JP2010252549A - System and method for charging and discharging of power between vehicles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power charging and discharging system capable of suppressing a high rush current from flowing between vehicles when the power is charged and discharged between the vehicles. <P>SOLUTION: Vehicles 1A and 1B include: connection connectors 13A, 13B connected to another vehicle via a power line; battery units 11A, 11B; first and second main relays 32a and 32b; and precharging relays 33 and precharging resistors 34 provided in parallel to the second main relays 32b, respectively. A power harness 2 is provided with a variable resistor device 3 having a relay and an external resistor in the inside. When the power harness 2 is connected to the vehicles 1A and 1B, the vehicles 1A and 1B each controls the first and second main relays 32a and 32b to bring the battery module 31 into a chargeable and dischargeable state, and the variable resistor device 3 controls the relay to cause the external resistor to pass a current, thereby controlling a rush current. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an inter-vehicle electric power discharging / charging system and an inter-vehicle electric power discharging / charging method for charging and discharging electric power to a power storage means mounted on a vehicle.

  2. Description of the Related Art Conventionally, a technique described in Patent Document 1 below is known as a technique for transferring power between vehicles. Patent Document 1 describes a method of charging electric power to a battery of the host vehicle by connecting the rescue vehicle and the battery of the host vehicle.

JP 2004-358304 A

  However, in the above-described technology, since the vehicles are directly connected, there is a possibility that an inrush current flows when charging of electric power is started. In particular, a scene that requires power transfer between vehicles is a state where the battery voltage of one vehicle is low and the battery voltage of the other vehicle is high. Therefore, a high inrush current may flow due to the potential difference between the batteries when the vehicles are connected to start power discharging.

  Therefore, the present invention has been proposed in view of the above-described circumstances, and an inter-vehicle power discharging / charging system and a vehicle that can prevent a high inrush current from flowing between the vehicles when discharging the electric power between the vehicles. An object is to provide a method for charging and discharging electric power.

  The present invention is an inter-vehicle power discharging / charging system that transfers power between vehicles, and is provided in a power harness that connects vehicles, and a resistance unit that suppresses a current flowing through the power harness, and an operation of the resistance unit External control means for controlling the power and a power discharging / charging device mounted on each vehicle. The power discharging / charging device is connected to a power discharging / charging device mounted on another vehicle via a power harness, a power storage device for storing power supplied to each part of the host vehicle, and connected to the power storage device. And a vehicle-mounted control means for controlling the opening / closing operation of the relay.

  In this inter-vehicle power discharging / charging system, when charging or discharging power to the power storage means, the vehicle-mounted control means controls the opening / closing operation of the relay, and the external control means changes the resistance value with respect to the current flowing through the power harness. Thus, the above-described problem is solved by controlling the operation of the resistance means.

  ADVANTAGE OF THE INVENTION According to this invention, when discharging electric power between vehicles, it can suppress that a high inrush current flows between vehicles by suppressing the energization current which flows into an electric power harness by the resistance means of a variable resistance apparatus.

1 is a circuit diagram showing a configuration of an inter-vehicle power discharging / charging system shown as an embodiment of the present invention. It is a circuit diagram which shows the structure of the variable resistance apparatus in the inter-vehicle electric power charging / discharging system shown as embodiment of this invention. It is a flowchart which shows the 1st battery charge operation | movement of the inter-vehicle electric power discharge system shown as embodiment of this invention. It is a figure which shows the change of an energization current when performing 1st battery charge operation | movement by the inter-vehicle electric power discharge / charge system shown as embodiment of this invention. It is a circuit diagram which shows the other structure of the variable resistance apparatus in the electric power discharge system between vehicles shown as embodiment of this invention. It is a flowchart which shows the 2nd battery charge operation | movement of the inter-vehicle electric power discharge system shown as embodiment of this invention. It is a figure which shows the change of an energization current when performing 2nd battery charge operation by the vehicle electric power discharge / charge system shown as embodiment of this invention. It is a circuit diagram which shows the other structure of the variable resistance apparatus in the electric power discharge system between vehicles shown as embodiment of this invention. It is a flowchart which shows the 3rd battery charge operation | movement of the inter-vehicle electric power discharge system shown as embodiment of this invention. It is a figure which shows the change of an energization current when performing 3rd battery charge operation by the inter-vehicle electric power discharge / charge system shown as embodiment of this invention. It is a circuit diagram which shows the other structure of the variable resistance apparatus in the electric power discharge system between vehicles shown as embodiment of this invention. It is a flowchart which shows the 4th battery charge operation | movement of the inter-vehicle electric power discharge charging system shown as embodiment of this invention. It is a figure which shows the change of an energization current when performing a 4th battery charge operation by the inter-vehicle electric power charging / discharging system shown as embodiment of this invention. It is a figure explaining the resistance change of the inter-vehicle electric power discharge system which performs 4th battery charge operation. It is a figure explaining the resistance change of the inter-vehicle electric power discharge system which performs 4th battery charge operation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Overall configuration of inter-vehicle power discharging / charging system]
As shown in FIG. 1, an inter-vehicle power discharging / charging system shown as an embodiment of the present invention is configured such that a vehicle 1 </ b> A and a vehicle 1 </ b> B are connected by an electric power harness 2 and exchange electric power. The power harness 2 is provided with a variable resistance device 3 including resistance means for suppressing a current flowing through the power harness 2 and external control means for controlling the operation of the resistance means.

  The vehicle 1A includes a battery device 11A, a DC / DC converter 12A, a connection connector portion 13A, and a control unit 14A. Similarly to the vehicle 1A, the vehicle 1B includes a battery device 11B, a DC / DC converter 12B, a connection connector portion 13B, and a control unit 14B. Note that the vehicle 1A and the vehicle 1B illustrated in FIG. 1 are electric vehicles that drive a driving motor, an air conditioner, and the like using the power of the battery module 31 included in the battery devices 11A and 11B, for example. In such vehicles 1A and 1B, control units 14A and 14B and battery devices 11A and 11B that perform a first battery charging operation and a second battery charging operation, which will be described later, in order to transfer power between the vehicles 1A and 1B. However, it constitutes a power discharge / charge device.

  The connection connector parts 13 </ b> A and 13 </ b> B are connection means connected to other vehicles via the power harness 2. The connection connector portions 13A and 13B include coupling portions 51a and 51b that are structured to be connected to the connector portions 21A and 21B at both ends of the power harness 2 by an operator. The connection connector portions 13A and 13B are connected to the connector portions 21A and 21B in order to be electrically connected to the positive and negative power lines 22, respectively.

  The battery devices 11A and 11B include a plurality of battery modules 31, a pair of first main relay 32a and second main relay 32b, a precharge relay 33, and a precharge resistor 34.

  The plurality of battery modules 31 are power storage means for storing power supplied to each part of the vehicle. The plurality of battery modules 31 can be switched in number, series state, or parallel state according to the amount of power required for the vehicle.

  A pair of power lines corresponding to the positive electrode and the negative electrode is connected to each of the positive electrode terminal and the negative electrode terminal of the battery module 31. A first main relay 32 a and a second main relay 32 b are connected to each of the pair of power lines in the battery module 31.

  The first main relay 32a and the second main relay 32b are provided on the power line corresponding to the positive electrode and the negative electrode in the battery device 11A. The first main relay 32a and the second main relay 32b are switched between a conductive state (closed state) and a cut-off state (open state) according to the control of the control units 14A and 14B.

  The second main relay 32b is provided with a precharge relay 33 and a precharge resistor 34 in parallel. The precharge relay 33 and the precharge resistor 34 are connected in series. Note that the precharge relay 33 and the precharge resistor 34 may be provided in parallel to the first main relay 32a. In this case, what is necessary is just to change the 1st main relay 32a and the 2nd main relay 32b in the battery charge operation mentioned later.

  The precharge relay 33 (auxiliary relay) is in a conductive state (closed state) and a cut-off state (open state) according to control of the control units 14A and 14B when power is exchanged between the vehicle 1A and the vehicle 1B. Can be switched between. When the precharge relay 33 is in a conducting state, a current for charging or discharging the battery module 31 flows through the precharge resistor 34 (inrush power suppression resistor). The precharge resistor 34 is configured so that the energization current does not exceed a threshold according to the total voltage of the battery module 31 and the energization current (inrush current) allowed when power is transferred between the vehicle 1A and the vehicle 1B. The resistance value is determined.

  The DC / DC converters 12A and 12B convert a DC voltage corresponding to the electric power stored in the battery module 31 of the battery device 11A, and supply it to each part of the vehicle 1A and the vehicle 1B. The DC / DC converters 12A, 12B are connected to the vehicle 1A, a driving motor for the vehicle 1B, the air conditioner in the vehicle 1A, the vehicle 1B, and the like. The DC / DC converters 12A and 12B supply a predetermined DC voltage to an inverter connected to the traveling motor in order to drive the traveling motor. Further, the DC / DC converters 12A and 12B supply a predetermined low DC voltage in order to drive a device that operates at a low voltage such as an air conditioner.

  The DC / DC converters 12A and 12B include a first DC / DC internal relay 41a and a second DC / DC internal relay 41b on the power lines connected to the battery devices 11A and 11B and the connection connector portions 13A and 13B. When the first DC / DC internal relay 41a and the second DC / DC internal relay 41b execute power transfer between the vehicle 1A and the vehicle 1B, the first DC / DC internal relay 41a and the second DC / DC internal relay 41b are in a conductive state (closed state) according to the control of the control units 14A and 14B. It is switched between the shut-off state (open state).

  When the own vehicle is connected to another vehicle, the control units 14A and 14B control each part of the vehicle 1A and the vehicle 1B described above in order to exchange electric power with the other vehicle (in-vehicle control). means). Control units 14A and 14B are connected to a connection detection sensor (not shown) and detect that power harness 2 is connected to connection connector portions 13A and 13B. When the power harness 2 is connected to the vehicle 1A and the vehicle 1B, the control units 14A and 14B determine that the battery module 31 is charged or discharged. For this purpose, the control units 14A and 14B perform the opening / closing operation of the first DC / DC internal relay 41a and the second DC / DC internal relay 41b, the first battery charging operation or the second battery charging operation, which will be described later, The switching operation of the main relay 32a and the second main relay 32b and the opening / closing operation of the precharge relay 33 are controlled. Thereby, control unit 14A, 14B makes the battery module 31 the state which can be charged or discharged.

  In such an inter-vehicle power discharging and charging system, the control units 14A and 14B function as in-vehicle control means for controlling the first main relay 32a and the second main relay 32b in the respective battery devices 11A and 11B. And the electric power harness 2 is connected to each connection connector part 13A, 13B, and the vehicle 1A and the vehicle 1B are connected between the vehicle electric power discharge / charge systems. At this time, the control units 14A and 14B determine that the battery module 31 is charged or discharged with power. And control unit 14A, 14B controls the opening / closing operation | movement of the 1st main relay 32a and the 2nd main relay 32b. At the same time, the variable resistance device 3 controls the operation of the resistance means so as to change the resistance value with respect to the current flowing through the power harness 2 (external control means).

  As described above, according to the inter-vehicle power discharging / charging system, when discharging the power between the vehicle 1A and the vehicle 1B, the energizing current flowing through the power harness 2 is suppressed by the resistance means, whereby the vehicle 1A, the vehicle It can suppress that a high inrush current flows between 1B.

[First battery charging operation]
Next, a description will be given of a first battery charging operation for transferring power between the vehicle 1A and the vehicle 1B in the inter-vehicle power discharging and charging system configured as described above.

  The inter-vehicle power discharging / charging system that performs the first battery charging operation includes a variable resistance device 3 configured as shown in FIG. The variable resistance device 3 includes an external resistance Ro and a first external relay 61 as resistance means, and a second external relay 62 in parallel with the external resistance Ro and the first external relay 61. The first external relay 61, the external resistor Ro, and the second external relay 62 are provided on one of a pair of power lines corresponding to the positive electrode and the negative electrode in the power harness 2. Nothing is provided on the other power line 63.

  The variable resistance device 3 has a control unit 64 as external control means. The control unit 64 closes the second external relay 62 (conducts) after closing the first external relay 61 (conducting state) when charging or discharging the battery module 31 of the vehicle 1A or vehicle 1B. State).

  In such an inter-vehicle power discharging system, the first battery charging operation is as shown in FIG. Thereby, in vehicle 1A and vehicle 1B, as shown in FIG. 4, the energization current in power harness 2 is suppressed. In the following description, the battery module 31 of the vehicle 1A has a sufficiently high charge amount, and the battery module 31 of the vehicle 1B has a low charge amount. The operation when 1B is connected will be described.

  In order to charge the vehicle 1A with the electric power of the vehicle 1A, an operator connects the connector portions 21A and 21B of the power harness 2 provided with the variable resistance device 3 to the connection connector portions 13A and 13B of the vehicle 1A and the vehicle 1B. Is connected. Then, the control units 14A and 14B of the vehicle 1A, the vehicle 1B, and the control unit 64 of the variable resistance device 3 detect in step S1 that the power harness 2 is connected to the connection connector portions 13A and 13B, and step S2 Proceed with the process.

  In step S2, the control units 14A and 14B turn on the first DC / DC internal relay 41a, the second DC / DC internal relay 41b, the first main relay 32a, and the precharge relay 33 in both the vehicle 1A and the vehicle 1B (conduction state). ). In this state, since the variable resistance device 3 is not in the conductive state, no current flows from the vehicle 1A to the vehicle 1B as shown at time t1 in FIG.

  In the next step S3, the control unit 64 turns on the first external relay 61. Thereby, the energization current according to the difference between the battery voltage of the battery module 31 of the vehicle 1A and the battery voltage of the battery module 31 of the vehicle 1B flows through the power line between the battery devices 11A and 11B. At this time, as shown at time t2 in FIG. 4, the energization current includes the potential difference between the battery modules 31, the energization resistance of the power harness 2, the various relays, the precharge relay 33, and the like, the internal resistance of the battery module 31, and the external resistance. The inrush current is in accordance with the sum of the resistance Ro. Here, the inter-vehicle power discharging / charging system is configured such that the inrush current when the first external relay 61 is turned on does not exceed a predetermined threshold (maximum allowable current), the storage capacity of the battery devices 11A and 11B, the external It is assumed that the resistor Ro is designed.

  By such step S3, electric power is sent from the battery module 31 of the vehicle 1A to the battery module 31 of the vehicle 1B.

  As described above, in both the vehicle 1A and the vehicle 1B, if the state in which the first main relay 32a, the precharging relay 33, and the first external relay 61 of the variable resistance device 3 are in the conductive state is continued, the potential difference between the battery modules 31 is maintained. Therefore, the energization current gradually decreases from time t2 onward in FIG. Then, after the control unit 64 brings the first external relay 61 into the conductive state, at time t3, which is a predetermined timing when the current flowing through the power harness 2 and the power line decreases, the second main relay 32b is reached at step S4. Is made conductive. The timing at which the second main relay 32b is turned on is such that the energization current does not exceed the threshold even if the second external relay 62 is turned on after the first external relay 61 is turned on at time t2. It is set when the energizing current becomes sufficiently low.

  Then, as shown at time t <b> 3 in FIG. 4, the energization current rushes in accordance with the potential difference between the battery modules 31 and the sum of the energization resistance of the power harness 2 and various relays and the internal resistance of the battery module 31. It becomes current.

  In the next step S5, the control unit 64 turns off the first external relay 61 (cut-off state) at time t4 in FIG. Thereby, in the variable resistance device 3, electric power is supplied from the vehicle 1A to the vehicle 1B only through the second external relay 62.

  In the inter-vehicle power discharging / charging system, it is desirable that the control units 14A and 14B turn off the precharging relay 33 (cut off state). Thereby, the vehicle 1A and the vehicle 1B can move electric power from the vehicle 1A to the vehicle 1B via the first main relay 32a and the second main relay 32b.

  Thus, the vehicle 1A and the vehicle 1B stop charging the electric power from the vehicle 1A to the vehicle 1B when the charge amounts of both the battery modules 31 become substantially the same and the change in the energization current decreases. . At this time, the control unit 64 puts the second external relay 62 in a cut-off state, and the control units 14A and 14B put the first DC / DC internal relay 41a and the second DC / DC internal relay 41b in a cut-off state. In the inter-vehicle power discharging / charging system, in the determination process for stopping the charging of the vehicle 1A, the vehicle 1B, and the variable resistance device 3, the current flowing through the power line by a current sensor (not shown) or the like is equal to or less than a predetermined threshold value. Can be determined.

  As described above, according to the inter-vehicle power discharging / charging system that performs the first battery charging operation, when charging power from the battery module 31 of the vehicle with a large amount of charge to the battery module 31 of the vehicle with a small amount of charge, First, a current is passed through the external resistance Ro of the variable resistance device 3. Thereby, according to this inter-vehicle power discharging / charging system, it is possible to avoid flowing an energizing current exceeding a threshold value that causes a problem in the circuits such as the battery devices 11A and 11B and the DC / DC converters 12A and 12B.

[Second battery charging operation]
Next, a description will be given of a third battery charging operation for transferring power between the vehicle 1A and the vehicle 1B in the inter-vehicle power discharging and charging system configured as described above.

  The inter-vehicle power discharging / charging system that performs the second battery charging operation includes a variable resistance device 3 configured as shown in FIG. The variable resistance device 3 is connected to the first contact 71a connected to the power harness 2 as a resistance means, the second contact 71b connected to the first contact and the external resistor Ro, and the first contact 71a. The changeover switch (SW) including the third contact 71c is assumed.

  When charging or discharging the battery module 31 of the vehicle 1A or the vehicle 1B, the control unit 64 connects the first contact 71a and the second contact 71b, and then connects the first contact 71a and the third contact 71c. Connect.

  In such an inter-vehicle power discharging system, the second battery charging operation is as shown in FIG. Thereby, in vehicle 1A and vehicle 1B, as shown in FIG. 7, the energization current in the power line is suppressed. In the following description, the battery module 31 of the vehicle 1A has a sufficiently high charge amount, and the battery module 31 of the vehicle 1B has a low charge amount. The operation when 1B is connected will be described.

  In order to charge the vehicle 1A with the electric power of the vehicle 1A, an operator connects the connector portions 21A and 21B of the power harness 2 provided with the variable resistance device 3 to the connection connector portions 13A and 13B of the vehicle 1A and the vehicle 1B. Is connected. Then, the control units 14A and 14B of the vehicle 1A, the vehicle 1B, and the control unit 64 of the variable resistance device 3 detect in step S1 that the power harness 2 is connected to the connection connector portions 13A and 13B, and step S2 Proceed with the process.

  In step S2, the control units 14A and 14B turn on the first DC / DC internal relay 41a, the second DC / DC internal relay 41b, the first main relay 32a, and the precharge relay 33 in both the vehicle 1A and the vehicle 1B (conduction state). ). In this state, since the variable resistance device 3 is not in the conductive state, no current flows from the vehicle 1A to the vehicle 1B as shown at time t1 in FIG.

  In the next step S3, the control unit 64 connects the first contact 71a of the switch SW to the second contact 71b side. Thereby, the energization current according to the difference between the battery voltage of the battery module 31 of the vehicle 1A and the battery voltage of the battery module 31 of the vehicle 1B flows through the power line between the battery devices 11A and 11B. At this time, as shown at time t11 in FIG. 7, the energization current includes the potential difference between the battery modules 31, the energization resistance of the power harness 2, various relays, the precharge relay 33, and the like, the internal resistance of the battery module 31, and the external resistance. The inrush current is in accordance with the sum of the resistance Ro. Here, the inter-vehicle power discharging / charging system is configured such that the inrush current when the first external relay 61 is turned on does not exceed a predetermined threshold (maximum allowable current), the storage capacity of the battery devices 11A and 11B, the external It is assumed that the resistor Ro is designed.

  By such step S3, electric power is sent from the battery module 31 of the vehicle 1A to the battery module 31 of the vehicle 1B.

  As described above, in both the vehicle 1A and the vehicle 1B, when the state in which the external resistor Ro is in the conductive state via the first main relay 32a, the precharge relay 33, and the second contact 71b of the variable resistor device 3 is continued, The potential difference between the modules 31 is reduced. At time t12 thereafter, the control unit 64 once disconnects the first contact 71a from the second contact 71b, and connects the first contact 71a to the third contact 71c (step S12).

  The timing at which the first contact 71a is switched to the third contact 71c is equal to the threshold value even if the first contact 71a is switched to the third contact 71c after the first contact 71a is switched to the second contact 71b at time t11. It is set when the energizing current is sufficiently low so as not to exceed.

  Then, as shown at time t <b> 12 in FIG. 7, the energization current rushes in accordance with the potential difference between the battery modules 31 and the sum of the energization resistance of the power harness 2 and various relays and the internal resistance of the battery module 31. It becomes current.

  Thereafter, in the inter-vehicle power discharging / charging system, it is desirable that the control units 14A and 14B turn off the precharging relay 33 (cut-off state) in the inter-vehicle power discharging / charging system. Thereby, the vehicle 1A and the vehicle 1B can move electric power from the vehicle 1A to the vehicle 1B via the first main relay 32a and the second main relay 32b.

  Thereafter, the vehicle 1A and the vehicle 1B stop charging the electric power from the vehicle 1A to the vehicle 1B when the charge amounts of both the battery modules 31 become substantially the same and the change in the energization current decreases. At this time, the control unit 64 opens the first contact 71a (cut-off state), and the control units 14A and 14B put the first DC / DC internal relay 41a and the second DC / DC internal relay 41b into a cut-off state. In the inter-vehicle power discharging / charging system, in the determination process for stopping the charging of the vehicle 1A, the vehicle 1B, and the variable resistance device 3, the current flowing through the power line by a current sensor (not shown) or the like is equal to or less than a predetermined threshold value. Can be determined.

  As described above, according to the inter-vehicle power discharging / charging system that performs the second battery charging operation, when charging power from the battery module 31 of the vehicle with a large amount of charge to the battery module 31 of the vehicle with a small amount of charge, First, a current is passed through the external resistance Ro of the variable resistance device 3. Thereby, according to this inter-vehicle power discharging / charging system, it is possible to avoid flowing an energizing current exceeding a threshold value that causes a problem in the circuits such as the battery devices 11A and 11B and the DC / DC converters 12A and 12B.

[Third battery charging operation]
Next, a description will be given of a third battery charging operation for transferring power between the vehicle 1A and the vehicle 1B in the inter-vehicle power discharging and charging system configured as described above.

  The inter-vehicle power discharging / charging system that performs the third battery charging operation includes a variable resistance device 3 configured as shown in FIG. The variable resistance device 3 has a variable resistance Rv as resistance means. When the battery module 31 of the vehicle 1A or the vehicle 1B is charged or discharged, the variable resistance device 3 changes the resistance value of the variable resistance Rv by the control unit 64 and suppresses the current flowing through the power harness 2. .

  In such an inter-vehicle power discharging system, the third battery charging operation is as shown in FIG. Thereby, in vehicle 1A and vehicle 1B, as shown in FIG. 10, the energization current in the power line is suppressed. In the following description, the battery module 31 of the vehicle 1A has a sufficiently high charge amount, and the battery module 31 of the vehicle 1B has a low charge amount. The operation when 1B is connected will be described.

  In order to charge the vehicle 1A with the electric power of the vehicle 1A, an operator connects the connector portions 21A and 21B of the power harness 2 provided with the variable resistance device 3 to the connection connector portions 13A and 13B of the vehicle 1A and the vehicle 1B. Is connected. Then, the control units 14A and 14B of the vehicle 1A, the vehicle 1B, and the control unit 64 of the variable resistance device 3 detect in step S1 that the power harness 2 is connected to the connection connector portions 13A and 13B, and step S2 Proceed with the process.

  In step S2, the control units 14A and 14B turn on the first DC / DC internal relay 41a, the second DC / DC internal relay 41b, the first main relay 32a, and the precharge relay 33 in both the vehicle 1A and the vehicle 1B (conduction state). ). In this state, the control unit 64 keeps the resistance value of the variable resistor Rv infinite. Thereby, in this state, since the variable resistance device 3 is not in a conductive state, as shown at time t1 in FIG. 10, no current flows from the vehicle 1A to the vehicle 1B.

  In the next step S <b> 21, the control unit 64 controls the resistance value of the variable resistor Rv to the maximum value in the range in which current flows through the power harness 2. Accordingly, at time t21 in FIG. 10, an energization current corresponding to the difference between the battery voltage of the battery module 31 of the vehicle 1A and the battery voltage of the battery module 31 of the vehicle 1B flows through the power line between the battery devices 11A and 11B. . At this time, as shown at time t21 in FIG. 10, the energization current is variable between the potential difference between the battery modules 31, the energization resistance of the power harness 2, the various relays, the precharge relay 33, and the like, and the internal resistance of the battery module 31. The inrush current is in accordance with the sum of the resistance Rv and the maximum resistance value. Here, in the inter-vehicle power discharging / charging system, the storage capacities of the battery devices 11A and 11B are variable so that the inrush current when the first external relay 61 is turned on does not exceed a predetermined threshold (maximum allowable current). It is assumed that the resistor Rv is designed.

  In the next step S22, the control unit 64 gradually decreases the resistance value of the variable resistor Rv so that the value of the current flowing through the power harness 2 is constant. Then, in step S23, the control unit 64 determines whether or not the variable resistance Rv has reached the minimum value (0Ω). If the variable resistance Rv is not at the minimum value, the process returns to step S22, and the resistance value of the variable resistance Rv is further reduced. On the other hand, if it is determined that the variable resistance Rv has reached the minimum value, the third battery charging operation is terminated.

  In this way, by reducing the resistance value of the variable resistor Rv so that the current value flowing through the power harness 2 is constant, as shown in FIG. 10, the energization current is applied over a period T from time t21 to time t22. The power is sent from the battery module 31 of the vehicle 1A to the battery module 31 of the vehicle 1B.

  Thus, in both the vehicle 1A and the vehicle 1B, when the state in which the variable resistor Rv is in the conductive state via the first main relay 32a, the precharge relay 33, and the second contact 71b of the variable resistor device 3 continues, The potential difference between the modules 31 is reduced. Thereafter, at time t21, the control unit 64 sets the resistance value of the variable resistor Rv to the lowest value at time t21. Then, the energization current is a value from a value corresponding to the potential difference between the battery modules 31 and the sum of the energization resistance of the power harness 2 and various relays and the internal resistance of the battery module 31 from time t22 in FIG. It becomes.

  Thereafter, in the inter-vehicle power discharging / charging system, it is desirable that the control units 14A and 14B turn off the precharging relay 33 (cut-off state) in the inter-vehicle power discharging / charging system. Thereby, the vehicle 1A and the vehicle 1B can move electric power from the vehicle 1A to the vehicle 1B via the first main relay 32a and the second main relay 32b.

  Thus, the vehicle 1A and the vehicle 1B stop charging the electric power from the vehicle 1A to the vehicle 1B when the charge amounts of both the battery modules 31 become substantially the same and the change in the energization current decreases. . At this time, the control unit 64 opens the first contact 71a (cut-off state), and the control units 14A and 14B put the first DC / DC internal relay 41a and the second DC / DC internal relay 41b into a cut-off state. In the inter-vehicle power discharging / charging system, in the determination process for stopping the charging of the vehicle 1A, the vehicle 1B, and the variable resistance device 3, the current flowing through the power line by a current sensor (not shown) or the like is equal to or less than a predetermined threshold. Can be determined.

  As described above, according to the inter-vehicle power discharging / charging system that performs the third battery charging operation, when charging power from the battery module 31 of the vehicle with a large amount of charge to the battery module 31 of the vehicle with a small amount of charge, The variable resistor Rv is gradually lowered so that the energization current is constant. Thereby, according to this inter-vehicle power discharging / charging system, it is possible to avoid flowing an energizing current exceeding a threshold value that causes a problem in the circuits such as the battery devices 11A and 11B and the DC / DC converters 12A and 12B.

[Fourth battery charging operation]
Next, a description will be given of a fourth battery charging operation for transferring power between the vehicle 1A and the vehicle 1B in the inter-vehicle power discharging and charging system configured as described above.

  The inter-vehicle power discharging / charging system that performs the fourth battery charging operation includes a variable resistance device 3 configured as shown in FIG. 11. The variable resistance device 3 includes a plurality of external resistors and external relays connected in series as resistance means, connected in parallel to each other. In this example, external relay 81a and external resistor R1, external relay 81b and external resistor R2, external relay 81c and external resistor R3, external relay 81c and external resistor R4, external relay 81d and external resistor R5, external relay 81e and external resistor R6, 5 sets of external relays and external resistors are connected in parallel.

  When the battery module 31 of the vehicle 1A or the vehicle 1B is charged or discharged with power, the variable resistance device 3 causes the control unit 64 to sequentially close the external relays (conduction state) so that the power harness 2 The energizing current flowing through the is suppressed. The external resistors R1 to R5 may have the same resistance value, and may be external resistance R1> external resistance R2> external resistance R3> external resistance R4> external resistance R5. Furthermore, the number of combinations of external relays and external resistors is not limited to this.

  In such an inter-vehicle power discharging system, the first battery charging operation is as shown in FIG. Thereby, in vehicle 1A and vehicle 1B, as shown in FIG. 13, the energization current in the power line is suppressed. In the following description, the battery module 31 of the vehicle 1A has a sufficiently high charge amount, and the battery module 31 of the vehicle 1B has a low charge amount. The operation when 1B is connected will be described.

  In order to charge the vehicle 1A with the electric power of the vehicle 1A, an operator connects the connector portions 21A and 21B of the power harness 2 provided with the variable resistance device 3 to the connection connector portions 13A and 13B of the vehicle 1A and the vehicle 1B. Is connected. Then, the control units 14A and 14B of the vehicle 1A, the vehicle 1B, and the control unit 64 of the variable resistance device 3 detect in step S1 that the power harness 2 is connected to the connection connector portions 13A and 13B, and step S2 Proceed with the process.

  In step S2, the control units 14A and 14B turn on the first DC / DC internal relay 41a, the second DC / DC internal relay 41b, the first main relay 32a, and the precharge relay 33 in both the vehicle 1A and the vehicle 1B (conduction state). ). In this state, since the variable resistance device 3 is not in a conductive state, no current flows from the vehicle 1A to the vehicle 1B as shown at time t1 in FIG.

  In the next step S31, the control unit 64 turns on the external relay 81a. Thereby, the energization current according to the difference between the battery voltage of the battery module 31 of the vehicle 1A and the battery voltage of the battery module 31 of the vehicle 1B flows through the power line between the battery devices 11A and 11B. At this time, as shown at time t31 in FIG. 13, the energization current includes the potential difference between the battery modules 31, the energization resistance of the power harness 2, the various relays, the precharge relay 33, and the like, the internal resistance of the battery module 31, and the external resistance. Inrush current according to the sum of the resistance R1. Here, the inter-vehicle power discharging / charging system is configured such that the inrush current when the first external relay 61 is turned on does not exceed a predetermined threshold (maximum allowable current), the storage capacity of the battery devices 11A and 11B, the external It is assumed that the resistor R1 is designed. In the case where the resistance values are different among the plurality of external resistors R1 to R5, the external resistor R having the highest resistance value is first conducted to suppress inrush current. By such step S31, electric power is sent from the battery module 31 of the vehicle 1A to the battery module 31 of the vehicle 1B.

  Next, the variable resistance device 3 sequentially turns on the external relay 81b, the external relay 81c,... In step S32, step S33. As a result, the total resistance value of the external resistors in the variable resistance device 3 gradually decreases from R1 to 1 / (1 / R1 + 1 / R2), 1 / (1 / R1 + 1 / R2 + 1 / R3),. As a result, at times t32 and t33, the energization current is set to a threshold value or less.

  In this way, the external relays are sequentially turned on, and in step S34 (time t34), all the external relays 81a to 81e in the variable resistance device 3 are turned on, and the total resistance value of the external resistances R of the variable resistance device 3 is minimized. Value. In this state, the electric power of the vehicle 1A is supplied to the vehicle 1B, and the vehicle 1A and the vehicle 1B have the same amount of charge in both battery modules 31, and the change in the energization current is reduced. Charging of power from 1A to vehicle 1B is stopped. At this time, the control unit 64 puts the second external relay 62 in a cut-off state, and the control units 14A and 14B put the first DC / DC internal relay 41a and the second DC / DC internal relay 41b in a cut-off state. In the inter-vehicle power discharging / charging system, in the determination process for stopping the charging of the vehicle 1A, the vehicle 1B, and the variable resistance device 3, the current flowing through the power line by a current sensor (not shown) or the like is equal to or less than a predetermined threshold value. Can be determined.

  In the inter-vehicle power discharging / charging system, when the resistance value of the variable resistance device 3 reaches or reaches the maximum resistance value, the control units 14A and 14B turn off the precharge relay 33 (cut off state). Is desirable. Thereby, the vehicle 1A and the vehicle 1B can move electric power from the vehicle 1A to the vehicle 1B via the first main relay 32a and the second main relay 32b.

  In the inter-vehicle power discharging / charging system that performs the fourth battery charging operation described above, the external resistors R1 to R5 are designed to have a current-carrying resistance and a change rate in the entire variable resistance device 3 as shown in FIGS. 14 and 15, for example. can do. The change degree of the total energization resistance value of the variable resistance device 3 and the change rate of the total energization resistance value of the variable resistance device 3 shown in FIG. 14 and FIG. 15 are determined by turning on the external relays 81a to 81e sequentially. It is a case where it supplies with electricity sequentially to -R5.

  The total energization resistance of the variable resistance device 3 when the external resistances R1 to R5 are all constant (when the resistance is constant) is 1,0.5, 0.33 when the external relays 81a to 81e are sequentially turned on. It becomes lower sequentially such as 0.25 and 0.20. Further, the rate of change of the total energization resistance of the variable resistance device 3 is 0.5 when the external resistance R2 is energized next to the external resistance R1, and is sequentially 0.34, 0.24, 0.20. Become.

  The variable resistance device 3 when the resistances of the external resistors R1 to R5 are changed so that R1 (1)> R2 (0.95)> R3 (0.5)> R4 (0.25)> R5 (0.12). The overall energization resistance and rate of change are also shown in FIGS. In this case, when the external relays 81a to 81e are sequentially turned on, the total energization resistance of the variable resistance device 3 is sequentially decreased, such as 1,0.49, 0.25, 0.12, 0.06. Further, the rate of change of the total energization resistance of the variable resistance device 3 is 0.49 when the external resistance R2 is energized next to the external resistance R1, and sequentially 0.51, 0.50, 0.49. Become. Thus, the inrush current can be made constant by making the rate of change of all the energization resistances of the variable resistance device 3 substantially the same and shortening the interval of sequentially energizing each external resistance.

  As described above, according to the inter-vehicle power discharging and charging system that performs the fourth battery charging operation, the external resistance and the external relay connected in series are provided in parallel with each other, and the external relay is sequentially turned on. Go. Thus, according to the inter-vehicle power discharging / charging system, the electric current can be discharged / charged between the vehicle 1A and the vehicle 1B while gradually reducing the external resistance value while suppressing the energization current flowing through the power harness 2. it can.

  The above-described embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and various modifications can be made depending on the design and the like as long as the technical idea according to the present invention is not deviated from this embodiment. Of course, it is possible to change.

1A, 1B Vehicle 2 Power harness 3 Variable resistance device 11A, 11B Battery device 12A, 12B DC / DC converter 13A, 13B Connection connector portion 14A, 14B Control unit 21A, 21B Connector portion 22 Power line 31 Battery module 32a First main relay 32b Second main relay 33 Precharge relay 34 Precharge resistor 41a First DC / DC internal relay 41b Second DC / DC internal relay 51a, 51b Coupling portion 61 First external relay 62 Second external relay 63 Power line 64 Control unit 71a First Contact 71b Second contact 71c Third contact 81a to 81e External relay

Claims (6)

An inter-vehicle power discharging / charging system for transferring power between vehicles,
A variable resistance device that is provided in a power harness connecting between vehicles and includes a resistance unit that suppresses a current flowing in the power harness, and an external control unit that controls the operation of the resistance unit;
And a power discharge / charge device mounted on each vehicle,
The power discharging / charging device is:
A connection means connected via a power harness to a power discharging / charging device mounted on another vehicle;
Power storage means for storing electric power supplied to each part of the host vehicle;
A relay connected to the power storage means;
Vehicle-mounted control means for controlling the opening and closing operation of the relay,
When charging or discharging power to the power storage means,
The vehicle-mounted control means controls the opening / closing operation of the relay,
The external control means controls the operation of the resistance means so as to change a resistance value with respect to a current flowing through the power harness. The resistance means includes an external resistor and a first external relay, and a second external relay in parallel with the external resistor and the first external relay,
When charging or discharging power to the power storage means,
The inter-vehicle power discharging / charging system according to claim 1, wherein the external control unit closes the second external relay after closing the first external relay. The resistance means includes a first contact connected to the power harness, a second contact connected to the first contact and an external resistor, and a third contact connected to the first contact.
When charging or discharging power to the power storage means,
The inter-vehicle power release according to claim 1, wherein the external control unit connects the first contact and the third contact after connecting the first contact and the second contact. Charging system. The resistance means comprises a variable resistance,
When charging or discharging power to the power storage means,
The inter-vehicle power discharging / charging system according to claim 1, wherein the external control unit changes a resistance value of the variable resistor so that a current flowing through the power harness is constant. The resistance means includes a plurality of external resistors and external relays connected in series, connected in parallel to each other,
When charging or discharging power to the power storage means,
The inter-vehicle power discharging / charging system according to claim 1, wherein the external control unit sequentially closes the external relays to suppress a current flowing through the power harness. A vehicle-to-vehicle power discharging / charging method for transferring power between vehicles,
When charging or discharging electric power with respect to power storage means for connecting electric power harnesses between vehicles and storing electric power supplied to each part of the host vehicle,
By controlling the opening and closing operation of the relay connected to the power storage means by each vehicle, the electric power can be charged or discharged by the power storage means of each vehicle,
A variable resistance device provided in a power harness connecting between vehicles and having a resistance means for suppressing current flowing in the power harness is turned on, and a current flowing in the power harness is allowed to flow to the resistance means. A vehicle-to-vehicle power discharging method.

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