阅读说明：本技术 电力控制装置 (Power control device ) 是由 杉田昌行 坂田浩一 筱原正俊 于 2020-08-20 设计创作，主要内容包括：本说明书涉及包括2个逆变器的电力控制装置,提供即使在第2逆变器中产生短路故障时也能够使用第1逆变器的技术。在本说明书公开的电动汽车中,电力控制装置具备连接直流电源的输入端、第1逆变器、第2逆变器、开关。第1逆变器和第2逆变器与输入端连接。即,第1逆变器和第2逆变器被电连接。第1逆变器将直流电源的电力变换为行驶用的第1马达的驱动电力。第2逆变器将直流电源的电力变换为第2马达的驱动电力。开关能够将第2逆变器从输入端以及第1逆变器电气地断开。(The present specification relates to a power control apparatus including 2 inverters, and provides a technique capable of using a 1 st inverter even when a short-circuit fault occurs in the 2 nd inverter. In the electric vehicle disclosed in the present specification, the power control device includes an input terminal to which a dc power supply is connected, a 1 st inverter, a 2 nd inverter, and a switch. The 1 st inverter and the 2 nd inverter are connected with the input end. That is, the 1 st inverter and the 2 nd inverter are electrically connected. The 1 st inverter converts electric power of the dc power supply into driving electric power of the 1 st motor for traveling. The 2 nd inverter converts the electric power of the dc power supply into the driving electric power of the 2 nd motor. The switch can electrically disconnect the 2 nd inverter from the input and the 1 st inverter.)

1. A power control device for an electric vehicle is provided with:

the input end is connected with a direct current power supply;

a 1 st inverter connected to the input terminal, for converting electric power of the dc power supply into driving electric power of a 1 st motor for traveling;

a 2 nd inverter connected to the input terminal and configured to convert the electric power of the dc power supply into drive power for a 2 nd motor; and

a switch electrically disconnecting the 2 nd inverter from the input and the 1 st inverter.

2. The power control apparatus according to claim 1,

the maximum output current of the 2 nd inverter is 1/10 or less of the maximum output current of the 1 st inverter.

3. The power control device according to claim 1 or 2,

the 1 st inverter, the 2 nd inverter, and the switch are housed in 1 case.

4. The power control device according to any one of claims 1 to 3,

the switch is a fuse.

5. The power control device according to any one of claims 1 to 4,

the switch is mounted on a substrate on which a control circuit for controlling the 1 st inverter and the 2 nd inverter is mounted.

6. The power control device according to any one of claims 1 to 4,

the switch is embedded in a power line connecting a substrate on which a control circuit for controlling the 1 st inverter and the 2 nd inverter is mounted and the input terminal.

7. The power control device according to any one of claims 1 to 6,

the 2 nd motor is a motor that drives a hydraulic pump that controls a clutch between the 1 st motor and a drive wheel.

Technical Field

The technology disclosed in the present specification relates to a power control device that is mounted on an electric vehicle and converts electric power from a dc power supply into drive power for a motor for traveling. The "electric vehicle" in the present specification includes a hybrid vehicle including both a motor and an engine, and a fuel cell vehicle.

Background

The electric vehicle includes a power control device that converts electric power of a dc power supply into driving power of a motor for traveling. The main device of the power control apparatus is an inverter. In japanese patent laid-open publication No. 2015-023772, a power control device including 2 inverters is disclosed. The 1 st inverter supplies electric power to a motor for traveling. The 2 nd inverter supplies electric power to a motor of the oil pump.

Disclosure of Invention

An electric vehicle may include an electric motor in addition to a motor for traveling. In such a case, as disclosed in japanese patent application laid-open No. 2015-023772, an electric vehicle is provided with a power control device including 2 inverters. Hereinafter, for the sake of explanation, the motor for traveling will be referred to as a 1 st motor, and the other motor will be referred to as a 2 nd motor. An inverter that converts the electric power of the dc power supply into the driving power of the 1 st motor is referred to as a 1 st inverter, and an inverter that converts the electric power of the dc power supply into the driving power of the 2 nd motor is referred to as a 2 nd inverter.

When the 1 st inverter and the 2 nd inverter are electrically connected, if a short circuit occurs in the 2 nd inverter, not only the 2 nd inverter but also the 1 st inverter cannot be used. When the 1 st motor cannot be used, traveling by the 1 st motor cannot be performed. The present specification relates to a power control apparatus including 2 inverters, and provides a technique capable of using a 1 st inverter even when a short circuit occurs in the 2 nd inverter.

The power control device disclosed in the present specification includes an input terminal to which a dc power supply is connected, a 1 st inverter, a 2 nd inverter, and a switch. The 1 st inverter and the 2 nd inverter are connected with the input end. That is, the 1 st inverter and the 2 nd inverter are electrically connected. The 1 st inverter converts electric power of the dc power supply into driving electric power of the 1 st motor for traveling. The 2 nd inverter converts the electric power of the dc power supply into the driving electric power of the 2 nd motor. The switch can electrically disconnect the 2 nd inverter from the input and the 1 st inverter. The power control device can electrically disconnect the 2 nd inverter from the 1 st inverter and the input terminal by the switch when the 2 nd inverter is short-circuited. Therefore, the power control apparatus can use the 1 st inverter even if a short circuit occurs in the 2 nd inverter. An electric vehicle equipped with the power control device can travel with the 1 st motor even when a short circuit occurs in the 2 nd inverter. The switch may be any of a mechanical relay, a semiconductor switch, and a fuse.

Details and further improvements of the technology disclosed in the present specification will be described in the following "detailed description of the preferred embodiments".

Drawings

Fig. 1 is a block diagram of a drive system of an electric vehicle including a power control device of the embodiment.

Fig. 2 is a block diagram of a drive system of an electric vehicle including the power control device according to modification 1.

Fig. 3 is a block diagram of a drive system of an electric vehicle including the power control device of modification 2.

Detailed Description

(embodiment) referring to fig. 1, a power control device 10 of the embodiment will be described. Fig. 1 is a block diagram of a drive system of an electric vehicle 2 including a power control device 10. The electric vehicle 2 is a hybrid vehicle including a motor for traveling (the 1 st motor 31) and an engine 33. The 1 st motor 31 and the engine 33 are coupled to a gear train 34. The output shaft 35 of the gear set 34 is coupled to wheels 38 via a clutch 36 and a differential gear 37. The gear set 34 synthesizes the torques of the 1 st motor 31 and the engine 33, and transmits the synthesized torque to the output shaft 35.

The clutch 36 is a device that disconnects the wheels 38 from the 1 st motor 31 and the engine 33. The clutch 36 is hydraulically controlled. The 1 st hydraulic pump 41 and the 2 nd hydraulic pump 42 are coupled to the clutch 36 via an oil passage 43. The 1 st hydraulic pump 41 is driven by the engine 33. The 2 nd hydraulic pump 42 is driven by the 2 nd motor 32. The clutch 36 can be controlled if either one of the 1 st hydraulic pump 41 (engine 33) and the 2 nd hydraulic pump 42 (2 nd motor 32) is operated.

Both the 1 st motor 31 and the 2 nd motor 32 receive electric power from the power control device 10. The power control device 10 converts the electric power of the battery 4 into drive power for each of the 1 st motor 31 and the 2 nd motor 32. The output voltage of the battery 4 is 100 volts or more, and the maximum output power exceeds 10 kw. The 1 st motor 31 is a motor that drives the wheels 38, and its maximum output current exceeds 100 amperes. On the other hand, the 2 nd motor 32 is a motor that drives the 2 nd hydraulic pump 42, and the maximum output current thereof is, for example, 10 amperes or less. In other words, the maximum output current of the 2 nd motor 32 is 1/10 or less of the maximum output current of the 1 st motor 31.

The power control device 10 includes a 1 st inverter 11, a 2 nd inverter 12, and a circuit board 13. The 1 st inverter 11 converts the electric power of the battery 4 into the driving electric power of the 1 st motor 31. The 2 nd inverter 12 converts the electric power of the battery 4 into the driving electric power of the 2 nd motor 32. The 1 st motor 31 and the 2 nd motor 32 are both three-phase ac motors. Both the 1 st inverter 11 and the 2 nd inverter 12 are devices that convert dc power into ac power.

As described above, the maximum output current of the 2 nd motor 32 is 1/10 or less of the maximum output current of the 1 st motor 31. Therefore, the maximum output current of the 2 nd inverter 12 is 1/10 or less of the maximum output current of the 1 st inverter 11.

The maximum output current of the 1 st inverter 11 is larger than the maximum output current of the 2 nd inverter 12. The heat generation amount of the 1 st inverter 11 is larger than the heat generation amount of the 2 nd inverter 12. Although not shown, the 1 st inverter 11 is provided with a cooler. For example, the 1 st inverter 11 includes a plurality of power modules accommodating switching elements for power conversion and a plurality of coolers. The plurality of power modules and the plurality of coolers are alternately stacked one by one. Both sides of each power module are connected to a cooler. The detailed structure of the 1 st inverter 11 will not be described.

A control circuit 15 that controls the 1 st inverter 11 and the 2 nd inverter 12 is mounted to the circuit substrate 13. In addition, the dashed arrow line of fig. 1 indicates the flow of the signal. The 2 nd inverter 12 generates a small amount of heat because the maximum output current is small. Therefore, the 2 nd inverter 12 is directly fixed to the circuit substrate 13. Further, the circuit substrate 13 is fixed to a housing 19 of the power control device 10. On the other hand, since the heat generation amount is large, the 1 st inverter 11 is directly fixed to the case 19 independently of the circuit board 13. The detailed structure of the 2 nd inverter 12 will not be described.

The 1 st inverter 11 is connected to the input terminal 16 of the power control device 10 via a main power line 21. The 2 nd inverter 12 is connected to the input terminal 16 via a sub power line 22 and a main power line 21. The input 16 of the power control device 10 is connected to the battery 4. The sub power line 22 is connected to the middle of the main power line 21. As described above, the maximum output current of the 2 nd inverter 12 is 1/10 or less of the maximum output current of the 1 st inverter 11. Therefore, the allowable current of the sub power line 22 may be 1/10 or less of the allowable current of the main power line 21, and the thickness of the sub power line 22 may be smaller than the thickness of the main power line 21.

A smoothing capacitor 17 is connected between the positive electrode line and the negative electrode line of the main power line 21. The smoothing capacitor 17 suppresses the ripple of the current flowing through the main power line 21.

The sub power line 22 is connected to the 2 nd inverter 12 via the circuit board 13. A fuse 14 is mounted on the circuit board 13. The fuse 14 is embedded in the secondary power line 22. The fuse 14 is blown when an overcurrent flows, and electrically disconnects the 2 nd inverter 12 from the 1 st inverter 11 and the input terminal 16 (i.e., the battery 4).

A typical case where an overcurrent flows in the 2 nd inverter 12 is when a short circuit occurs in the 2 nd inverter 12 or the 2 nd motor 32. When the 2 nd inverter 12 or the 2 nd motor 32 in which the short circuit occurs is connected to the 1 st inverter 11 (and the input terminal 16) as it is, not only the 2 nd inverter 12 but also the 1 st inverter 11 cannot be used. When the 1 st motor 31 cannot be used, the 1 st motor 31 cannot drive the wheels 38. That is, the electric vehicle 2 cannot travel using the 1 st motor 31. When the fuse 14 is blown and the 2 nd inverter 12 or the 2 nd motor 32 in which a short circuit occurs is disconnected from the 1 st inverter 11 (and the input terminal 16), the 1 st inverter 11 can be used. That is, by providing the fuse 14, the 1 st inverter 11 (the 1 st motor 31) can be used even when a failure occurs in the 2 nd inverter 12 or the 2 nd motor 32.

Further, a fuse 5 is also connected between the battery 4 and the input terminal 16. The fuse 5 is blown when an overcurrent flows through the 1 st inverter 11. Since the maximum output current of the 2 nd inverter 12 (the allowable current of the sub power line 22) is 1/10 or less of the maximum output current of the 1 st inverter 11 (the allowable current of the main power line 21), the allowable current of the fuse 14 may be 1/10 or less of the allowable current of the fuse 5. When a short circuit occurs in the 2 nd inverter 12 (2 nd motor 32), the fuse 14 is blown before the fuse 5. Therefore, after the short circuit is generated in the 2 nd inverter 12 (the 2 nd motor 32), the fuse 5 is not blown, so the 1 st inverter 11 can be continuously supplied with electric power from the battery 4.

When a short circuit occurs in the 2 nd inverter 12 or the 2 nd motor 32, the fuse 14 electrically disconnects them from the 1 st inverter 11 and the input terminal 16, and protects the 1 st inverter 11.

As described above, the 2 nd motor 32 drives the 2 nd hydraulic pump 42. The clutch 36 can be controlled if either one of the 1 st hydraulic pump 41 and the 2 nd hydraulic pump 42 is operated. When the 2 nd motor 32 (the 2 nd hydraulic pump 42) cannot be used, the 1 st hydraulic pump 41 is driven by the engine 33, whereby the clutch 36 can be controlled.

Next, other features of the power control device 10 of the embodiment will be described. The fuse 14 is mounted to a circuit substrate 13 on which a control circuit 15 that controls the 1 st inverter 11 and the 2 nd inverter 12 is mounted. The 2 nd inverter 12 is fixed to the circuit board 13. By mounting the fuse 14 that electrically opens the 2 nd inverter 12 to the circuit substrate 13, the work and cost of embedding the fuse 14 are suppressed.

(modification 1) fig. 2 shows a power control device 10a of modification 1. The power control device 10a includes a relay switch 14a instead of the fuse 14. The relay switch 14a is mounted on the circuit board 13. The relay switch 14a is controlled by a control circuit 15 mounted on the circuit board 13. When a short circuit occurs in inverter 2 12 or motor 2 32, control circuit 15 opens relay switch 14a to electrically disconnect inverter 2 and motor 2 from inverter 1 11 and input terminal 16. The relay switch 14a also has the same advantages as the fuse 14 of the power control device 10 of the embodiment. The relay switch 14a is preferably of a normally open type.

(modification 2) fig. 3 shows a power control device 10b of modification 2. In the power control device 10b, the fuse 14 is not fixed to the circuit substrate 13, but is embedded in the middle of the sub power line 22. Instead of the fuse 14, a relay switch may be embedded in the sub power line 22.

The features of the power control device 10(10a, 10b) are described below. The power control device 10(10a, 10b) includes an input terminal 16, a 1 st inverter 11, a 2 nd inverter 12, and a fuse 14. The input 16 is connected to the battery 4. The input terminal 16 is connected to the 1 st inverter 11 and the 2 nd inverter 12. The 1 st inverter 11 converts the electric power of the battery 4 into driving electric power of a motor for traveling (the 1 st motor 31). The 2 nd inverter converts the electric power of the battery 4 into the driving electric power of the 2 nd motor. The fuse 14 is a switch for electrically disconnecting the 2 nd inverter 12 from the input terminal 16 and the 1 st inverter 11. The fuse 14 opens the 2 nd inverter 12 that is short-circuited (failed). Even if a short circuit (failure) occurs in the 2 nd inverter 12, the 1 st inverter 11 can drive the 1 st motor 31.

The maximum output current of the 2 nd inverter 12 is 1/10 or less of the maximum output current of the 1 st inverter 11. The power supplied to the 1 st inverter 11 does not flow through the fuse 14. The allowable current of the fuse 14 may be smaller than the maximum output current of the 1 st inverter 11 (the allowable current of the main power line 21). The fuse 14 with a small allowable current can be mounted on the circuit board 13. In the circuit board 13, a control circuit 15 that controls the 1 st inverter 11 and the 2 nd inverter 12 is also mounted.

The 1 st inverter 11, the 2 nd inverter 12, and the fuse 14 are housed in a case 19 of the power control device 10(10a, 10 b).

The 2 nd motor 32 driven by the 2 nd inverter 12 drives a hydraulic pump (2 nd hydraulic pump 42) that controls the clutch 36 between the 1 st motor 31 and the wheels 38.

In the power control device 10a, a relay switch 14a is embedded in the circuit board 13 instead of the fuse 14. In the power control device 10b, the fuse 14 is not mounted on the circuit board 13, but is embedded in the sub power line 22 connecting the input terminal 16 and the 2 nd inverter 12.

Attention is paid to the techniques explained in the embodiments and the modifications thereof. The switch that disconnects the 2 nd inverter 12 from the 1 st inverter 11 and the input terminal 16 may be any of a fuse, a mechanical relay switch, and a semiconductor switch. Switches for disconnecting the 2 nd inverter 12 from the 1 st inverter 11 and the input terminal 16 may be attached to a terminal block of the fixed input terminal 16.

The 2 nd motor driven by the 2 nd inverter 12 may be a motor that operates a device other than the hydraulic pump. The dc power supply connected to input 16 may also be a fuel cell.

The electric power control device disclosed in the present specification is applicable to an electric vehicle having no engine, and an electric vehicle having a fuel cell as a power source, in addition to a hybrid vehicle.

While specific examples of the present invention have been described in detail, these are merely illustrative and do not limit the scope of the claims. The techniques described in the claims include examples in which the specific examples illustrated above are variously modified and changed. The technical elements described in the present specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations recited in the claims at the time of filing. Further, the techniques exemplified in the present specification or the drawings can achieve a plurality of objects at the same time, and achieving one of the objects has technical utility.