previous embodiment, the method further comprises receiving a further measurement of a further current to be limited in a further at least one electrical conductor, and injecting said electrical energy as an electric current also into the further at least one electrical conductor when the additional measured current in this conductor reaches a second threshold.
    In an embodiment of any previous embodiment, the method further comprises procuring electrical energy from at least one conductor connected to a non-mains connected energy source such as: a battery, a wind turbine, a solar panel.
    In an embodiment of any previous embodiment, the method further comprises - measuring an electric current in an electrical conductor from which electrical energy is to be obtained and wherein the step of acquiring electrical energy from such a conductor is performed when the measured current of a specific such conductor is below a third threshold.
    In an embodiment of any previous embodiment, the method further comprises that after said electrical energy is acquired, it is stored before said injection of said electrical energy.
    In an embodiment of any previous embodiment, the method further comprises that the total number of conductors from which electrical energy can be obtained or injected, and which are not connected to an unconnected energy source, are three and constitute three different AC conductors in a three-phase electrical installation. In an embodiment of any previous embodiment, the method further comprises that said acquisition and injection of electrical energy is carried out so as to also at least reduce any harmonics in the electrical conductor in which electrical energy is injected.
    In an embodiment of any previous embodiment, the method further comprises that said acquisition and injection of electrical energy is carried out so that also a power factor less than 1 is corrected in the electrical conductor in which electrical energy is injected.
    In an embodiment of any previous embodiment, the method further comprises in the event of a power failure in any electrical conductor into which electrical energy may be injected, injecting said electrical energy into such a conductor.
    In an embodiment of any previous embodiment, the method further comprises disconnecting at least one load connected to any electrical conductor into which electrical energy may be injected if the available electrical energy for injection is not sufficient to limit the current in such electrical conductor to or below a threshold value for this electric current.
    In an embodiment of any previous embodiment, the method further comprises refraining from acquiring or injecting electrical energy when all electrical currents to be limited are below the threshold values for each such current. In an embodiment of any previous embodiment, the method further comprises varying the current threshold values of the method as a function of time or current. 10 15 20 25 30 21 Legend 1. Three-phase energy source 2. Unconnected energy source 3. Asymmetric three-phase load 10. Electrical installation 11. Main fuses 12. Group control unit 13. Group fuses 14. Outlets 15. Outlet-connected (portable) load 16. Fixed installed three-phase load 17. Fixed-phase single-phase load 20. Power monitor 21. Current transformers / current sensors 22. Relays / contactors 30. Load switches 50. Current limiter 51. IGBT transistor 52. Condenser in DC voltage intermediate 53. Switch inductances 54. EMC filter 55. Control unit 56. Diode 57. Boost inductance 58. Current transformers / current sensors 59. Receiving unit 60. Limiting unit 61. Procurement unit 62. Combined limiting and procurement unit 63. Node for voltage measurement 101, 102, 103. Electrical conductors 111, 112, 113. Connection conductors
    权利要求:
    Claims (15)
    [1]
    A device (50) for limiting a (first) electric current in a (first) electrical conductor of an electrical installation, the device (50) comprising a receiver unit (59) arranged to receive a measurement of the (first) electric current in the (first) electrical conductor, and further comprising a limiting unit (60) arranged to limit said electric current when the measured (first) electric current reaches a (first) threshold value, characterized in that comprising a procurement unit (61) arranged to procure electrical energy from a second electrical conductor, and wherein the limiting unit (60) is arranged to inject said acquired electrical energy as an electrical current into the first electrical conductor, the injected electrical current constituting a replacement for at least a part of the first electrical current, which first electric current is thereby limited.
    [2]
    Device (50) according to claim 1, wherein the procurement unit (61) is arranged to procure electrical energy also from at least one further electrical conductor.
    [3]
    The device (50) according to claim 1 or 2, wherein the receiving unit (59) is arranged to receive a further measurement of an additional electric current to be limited in at least one further electrical conductor, and wherein the limiting unit (60) is arranged to inject said acquired electrical energy as an electrical current also in the additional at least one electrical conductor when the additional measured current in this conductor reaches a second threshold value. 10 15 20 25 30 23
    [4]
    Device (50) according to any one of claims 1-3, wherein the procurement unit (61) is arranged so that at least one conductor to procure electrical energy from is connectable to a non-mains-connected energy source (2), such as a battery, a wind turbine, a solar panel.
    [5]
    A device (50) according to any one of claims 1-4, wherein the receiving unit (59) is arranged to receive a measurement of an electric current in some electrical conductor to procure electrical energy from and wherein the procuring unit (61) is arranged to procure electrical energy from any such electrical conductor when the measured electric current in a specific such conductor is below a third threshold value.
    [6]
    A device (50) according to any one of claims 1-5, comprising a storage element for electrical energy (52) in which the device (50) is arranged to store said electrical energy after acquisition and before injection.
    [7]
    Device (50) according to any one of claims 1-6, wherein the total number of conductors from which electrical energy can be obtained or injected, which are not connected to an unconnected energy source, are three and constitute three different AC conductors in a three-phase electrical installation. .
    [8]
    A device (50) according to any one of claims 1-7, wherein the acquisition unit (61) and the limiting unit (60) are arranged to acquire and inject electrical energy in such a way as to at least also reduce any harmonics in the electrical conductor in which electrical energy is injected. .
    [9]
    A device (50) according to any one of claims 1-8, wherein the procuring unit (61) and the limiting unit (60) are arranged to procure and inject electrical energy in such a way as to also correct a power factor less than 1 in the electrical conductor into which electrical energy is injected.
    [10]
    A device (50) according to any one of claims 1-9, wherein in the event of a power failure in any electrical conductor in which the device (50) is arranged to inject electrical energy, the limiting unit (60) is arranged to inject said acquired electrical energy into a such electrical conductor.
    [11]
    The device (50) of any of claims 1-10, further comprising a disconnecting unit arranged to disconnect at least one load connected to any electrical conductor in which the device (50) is arranged to inject electrical energy if the available electrical energy for injection is not is sufficient to limit the electric current in any such electrical conductor to or below a threshold value for said electric current.
    [12]
    Device (50) according to any one of claims 1-11, wherein the procurement unit (61) and the limiting unit (60) are arranged to refrain from acquiring and injecting electrical energy, respectively, when all electrical currents to be limited by the device (50) are below the threshold values. for each such electric current.
    [13]
    Device (50) according to any one of claims 1-12, wherein the device (50) is arranged to vary one of the current threshold values of the device (50) by any of: time and current in the electrical conductors.
    [14]
    An electrical system comprising a device (50) according to any one of claims 1-13. 10 15 20 25
    [15]
    A method of limiting a (first) electrical current in a (first) electrical conductor of an electrical installation, the method comprising: - measuring the (first) electrical current in the (first) electrical conductor, - limiting said electrical current when the measured (first) electric current reaches a (first) threshold value, characterized by: - obtaining electric energy from a second electric conductor, and limiting said first electric current by: - injecting said acquired electric energy as an electric current into the first electric conductor, the injected electric current being a replacement for at least a part of the first electric current, which first electric current is thereby limited.
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    同族专利:
    公开号 | 公开日
    PT2628228T|2016-10-13|
    EP2628228A4|2014-06-18|
    US20130314057A1|2013-11-28|
    EP2628228A1|2013-08-21|
    WO2012050501A1|2012-04-19|
    SE536410C2|2013-10-15|
    ES2589004T3|2016-11-08|
    EP2628228B1|2016-06-08|
    US9214813B2|2015-12-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    EP1672139A2|2001-09-20|2006-06-21|Välinge Innovation AB|Flooring with mechanically lockable quadrangular floorboards|
    EP2189590A2|2002-04-03|2010-05-26|Välinge Innovation AB|A method for separating two strips for floorboards and a method for forming a joint for floor elements|DE1513957B2|1965-09-22|1972-03-23|Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt|ARRANGEMENT FOR LOAD SYMMETRATION WITH THE HELP OF A REACTIVE CURRENT JUDGE|
    AT353895B|1977-09-16|1979-12-10|Neuelektrik Ag|CONTROL DEVICE FOR THE DISTRIBUTION OR CONNECTION OF ELECTRICITY CONSUMERS|
    US5181180A|1990-08-16|1993-01-19|Munro William A|Method and apparatus for monitoring and maintaining an optimum balance between the main phases of a multi-phase multiple load local electrical distribution system|
    US5309346A|1991-09-16|1994-05-03|Westinghouse Electric Corp.|Transmission line fault current dynamic inverter control|
    AT406434B|1993-12-23|2000-05-25|Ixys Semiconductor Gmbh|DEVICE FOR FORMING A THREE-PHASE VOLTAGE SYSTEM INTO A PREDIBLE DC VOLTAGE SUPPLYING A CONSUMER|
    SE515272C2|1995-05-22|2001-07-09|Ove Vilhelm Erik Nilsson|System for controlling electrical power fed to outlet connected to mains|
    JP4078217B2|2003-01-27|2008-04-23|関西電力株式会社|Power system protection device|
    JP3863123B2|2003-04-04|2006-12-27|三菱電機株式会社|3-phase circuit load unbalance elimination control system|
    US7920392B2|2007-05-11|2011-04-05|Soft Switching Technologies Corporation|Dynamic voltage sag correction|WO2015158386A1|2014-04-17|2015-10-22|Abb Technology Ltd|Energy storage for balancing phases in a microgrid|
    DE102016108394A1|2016-05-06|2017-11-09|Wobben Properties Gmbh|Method for compensating feed-in currents of a wind farm|
    CN108134400B|2017-11-29|2021-01-26|国网浙江省电力公司泰顺县供电公司|Treatment method and device for three-phase unbalance|
    EP3782849A3|2019-08-13|2021-03-03|Zaptec IP AS|A dc charging device for an electric vehicle and for providing power management of a connected grid|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    SE1001007A|SE536410C2|2010-10-12|2010-10-12|Device for limiting an electric current|SE1001007A| SE536410C2|2010-10-12|2010-10-12|Device for limiting an electric current|
    US13/261,631| US9214813B2|2010-10-12|2011-10-11|Device and method for limiting an electrical current|
    ES11832829.3T| ES2589004T3|2010-10-12|2011-10-11|Device and method to limit an electric current|
    PT118328293T| PT2628228T|2010-10-12|2011-10-11|Device and method for limiting an electrical current|
    EP11832829.3A| EP2628228B1|2010-10-12|2011-10-11|Device and method for limiting an electrical current|
    PCT/SE2011/000180| WO2012050501A1|2010-10-12|2011-10-11|Device and method for limiting an electrical current|
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