• 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:
    ABSTRACT An electric system in a motor vehicle (1) comprises a battery assembly (2) with two batteries (3, 4). A generator (5) generates a three-phase voltage and has three phase windings (6-8) with first ends (9-11) connected to each other by a star connection in a star point (12). A rectifier (22) has three phase legs (19-21) having each at least two rectifying members (23-28) connected in series. Second ends of each winding opposite to the star point (12) are connected to a midpoint (16-18) of a phase leg each and opposite ends of each phase leg are connected to opposite ends (29, 30) of the battery assembly. First means (31, 32) is configured to enable connection of a consumer (33) of electric energy to tap a voltage across one (4) of the batteries. Second means (34) connects the star point (12) of the generator (5) to a midpoint (35) of the series connection of batteries dividing the series connection into two equal parts.
    公开号:SE1451073A1
    申请号:SE1451073
    申请日:2014-09-15
    公开日:2016-03-16
    发明作者:Jan Hellgren
    申请人:Scania Cv Ab；
    IPC主号:
    专利说明:

    1 AN ELECTRIC SYSTEM FOR A MOTOR VEHICLE TECHNICAL FIELD OF THE INVENTION The present invention relates to an electric system configured to be arranged in a motor vehicle and comprising a battery assembly with a series connection of at least two power batteries, a generator configured to generate electric energy in the form of a three-phase voltage and having three phase windings with first ends connected to each other by a star connection in a star point, a three-phase rectifier with three phase legs having each at least two rectifying members connected in series, second ends of each winding opposite to said star point being connected to a midpoint of a phase leg each and opposite ends of each phase leg being connected to opposite ends of said series connection of batteries of said battery assembly, and • first means configured to enable connection of a consumer of electric energy to tap a voltage across one said end of said series connection of batteries and a midpoint thereof dividing this series connection into two equal parts.
    The power batteries of the battery assembly will function as service batteries used to assist said generator to feed consumers of electric energy.
    The invention is not restricted to any special type of motor vehicles, although the invention is particularly applicable to utility 2 vehicles, especially wheeled utility vehicles, such as trucks or lorries and buses, and the invention will for that sake hereinafter primarily be discussed for that field of use for illuminating the invention but accordingly not in any way restrict it thereto.
    Such utility motor vehicles have typically an electric system with a said battery assembly with a series connection of at least two power batteries, mostly two 12 V-batteries connected in series, or an operating voltage of 24 V obtained by a series connection of two battery banks with a plurality of 12 V-batteries connected in parallel. Especially in wheeled utility vehicles, such as trucks and buses, there is an increasing interest to use electronic equipment already developed and used in cars having an electric system with a 12 V operating voltage. This is the reason for providing an electric system for such vehicles with said first means enabling a connection of such electronic equipment to tap a voltage across one of said power batteries or one of said battery banks of said battery assembly for the use of such electronic equipment in a vehicle having an operating voltage being twice the operating voltage of said electronic equipment.
    However, a connection of one or more such consumers of electric energy to tap said voltage and by that electric energy from one part of the battery assembly, such as one of the batteries thereof, will result in an unbalance of the charging of the batteries, which means that the battery from which electric energy is tapped will be discharged and the voltage thereacross will decrease. The voltage across the other battery will then increase correspondingly resulting in a risk of overcharging thereof. 3 BACKGROUND ART It is known try to solve the problem of said charging unbalance by providing an electric system of the type defined in the introduction with an electronic equalizer measuring the voltage across a battery from which a voltage is tapped by said first means and which takes energy from the entire battery assembly and transform it to the battery last mentioned so that this gets the same charging degree as the other battery of the battery assembly. An electric system for a motor vehicle provided with such an equalizer is known through WO 84/01475. However, such an electronic equalizer is rather costly and the function thereof has to rely upon sensitive electronic components resulting in a not insignificant risk of failure.
    SUMMARY OF THE INVENTION The object of the present invention is to provide an electric system of the type defined in the introduction being improved in 20 at least some aspect with respect to such electric systems already known.
    This object is obtained by providing such an electric system with the features listed in the characterizing part of appended patent claim 1.
    Connecting the star point of the generator to said midpoint of said series connection of batteries gives the generator the additional function as a said equalizer, since each of the two parts of the battery assembly will be charged separately through 4 the rectifying members connected to the same end of the series connection of the batteries as said part. A current will then flow in said second means between said star point and the midpoint of the series connection of batteries if that is needed for counter- acting any charging unbalance of said two parts. Thus, no such current will flow in the case of an existence of charging balance. Thus, no costly equalizer with sensitive electronic components is needed for obtaining charging balance, since the very operation principle of the generator will automatically act to obtain such balance. Said second means may easily be obtained by the application of a suitable connecting member to said star point of the generator and a cable connecting that member to a connecting member on said midpoint of the series connection of batteries.
    According to an embodiment of the invention each said part of the battery assembly comprises at least one battery with a rated voltage of 12 V, which is normally the case in wheeled utility vehicles, such as trucks and buses.
    According to another embodiment of the invention opposite electrodes of a said battery with a rated voltage of 12 V are connected to said midpoint and one said end of said series connection of batteries, respectively. This means that the rated voltage of the battery assembly will be 24 V as normally the case in said utility vehicles.
    According to another embodiment of the invention said first means is configured to enable connection of a consumer of electric energy to tap a voltage across each of said ends of said series connection of batteries and a said midpoint. This possibility to tap electric energy to consumers operating at a voltage being half the voltage of said battery assembly from both parts of said series connection of batteries will itself act against a charging unbalance of the two parts of the battery assembly, which is advantageous. However, the equalizer operation of the generator is still needed for obtaining the balance aimed at independently of how much electric energy is for the moment tapped from each of said parts of the battery assembly.
    According to another embodiment of the invention the electric system comprises a unit configured to control said generator so as to keep a sum of a current from said star point of the generator to said midpoint of said series connection of batteries and from said second end of said windings to said battery assembly below a predetermined maximum value to be handled by said rectifying members and/or generator. This ensures that said rectifying members and/or generator will not be exerted to a current being that high that they will be destroyed even if rather much electric energy is tapped from a said part in a short time calling for a high charging balancing current in said second means. This also means that the rectifying members and the generator have not to be over-dimensioned for being able to take an excessively high current in extreme situations.
    According to another embodiment of the invention said rectifying members comprise rectifying elements in the form of diodes. Rectifying diodes are presently the simplest and less costly way to realize said rectifying members, although other types of 6 rectifying members, such as thyristors, are conceivable within the scope of the invention.
    According to another embodiment of the invention each rectifying member comprises two or more rectifying elements connected in parallel and/or two or more rectifying elements connected in series. Parallel connection of rectifying elements in said rectifying member may be used for obtaining a sufficient current handling capacity thereof, whereas a series connection may be used for obtaining a sufficient voltage handling capacity thereof.
    According to another embodiment of the invention each part of said series connection of batteries comprises a battery bank of two or more batteries connected in parallel, and according to another embodiment of the invention each said part of said series connection of batteries comprises a battery bank of two or more batteries connected in series. Thus, in an electric system according to the present invention both said parts of the battery assembly have to be equal, but each part may be formed by only one battery or a plurality of batteries connected in parallel and/or series.
    The invention also relates to a motor vehicle provided with an electric system according to the invention.
    Other advantageous features as well as advantages of the present invention appear from the description following below. 7 BRIEF DESCRIPTION OF THE DRAWING With reference to the appended drawing, below follows a specific description of an embodiment of the invention cited as an 5 example.
    In the drawing: Fig 1illustrates very schematically an electric system according to an embodiment of the invention.
    DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION Fig 1 illustrates very schematically an electric system according to an embodiment of the invention and configured to be arranged in a motor vehicle 1, for example a truck. This electric system has a battery assembly 2 with a series connection of two power batteries 3, 4, which we here assume to have a rated voltage of 12 V. The electric system has also a generator 5 configured to generate electric energy in the form of a three-phase voltage and having three-phase windings 6-8 with first ends 9-11 connected to each other by a star connection in a star point 12. Second ends 13-15 of each winding opposite to said star point 12 are connected to a midpoint 16-18 of a phase leg 19-21 each of a three-phase rectifier 22 having two rectifying members in the form of diodes 23-28 connected in series in each phase leg 1921. Opposite ends of each phase leg are connected to opposite ends 29, 30 or poles of the battery assembly 2. 8 It is also illustrated how first means 31, 32 in the form of contact members are configured to enable connection of a consumer 33 of electric energy, such as an electronic equipment, to tap energy from one 4 of the batteries. An electric system having the features described so far is already known, and the new features defining the present invention will now be described.
    It is shown how the star point 12 of the generator is through a cable or line 34 connected to a midpoint 35 of the series connection of batteries of the battery assembly 2 dividing this series connection into two equal parts, in this case two 12 V-batteries. This feature means that if energy is tapped from the battery 4 to the consumer 33 a current 12 will flow from said star point 12 of the generator 5 to said midpoint 35 for obtaining balance of the charging of the two batteries 3, 4, so that a current Ii flows from the generator windings to the battery 3 and a current Ii + 12 to the battery 4 and then also through the diodes 24, 26, 28 connected to the negative pole 30 of the battery assembly. However, would there be a charging balance of the two batteries 3, 4 the current 12 would be zero.
    It is of importance that the sum of the currents Ii and 12 will not be above a predetermined maximum value to be taken by the diodes 24, 26 and 28 and the generator. A unit 36 configured to control the generator is therefore configured to do this while keeping said sum of these currents below said predetermined maximum value. Diodes having a higher rated current may possibly be selected for use as the diodes 24, 26, 28 than those used for the diodes 23, 25, 27, which only have to be able to together take the current Ii. 9 The connection 34 of the star point 12 of the generator with the midpoint 35 of the battery assembly will automatically give the generator the properties of an equalizer aiming to obtain charging balance of the two batteries 3, 4 of the battery assembly 2.
    The invention is of course not in any way restricted to the embodiment described above, but many possibilities to modifications thereof would be apparent to a person with ordinary skill in the art without departing from the scope of the invention as defined in the appended claims.
    Harmonic diodes not shown may also be connected between the 15 two poles 29, 30 for reducing harmonics created when generating the three-phase voltage by the generator.
    The rated voltage of each part of the battery assembly has not to be 12 V but may be any suitable for the electric system in the motor vehicle in question.
    权利要求:
    Claims (10)
    [1] 1. a generator (5) configured to generate electric energy in the form of a three-phase voltage and having three phase windings (6-8) with first ends (9-11) connected to each other by a star connection in a star point (12), 2. a three-phase rectifier (22) with three phase legs (19-21) having each at least two rectifying members (23-28) connected in series, second ends (13-15) of each winding opposite to said star point (12) being connected to a midpoint (16-18) of a phase leg each and opposite ends of each phase leg (19-21) being connected to opposite ends (29, 30) of said series connection of batteries (3, 4) of said battery assembly, and 3. first means (31, 32) configured to enable connection of a consumer of electric energy to tap a voltage across one said end of said series connection of batteries (3, 4) and a midpoint (35) thereof dividing this series connection into two equal parts, characterized in that it comprises second means (34) connecting said star point (12) of the generator (5) to said midpoint (35) of said series connection of batteries.
    [2] 2. An electric system according to claim 1, characterized in that each said part of the battery assembly (2) comprises at least one battery (3, 4) with a rated voltage of 12 V. 11
    [3] 3. An electric system according to claim 2, characterized in that opposite electrodes of a said battery (3, 4) with a rated voltage of 12 V are connected to said midpoint (35) and one said end (29, 30) of said series connection of batteries, respectively.
    [4] 4. An electric system according to any of the preceding claims, characterized in that said first means (31, 32) is configured to enable connection of a consumer of electric energy to tap a voltage across each of said ends (29, 30) of said series connection of batteries and a said midpoint (35).
    [5] 5. An electric system according to any of the preceding claims, characterized in that it comprises a unit (36) configured to control said generator (5) so as to keep a sum of a current (12) from said star point (12) of the generator to said midpoint (35) of said series connection of batteries and a current (11) from said second end (13-15) of said windings (6-8) to said battery assembly (2) below a predetermined maximum value to be handled by said rectifying members (23-28) and/or generator (5).
    [6] 6. An electric system according to any of the preceding claims, characterized in that said rectifying members comprises rectifying elements in the form of diodes (23-28).
    [7] 7. An electric system according to any of the preceding claims, characterized in that each rectifying member (23-28) comprises two or more rectifying elements connected in 12 parallel and/or two or more rectifying elements connected in series.
    [8] 8. An electric system according to any of the preceding claims, characterized in that each said part of said series connection of batteries (3, 4) comprises a battery bank of two or more batteries connected in parallel.
    [9] 9. An electric system according to any of the preceding claims, characterized in that each said part of said series connection of batteries (3, 4) comprises a battery bank of two or more batteries connected in series.
    [10] 10. A motor vehicle, especially a wheeled vehicle such as a truck or a bus, characterized in that it comprises an electric system according to any of claims 1-9. 11 LC GZ 5Z-E2. CZ-E. ZZ
    类似技术:
    公开号 | 公开日 | 专利标题
    US10693307B2|2020-06-23|Three phase charger accommodating wide input voltage range with flexible single phase input options
    US9312692B2|2016-04-12|System for charging an energy store, and method for operating the charging system
    JP6250683B2|2017-12-20|Car battery charging system
    US20150349687A1|2015-12-03|Electric Power Generation and Distribution for Islanded or Weakly-Connected Systems
    US9873341B2|2018-01-23|Transformerless, current-isolated onboard charger with solid-state switching controls
    JP2014520504A|2014-08-21|System and method for compensating an in-vehicle battery charger
    JP5939069B2|2016-06-22|Inverter
    EP3065260A1|2016-09-07|Ground power unit with lower noise and pollution emission
    Mackay et al.2014|DC ready devices-Is redimensioning of the rectification components necessary?
    EP2945246B1|2017-08-23|Voltage adjusting apparatus
    CN107820467B|2020-10-02|Vehicle-mounted charger and vehicle-mounted charging system
    JP6087531B2|2017-03-01|Power converter
    US7528505B2|2009-05-05|Systems and methods for balancing of DC link in three level PWM power conversion equipment
    JP5588774B2|2014-09-10|Protection device for power converter
    EP2765692A3|2015-09-30|An electrical system with an arrangement for filtering rectifier-generated 5th and 7th order current harmonics
    RU2552377C2|2015-06-10|Voltage balancer in three-phase network
    SE1451073A1|2016-03-16|An electric system for a motor vehicle
    US20150069859A1|2015-03-12|Photovoltaic inverter
    CN105048622B|2019-10-25|Three line transless ups systems and control are to reduce the method for common mode current
    US10742154B2|2020-08-11|Motor driving device
    JP6310790B2|2018-04-11|AC voltage converter
    WO2018060632A1|2018-04-05|Method for determining a current setpoint for a motor vehicle battery charger
    JP2017131022A|2017-07-27|DC high voltage generator
    JP5719827B2|2015-05-20|Power converter
    KR101442901B1|2014-09-23|Charging system for electronic vehicle and method for removing harmonic thereof
    同族专利:
    公开号 | 公开日
    SE538616C2|2016-10-04|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    SE1451073A|SE538616C2|2014-09-15|2014-09-15|An electric system for a motor vehicle|SE1451073A| SE538616C2|2014-09-15|2014-09-15|An electric system for a motor vehicle|
    [返回顶部]