JP5548484B2 - Vehicle power supply system - Google Patents

Description

  The present invention includes a power control unit configured by unitizing a voltage converter that boosts an output voltage of a battery and a power converter that supplies a voltage converted by the voltage converter to a motor, including peripheral circuits thereof, The present invention relates to a vehicle power supply system including a cooling device that circulates a refrigerant to cool the power control unit.

  A vehicle power supply system that cools a power control unit by circulating a refrigerant is known from Patent Document 1.

JP 2009-27901 A

  By the way, the voltage converter of the power unit boosts the output voltage of the battery, and the power from the power converter of the power control unit is supplied to the motor. The battery and the motor also need to be cooled. In the device disclosed in No. 1, a cooling device for cooling the battery and the motor is required in addition to the cooling device for cooling the power control unit, and a compact cooling device is desired.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle power supply system that enables a cooling device to be made compact.

In order to achieve the above object, the present invention comprises a voltage converter that boosts the output voltage of a battery and a power converter that supplies a voltage converted by the voltage converter to a motor, including its peripheral circuits. In a vehicle power supply system comprising a configured power control unit, and a cooling device that circulates a refrigerant to cool the power control unit, a pump that circulates the refrigerant, and a radiator that cools the refrigerant by cooling. The cooling device includes a discharge side of the pump that sucks the refrigerant from the radiator and the power control unit, wherein the refrigerant sequentially passes through the power control unit, the battery, and the motor in this order from the radiator. heater and wherein Rukoto interposed between.

The present invention also provides a power control unit configured by unitizing a voltage converter for boosting an output voltage of a battery and a power converter for supplying a voltage converted by the voltage converter to a motor including its peripheral circuits. A cooling device that circulates a refrigerant and cools the power control unit, and includes a pump that circulates the refrigerant and a radiator that cools the refrigerant by cooling. A refrigerant is configured to sequentially pass through the power control unit, the battery, and the motor from the radiator in this order, and individual bypass circuits are connected to the power control unit, the battery, the motor, and the radiator, respectively. Is the second feature.

According to the present invention, in addition to the configuration of the second feature, the cooling device is configured to supply the refrigerant to each bypass circuit according to the temperature of the refrigerant flowing through the power control unit, the battery, the motor, and the radiator. A third feature is that a control valve means for controlling distribution is provided in the power control unit, the battery, the motor, and the radiator.

Furthermore, the present invention provides a control device for controlling the operation of the pump, in addition to the configuration of the third feature, wherein the power control unit, the battery, and the motor are individually set with minimum temperatures to be maintained. However, according to a fourth aspect of the present invention, the pump operation is stopped when the refrigerant temperature is lower than the minimum temperature in any of the power control unit, the battery, and the motor.

According to the first and second features of the present invention, the cooling device is configured such that the refrigerant sequentially passes through the radiator, the power control unit, the battery, and the motor in this order, so that in addition to the power control unit, the motor and The battery can be cooled and the power control unit, battery, motor and radiator are combined into a united cooling device to make the cooling device more compact, and the wiring and piping that make up part of the cooling device Can be shortened.

In particular , according to the first feature of the present invention, the temperature of the battery at a low temperature can be raised by heating the refrigerant with a heater interposed between the discharge side of the pump and the power control unit.

In particular , according to the second feature of the present invention, the refrigerant can be circulated through the bypass circuit individually connected to the power control unit, the battery, the motor, and the radiator, so that the power control unit, the battery, the motor, and the radiator are circulated. The refrigerant can be circulated only when necessary.

According to the third aspect of the present invention, the amount of refrigerant flowing through the bypass circuit individually corresponding to the power control unit, the battery, the motor, and the radiator depends on the temperature of the refrigerant flowing through the power control unit, the battery, the motor, and the radiator. By controlling with the control valve means, it is possible to perform optimum cooling according to the states of the power control unit, the battery, the motor, and the radiator.

Furthermore, according to the fourth aspect of the present invention, the cooling of the power control unit, the battery and the motor is stopped by stopping the operation of the pump when the temperature of the refrigerant has not reached the minimum temperature set individually for them. It is possible to avoid unnecessary energy loss by operating the pump when it is not needed.

It is a side view which shows arrangement | positioning of the vehicle power supply system seeing through a vehicle. It is a perspective view which shows arrangement | positioning of the power supply system for vehicles seeing through a vehicle. It is a circuit diagram which shows the structure of a power control unit. It is a figure which shows the structure of a cooling device. It is a figure which shows an example of the temperature change of the cooling water in a cooling device. It is a block diagram which shows schematic structure of a fuel cell system.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. First, in FIGS. 1 and 2, a battery 16 is provided in a motor room 4 at the front of a vehicle V that is a fuel cell vehicle. The power control unit 7 disposed above the battery 16 is disposed as a unit, and the battery 16 and the power control unit 7 are accommodated in a common case 8. Further, a radiator 9 is disposed in front of the battery 16 and the power control unit 7, and a motor 17 that exerts power for driving driving wheels such as left and right front wheels WF is disposed below the battery 16.

  A fuel cell unit 10 including a fuel cell 15 as a power generation source is disposed adjacent to the sides of the battery 16 and the power control unit 7. In this embodiment, the support extends in the front-rear direction. The fuel cell unit 10 supported on the gantry 11 is disposed close to the battery 16 and the power control unit 7 from behind.

  Moreover, the battery 16, the power control unit 7, the radiator 9 and the motor 17 are disposed in the motor room 4 isolated from the vehicle compartment 5 of the vehicle V, and the support frame 11 and the fuel cell unit 10 are The partition wall 12 is interposed between the passenger compartment 5 and the passenger compartment 5 so as to be isolated from the passenger compartment 5 and disposed below the passenger compartment 5, for example, between the driver seat and the passenger seat in the passenger compartment 5. .

  An air supply device 13 connected to the fuel cell unit 10 is disposed in the motor room 4 so as to be interposed between the battery 16 and the power control unit 7 and the radiator 9, and A high-pressure hydrogen tank 14 connected to the battery unit 10 is disposed in the trunk room 6 behind the vehicle compartment 5.

In FIG. 3, the power control unit 7 includes a first voltage converter 18 that boosts the voltage of the fuel cell 15, a second voltage converter 19 that boosts the voltage of the battery 16, a first and a first voltage converter 18. A power converter 20 that supplies the voltage converted by the two voltage converters 18 and 19 to the motor 17, and a DC link capacitor unit 21 that is a peripheral circuit of the voltage converters 1 8 and 19 and the power converter 20, and Is provided.

  The first voltage converter 18 includes a first input capacitor 22, a first inductor 24, a three-phase transformer 26 having a primary winding 26A, a secondary winding 26B, and a tertiary winding 26C, and first and second And third switching element modules 27A, 27B, and 27C.

  A ground line 28 that is common to the first voltage converter 18, the second voltage converter 19, and the power converter 20 is connected to the negative terminal of the fuel cell 15, and the first input capacitor 22 is Provided between the first input positive line 29 connected to the positive terminal of the fuel cell 15 and the ground line 28, one end of the first inductor 24 is connected to the first input positive line 29. One end of the primary winding 26A, the secondary winding 26B, and the tertiary winding 26C in the three-phase transformer 26 is connected in parallel to the other end of the first inductor 24.

  The first switching element module 27 </ b> A is disposed between the common plus line 30 common to the first voltage converter 18, the second voltage converter 19, and the power converter 20 and the primary winding 26 </ b> A of the three-phase transformer 26. The first plus-side switching element 31A and the first minus-side switching element 32A disposed between the primary winding 26A and the ground line 28, and the second switching element module 27B includes the common plus line 30 and a second plus-side switching element 31B disposed between the secondary winding 26B of the three-phase transformer 26, and a second minus-side switching element disposed between the secondary winding 26B and the ground line 28. 32B, and the third switching element module 27C includes the common plus line 30 and the three-phase And a third positive side switching element 31C is disposed between the tertiary winding 26C of Nsu 26, and a third negative side switching element 32C is disposed between the tertiary winding 26C and the ground line 28.

  The second voltage converter 19 includes a second input capacitor 23, a second inductor 25, a two-phase transformer 33 having a primary winding 33A and a secondary winding 33B, fourth and fifth switching element modules 27D, 27E.

  The second input capacitor 23 is provided between a second input side plus line 34 connected to the plus side terminal of the battery 16 and a ground line 28 connected to the minus side terminal of the battery 16, and the second inductor 25. Is connected to the second input side plus line 34. One end of the primary winding 33 </ b> A and the secondary winding 33 </ b> B in the two-phase transformer 33 is connected in parallel to the other end of the second inductor 25.

  The fourth switching element module 27D includes a fourth positive switching element 31D disposed between the common plus line 30 and the primary winding 33A of the two-phase transformer 33, and between the primary winding 33A and the ground line 28. And a fifth switching element module 27E is provided between the common plus line 30 and the secondary winding 33B of the two-phase transformer 33. An element 31E and a fifth negative switching element 32E disposed between the secondary winding 33B and the ground line 28 are provided.

  The power converter 20 includes sixth, seventh, and eighth switching element modules 27F, 27G, and 27H.

  The sixth switching element module 27F includes a sixth plus-side switching element 31F disposed between the common plus line 30 and the U-phase power supply line 35U connected to the electric motor 17 which is a three-phase AC motor, And a sixth negative switching element 32F disposed between the power line 35U and the ground line 28. The seventh switching element module 27G includes a V-phase power line 35V connected to the common positive line 30 and the electric motor 17. A seventh plus-side switching element 31G disposed between the V-phase power supply line 35V and the ground line 28, and an eighth switching element module 27H includes: The common plus line 30 and the electric motor 17. Comprising an eighth positive side switching element 31H disposed between becomes W phase power supply line 35W, and an eighth negative side switching element 32H disposed between the W phase power supply line 35W and the ground line 28.

  By the way, in this embodiment, the first to eighth plus side switching elements 31A to 31H and the first to eighth minus side switching elements 32A to 32H in the first to eighth switching element modules 27A to 27H are IGBTs (Insulatead Gate). Bipolar Transistor) and a diode connected in parallel to each IGBT with the side from the emitter toward the collector as the forward direction.

  The DC link capacitor unit 21 has smoothing capacitors 36... Provided between the common plus line 30 and the ground line 28. Although only one smoothing capacitor 36 is shown in FIG. 3 for the sake of simplification, the DC link capacitor unit 21 includes a U-phase, a V-phase, and a W-phase of the electric motor 17 that is a three-phase AC motor. Smoothing capacitors 36... Provided between the common plus line 30 and the ground line 28 corresponding to the phases are provided.

  A series circuit including a pair of discharge resistors 37 and 37 is connected between the common plus line 30 and the ground line 28.

  In FIG. 4, the power control unit 7 is cooled by a cooling device 40 that circulates a coolant, for example, cooling water. The cooling device 40 includes a pump 41 that circulates cooling water and a cooling water that is allowed to cool. The radiator 9 for cooling is included, and the cooling water sequentially passes from the radiator 9 to the power control unit 7, the battery 16, and the motor 17 in this order, and the suction side of the pump 41 is the radiator. 9, a heater 42 is interposed between the discharge side of the pump 41 and the power control unit 7.

  The power control unit 7, the battery 16, the motor 17, and the radiator 9 are connected to individual bypass circuits 43, 44, 45, and 46, respectively. Moreover, the circulation of the cooling water to the power control unit 7, the battery 16, the motor 17 and the radiator 9, and the circulation of the cooling water to the bypass circuits 43 to 46 are performed by the power control unit 7, the battery 16, The switching is controlled by the operation of the control valve means 47, 48, 49, 50 controlled by the control device 51 in accordance with the temperature of the refrigerant flowing through the motor 17 and the radiator 9.

  Thus, the control valve means 47 corresponding to the power control unit 7 comprises three-way electromagnetic switching valves V1 and V2 provided respectively at the inlet and outlet of the bypass circuit 43, and the control valve means 48 corresponding to the battery 16 is bypassed. The control valve means 49 corresponding to the motor 17 comprises three-way electromagnetic switching valves V5, V6 respectively provided at the inlet and the outlet of the bypass circuit 45. The control valve means 50 corresponding to the radiator 9 includes three-way electromagnetic switching valves V7 and V8 provided at the inlet and the outlet of the bypass circuit 46, respectively.

  The control valve means 47 to 50 may be thermostats that automatically operate without being controlled by the control device 51.

By the way, the power control unit 7, the battery 16, the motor 17, and the radiator 9 have temperature ranges to be maintained. In the power control unit 7, the temperature T is higher than the temperature TA (for example, 40 degrees C). And a temperature range (TA <T <TB) that is less than temperature TB (for example, 100 degrees C) is set. In battery 16, temperature T is greater than temperature TC (for example, 0 degrees C) and temperature TD (for example, A temperature range (TC <T <TD) that is less than 60 degrees C) is set, and in the motor 17, the temperature T is greater than the temperature TE (for example, 0 degrees C) and less than the temperature TF (for example, 100 degrees C). set temperature range (TE <T <TF) is, in the radiator 9, so that the temperature T of the cooling water to be introduced is a temperature TG (Tatoba 70 ° C) Is constant, the control valve means 47 to 50 is, the power control unit 7, the battery 16 becomes controlled by it so as to hold the set temperature range of the motor 17 and the radiator 9.

  By setting such a temperature range, the temperature of the cooling water in the cooling device 40 changes, for example, as shown in FIG. Thus, during cold start, the temperature of the cooling water changes as shown by the broken line in FIG. 5, during normal driving, the temperature of the cooling water changes as shown by the solid line in FIG. As shown by the chain line, the temperature of the cooling water changes.

The operation of the pump 41 is also controlled by the control device 51. The control device 51 includes the minimum temperatures to be set by the power control unit 7, the battery 16, and the motor 17, that is, T A and T C. , TE are individually set, and the control device 51 stops the operation of the pump 41 when the temperature of the cooling water is below the minimum temperature in any of the power control unit 7, the battery 16 and the motor 17.

  In FIG. 6, pressurized air from the air supply device 13 is supplied to the fuel cell 15 via a humidifier 53 and high-pressure hydrogen is supplied from the high-pressure hydrogen tank 14 via a regulator 54. Then, the hydrogen sucked by the circulation pump 55 is returned to the downstream side of the regulator 54 through the check valve 56. An open / close valve 57 is connected between the circulation pump 55 and the check valve 56.

In such a fuel cell system, the humidifier 53, the regulator 54, the circulation pump 55, and the check valve 56 are integrated as an auxiliary device 52 into a unit, and constitutes the fuel cell unit 10 together with the fuel cell 15. As shown in FIGS. 1 and 2, the fuel cell 15 is arranged behind the fuel cell 15 and supported by the support frame 11.

  Next, the operation of this embodiment will be described. The power control unit 7 including the first voltage converter 18, the second voltage converter 19, and the power converter 20 and the battery 16 are unitized into the vehicle. Since it is isolated from the chamber 5 and disposed at the front of the vehicle, it is possible to shorten the electrical wiring and cooling piping connecting the power control unit 7 and the battery 16, and the luggage storage space at the rear of the vehicle 5 and the vehicle. This makes it easy to protect the electrical wiring and the cooling pipe, avoids an increase in the number of parts required for protection, and reduces the space required for protection. Also, by shortening the electrical wiring, radiation noise generated during energization can be reduced and simplification of shielding measures can be achieved. Since there are no electrical wiring and cooling piping under the floor, the electrical wiring and cooling piping can be grounded or the road surface There is no worry that the electric wiring and cooling piping collide with the protrusions etc. on the top.

  In addition, since the fuel cell unit 10 including the fuel cell 15 is disposed at a position close to the side of the battery 16 and the power control unit 7 (rear in this embodiment) and separated from the vehicle compartment 5, the power control is performed. In addition to the unit 7 and the battery 16, the fuel cell unit 10 can be gathered and arranged close to each other, and the operation sound of the fuel cell unit 10 can be prevented from entering the vehicle compartment 5.

  The cooling device 40 that circulates the cooling water to cool the power control unit 7 includes a pump 41 that circulates the cooling water and a radiator 9 that cools the cooling water by cooling. 7, since the refrigerant is configured to sequentially pass through the battery 16 and the motor 17 in this order, the motor 17 and the battery 16 can be cooled in addition to the power control unit 7, and the power control unit 7, the battery 16, The cooling device 40 in which the motor 17 and the radiator 9 are integrated into a unit is configured, so that the cooling device 40 can be made compact, and wiring and piping constituting a part of the cooling device 40 can be shortened. it can.

Further, since the heater 42 is interposed between the discharge side of the pump 41 that sucks the cooling water from the radiator 9 and the power control unit 7, the temperature of the battery 16 at a low temperature is raised by heating the cooling water with the heater 42 . be able to.

  Since the individual bypass circuits 43, 44, 45, and 46 are connected to the power control unit 7, the battery 16, the motor 17, and the radiator 9, respectively, cooling water can be circulated through these bypass circuits 43 to 46. In this way, the refrigerant can be circulated through the power control unit 7, the battery 16, the motor 17 and the radiator 9 only when necessary.

  The cooling device 40 is a control valve means for controlling the flow of cooling water to the bypass circuits 43, 44, 45, 46 in accordance with the temperature of the refrigerant flowing through the power control unit 7, the battery 16, the motor 17 and the radiator 9. 47, 48, 49, 50 are provided for each power control unit 7, battery 16, motor 17 and radiator 9, so that the bypass circuits 43 to 46 individually corresponding to the power control unit 7, battery 16, motor 17 and radiator 9 are provided. The control valve means 47-50 controls the amount of refrigerant to flow according to the temperature of the cooling water flowing through the power control unit 7, battery 16, motor 17 and radiator 9, so that the power control unit 7, battery 16, motor 17 And optimum according to the state of the radiator 9 Cooling can be performed.

  Further, the power control unit 7, the battery 16, and the motor 17 are individually set with minimum temperatures to be held, and the control device 51 that controls the operation of the pump 41 includes the power control unit 7, the battery 16 and the motor 17. In any case, since the operation of the pump 41 is stopped when the temperature of the cooling water is equal to or lower than the minimum temperature, it is possible to avoid a wasteful energy loss by operating the pump 41 when cooling is unnecessary.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

  For example, in the above-described embodiment, the case where the fuel cell 15 is used as a power generation source has been described. However, the present invention can also be applied to a case where a generator driven by an engine is used as a power generation source in a hybrid vehicle.

DESCRIPTION OF SYMBOLS 7 ... Power control unit 9 ... Radiator 16 ... Battery 17 ... Motor 18, 19 ... Voltage converter 20 ... Power converter 40 ... Cooling device 41 ... Pump 42 ... Heaters 43, 44, 45, 46 ... Bypass circuits 47, 48, 49, 50 ... Control valve means 51 ... Control device

Claims (4)

The voltage converter (18, 19) for boosting the output voltage of the battery (16) and the power converter (20) for supplying the voltage converted by the voltage converter (18, 19) to the motor (17) In a vehicle power supply system comprising: a power control unit (7) configured as a unit including a circuit; and a cooling device (40) for circulating the refrigerant to cool the power control unit (7). The cooling device (40) including a circulating pump (41) and a radiator (9) that cools the refrigerant by cooling is provided from the radiator (9) to the power control unit (7) and the battery (16). and consists of the motor (17) as the refrigerant in this order sequentially passes, said aspirating the coolant from the radiator (9) Pump (41) the discharge side and the power control unit (7) heater between (42) is interposed vehicle power supply system for a characterized by Rukoto of. The voltage converter (18, 19) for boosting the output voltage of the battery (16) and the power converter (20) for supplying the voltage converted by the voltage converter (18, 19) to the motor (17) In a vehicle power supply system comprising: a power control unit (7) configured as a unit including a circuit; and a cooling device (40) for circulating the refrigerant to cool the power control unit (7). The cooling device (40) including a circulating pump (41) and a radiator (9) that cools the refrigerant by cooling is provided from the radiator (9) to the power control unit (7) and the battery (16). and a refrigerant said motor (17) in this order is configured to sequentially pass, the power control unit (7), the back Li (16), said motor (17) and said radiator (9), vehicle dual power system that is characterized in that each individual bypass circuit (43, 44, 45, 46) are connected.   The cooling device (40) includes the bypass circuits (43 to 46) according to the temperature of the refrigerant flowing through the power control unit (7), the battery (16), the motor (17), and the radiator (9). Control valve means (47, 48, 49, 50) for controlling the flow of the refrigerant to each of the power control unit (7), the battery (16), the motor (17) and the radiator (9). The power supply system for vehicles according to claim 2 provided. The power control unit (7), the battery (16) and the motor (17) are individually set with minimum temperatures to be maintained, and a control device (51) for controlling the operation of the pump (41). However, in any of the power control unit (7), the battery (16), and the motor (17), the operation of the pump (41) is stopped when the temperature of the refrigerant is equal to or lower than the minimum temperature. The vehicle power supply system according to claim 3 .

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