electric vehicles

Abstract

This system allows for emergency movement in the event of a malfunction in the first inverter unit or other components. [Solution] The electric vehicle comprises a battery system having first and second batteries, a series line, a parallel line, and first to fourth relays, a motor, and a power converter having first and second inverter sections and first and second changeover switches. If an abnormality occurs in at least one of the first upper arms of each phase of the first inverter section, the electric vehicle turns on the second relay, turns off the first, third, and fourth relays, turns off the first and second changeover switches, neutralizes the other end of the three-phase open winding using the second inverter, and drives the motor by switching the intermediate potential switches of each phase and the first lower arms of each phase.

Description

Technical Field

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[0001] This disclosure relates to electric vehicles.

Background Art

[0002] Conventionally, an electric vehicle has been proposed that includes a battery, a traveling motor having a three-phase open winding, a first inverter unit connected to a positive line and a negative line to which the battery is connected and connected to one end side of the three-phase open winding, and a second inverter unit connected to the opposite side of the battery with respect to the first inverter unit among the positive line and the negative line and connected to the other end side of the three-phase open winding, and first and second switching switches provided between the first and second inverter units among the positive line and the negative line (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] <00000​​​​​​​The electric vehicle of this disclosure employs the following means to achieve the main objective described above. Each of the first, second, and third electric vehicles of this disclosure comprises a battery system having a first battery with a first positive terminal connected to a positive line, a second battery with a second negative terminal connected to a negative line, a first relay provided on the positive line, a second relay provided on the negative line, a third relay provided on a series line connecting the first negative terminal of the first battery and the second positive terminal of the second battery, and a fourth relay provided on a parallel line connecting the series line on the side of the negative line furthest from the second battery than the third relay, a motor for driving with a three-phase open winding, a first inverter unit connected to the positive line and the negative line and connected to one end of the three-phase open winding, a second inverter unit connected to the side of the positive line and the negative line furthest from the battery system than the first inverter unit and connected to the other end of the three-phase open winding, and the positive line and the negative line An electric vehicle comprising a power converter having first and second changeover switches provided between first and second inverter sections, and a control device, wherein the first inverter section has a first upper arm and a first lower arm for each phase, each connected in series with respect to the positive and negative lines, and the connection points of each phase are connected to one end of the open winding, first and second capacitors, each connected in series with respect to the positive and negative lines, and the connection points of each phase are connected to the second battery side of the series line than the third relay, and intermediate potential switches for each phase provided on the intermediate potential lines of each phase that connect the connection points of the first upper arm and first lower arm of each phase to the connection points of the first and second capacitors, respectively, and the second inverter section has a second upper arm and a second lower arm for each phase, each connected in series with respect to

[0006] Furthermore, in the first electric vehicle of the present disclosure, if an abnormality occurs in at least one of the first upper arms of each phase, the control device turns on the second relay, turns off the first, third, and fourth relays, turns off the first and second changeover switches, neutralizes the other end of the three-phase open winding with the second inverter, and drives the motor by switching the intermediate potential switches of each phase and the first lower arms of each phase. If an abnormality occurs in at least one of the first lower arms of each phase, the control device turns on the first and third relays, turns off the second and fourth relays, turns off the first and second changeover switches, neutralizes the other end of the three-phase open winding with the second inverter, and drives the motor by switching the first upper arms of each phase and the intermediate potential switches of each phase. In this way, if an abnormality occurs in at least one of the first upper arms of each phase, or if an abnormality occurs in at least one of the first lower arms of each phase, the robot can perform a retraction maneuver.

[0007] In the second electric vehicle of this disclosure, the control device turns on the first and fourth relays, turns off the second and third relays, turns on the first and second changeover switches, turns off the first upper and first lower arms of each phase, turns on the intermediate potential switches of each phase, and drives the motor by switching the second inverter unit. In this way, the vehicle can perform retraction driving when an open circuit occurs in at least one of the first upper and first lower arms of each phase or when a short circuit occurs in at least one of the intermediate potential switches of each phase.

[0008] In the third electric vehicle of this disclosure, the control device turns on the first, second, and third relays, turns off the fourth relay, turns on the first and second changeover switches, turns off the first upper arms of each phase, turns on the first lower arms of each phase, turns off the intermediate potential switches of each phase, and drives the motor by switching the second inverter unit. In this way, the vehicle can perform retraction driving when an open fault occurs in at least one of the first upper arms of each phase or when a short fault occurs in at least one of the first lower arms of each phase. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the general configuration of the electric vehicle 10 according to the embodiment of the disclosure. [Figure 2] This is an explanatory diagram showing an example of a train's emergency maneuver in the event of a malfunction in transistor T11. [Figure 3] This is an explanatory diagram showing an example of a train taking a detour when a malfunction occurs in transistor T14. [Figure 4] This is an explanatory diagram showing an example of a train's emergency maneuver when an open circuit abnormality occurs in transistor T11. [Figure 5] This is an explanatory diagram illustrating an example of a train's emergency exit procedure in the event of a short circuit in transistor T14. [Modes for carrying out the invention]

[0010] Embodiments for implementing this disclosure will be described with reference to the drawings. Figure 1 is a schematic diagram showing the general configuration of an electric vehicle 10 according to an embodiment of this disclosure. As shown in the figure, the electric vehicle 10 of the embodiment comprises a battery system 11, a motor 28, a power converter 29, and an electronic control unit (hereinafter referred to as "ECU") 50 (control device).

[0011] The battery system 11 comprises first and second batteries 12 and 13, and first to fourth relays R1 to R4. The first and second batteries 12 and 13 are configured as lithium-ion secondary batteries or nickel-metal hydride secondary batteries, respectively, with a rated voltage of, for example, a first voltage Vs1 (for example, several hundred volts). In this embodiment, the first and second batteries 12 and 13 are of the same specifications.

[0012] The first positive terminal of the first battery 12 is connected to the positive line 21. The second negative terminal of the second battery 13 is connected to the negative line 23. The first relay R1 is provided on the positive line 21. The second relay R2 is provided on the negative line 23. The third relay R3 is provided on the series line 15 that connects the first negative terminal of the first battery 12 and the second positive terminal of the second battery 13. The fourth relay R4 is provided on the parallel line 16 that connects the series line 15 on the side of the first battery 12 that is further from the third relay R3 and the negative line 23 that is further from the second relay and further from the second battery 13.

[0013] The motor 28 is configured as a three-phase AC motor and comprises a rotor with permanent magnets embedded in its rotor core and a stator with three-phase (U-phase, V-phase, W-phase) coils (open windings) wound around its stator core. The rotor is connected to a drive shaft which is linked to the drive wheels via a differential gear.

[0014] The power converter 29 comprises a first inverter unit 30, a second inverter unit 36, and first and second changeover switches 40a and 40b. The first inverter unit 30 is connected to the positive electrode line 21, the intermediate potential line 22, and the negative electrode line 23, and is also connected to one end of the three-phase coil of the motor 28. The first inverter unit 30 is equipped with a T-type three-level inverter, and specifically comprises six transistors T11 to T16, six diodes D11 to D16 connected in parallel to the six transistors T11 to T16, two capacitors 31 and 32, three-phase (U-phase, V-phase, W-phase) intermediate potential lines 33u, 33v, and 33w, and three-phase intermediate potential switches 34u, 34v, and 34w. Transistors T11 to T16 are, for example, MOSFETs and IGBTs. Transistors T11 to T16 are arranged in pairs, with two transistors acting as the source and two as the sink for the positive line 21 and the negative line 23. The connection points of transistors T11 and T14, T12 and T15, and T13 and T16 are connected to one end of the U-phase, V-phase, and W-phase coils of the motor 28, respectively. Hereafter, transistors T11 to T13 may be referred to as the "first upper arm," and transistors T14 to T16 as the "first lower arm." Capacitors 31 and 32 are connected in series with respect to the positive line 21 and the negative line 23 in this order. Capacitors 31 and 32 are of the same specifications. The connection points of capacitors 31 and 32 are connected to the second battery 13 side of relay R3 on the series line 15 via the intermediate potential line 22. The three-phase intermediate potential lines 33u, 33v, and 33w connect the connection points of transistors T11 and T14, T12 and T15, T13 and T16, and capacitors 31 and 32, respectively. The three-phase intermediate potential switches 34u, 34v, and 34w are provided on the three-phase intermediate potential lines 33u, 33v, and 33w, respectively. The three-phase intermediate potential switches 34u, 34v, and 34w are, for example, semiconductor switches, specifically wide-bandgap semiconductor switches using gallium nitride (GaN) or silicon carbide (SiC).The intermediate potential switch 26u may be constructed, for example, by using two sets of transistors and diodes connected in parallel thereto, with the diodes connected in series so that they are facing in opposite directions. The intermediate potential switches 26v and 26w are constructed similarly.

[0015] The second inverter unit 36 ​​is connected to the positive electrode line 21 and the negative electrode line 23 on the side further from the battery system 11 than the first inverter unit 30. The second inverter unit 36 ​​is equipped with a two-level inverter and specifically comprises six transistors T21 to T26, six diodes D21 to D26 connected in parallel to each of the six transistors T21 to T26, and a capacitor 37. Transistors T21 to T26 are, for example, MOSFETs or IGBTs. Transistors T21 to T26 are arranged in pairs, with two on each side, acting as the source and sink sides with respect to the positive electrode line 21 and the negative electrode line 23. The connection points of transistors T21 and T24, T22 and T25, and T23 and T26 are connected to the other ends of the U-phase, V-phase, and W-phase coils of the motor 28, respectively. Hereafter, transistors T21-T23 may be referred to as the "second upper arm," and transistors T24-T26 as the "second lower arm." Capacitor 37 is connected to the positive line 21 and the negative line 23.

[0016] The first and second changeover switches 40a and 40b are provided between the first and second inverter sections 30 and 36 of the positive line 21 and the negative line 23, respectively. The first and second changeover switches 40a and 40b are, for example, semiconductor switches. The first changeover switch 40a may be configured, for example, using two sets of transistors and diodes connected in parallel thereto, connected in series so that the diodes are facing in opposite directions. The second changeover switch 40b is configured similarly.

[0017] The ECU50 is equipped with a microcomputer having a CPU, ROM, RAM, flash memory, input / output ports, and communication ports, as well as various drive circuits and various logic ICs. Signals from various sensors are input to the ECU50. For example, the ECU50 receives the voltage Vb1 of the first battery 12 from the voltage sensor 12V, the voltage Vb2 of the second battery 13 from the voltage sensor 13V, the current Ip1 of the positive electrode line 21 from the current sensor 21i, and the current Ip2 of the intermediate potential line 22 from the current sensor 22i. The ECU50 also receives the rotational position θm of the rotor of the motor 28 from the rotational position sensor 28a, and the phase currents Iu, Iv, and Iw of each phase of the motor 28 from the current sensors 28u, 28V, and 28W. The ECU50 also receives the voltage Vc1 of the capacitor 31 from the voltage sensor 31V, the voltage Vc2 of the capacitor 32 from the voltage sensor 32V, and the voltage Vc3 of the capacitor 37 from the voltage sensor 37V. The ECU50 also receives inputs from the power switch (on / off signal), the shift position SP (shift lever operation position from the shift position sensor), the accelerator pedal position Acc (accelerator pedal depression amount from the accelerator pedal position sensor), the brake pedal position BP (brake pedal depression amount from the brake pedal position sensor), and the vehicle speed V (vehicle speed sensor).

[0018] The ECU 50 calculates the charge levels SOC1 and SOC2 of the first and second batteries 12 and 13, and also calculates the electrical angle θe and rotational speed Nm of the motor 28. The charge levels SOC1 and SOC2 of the first and second batteries 12 and 13 are calculated based on the states of the first to fourth relays R1 to R4 and the currents Ip1 and Ip2 of the positive electrode line 21 and the intermediate potential line 22. The electrical angle θe and rotational speed Nm of the motor 28 are calculated based on the rotational position θm of the motor 28's rotor. Various control signals are output from the ECU 50. For example, the ECU 50 outputs control signals to the battery system 11 (1st to 4th relays R1 to R4), the first inverter unit 30 (transistors T11 to T16 and 3-phase intermediate potential switches 34u, 34v, 34w), the second inverter unit 36 ​​(transistors T21 to T26), and the first and second changeover switches 40a and 40b.

[0019] In the electric vehicle 10 of the embodiment, the ECU 50 sets the required torque Td* for running based on the accelerator opening Acc and the vehicle speed V, sets the torque command Tm* of the motor 28 so as to run with the set required torque Td*, and based on the set torque command Tm*, basically, one of the two-level H drive mode, two-level Y drive mode, and three-level Y drive mode is selected and executed to perform running. Here, H drive means driving the motor 28 by switching the first and second inverter units 30 and 36, and Y drive means neutralizing the side of the second inverter unit 36 (the other end side of the three-phase coil) from the motor 28 and driving the motor 28 by switching the first inverter unit 30. In any of the two-level H drive mode, two-level Y drive mode, and three-level Y drive mode, for the battery system 11, the first, second, and third relays R1, R2, and R3 are turned on and the fourth relay R4 is turned off. That is, the first and second batteries 12 and 13 are connected in series.

[0020] The two-level H drive mode will be described. In this mode, the first and second changeover switches 40a and 40b are turned on. Also, for the first and second inverter units 30 and 36, the three-phase intermediate potential switches 34u, 34v, and 34w are turned off and the transistors T11 to T16, T21 to T26 are driven by switching. In this way, the potentials of one end side and the other end side of the motor 28 are switched at two levels (the potential of the positive electrode line 21, the potential of the negative electrode line 23).

[0021] The 2-level Y drive mode will be described. In this mode, the first and second switching switches 40a and 40b are turned off. Also, for the second inverter section 36, one of the three-phase second upper arm (transistors T21 to T23) and the three-phase second lower arm (transistors T24 to T26) is turned on and the other is turned off. As a result, the side of the second inverter section 36 (the other end side of the three-phase coil) from the motor 28 is neutralized. Since the first and second switching switches 40a and 40b are in the off state, all of the transitors T21 to T26 may be turned on. Further, for the first inverter section 30, the three-phase intermediate potential switches 34u, 34v, and 34w are turned off and the transitors T11 to T16 are driven by switching. In this way, the potential of one end side of the motor 28 is switched at two levels (the potential of the positive line 21 and the potential of the negative line 23).

[0022] The 3-level Y drive mode will be described. This mode is different from the 2-level Y drive mode in that, for the first inverter section 30, the three-phase intermediate potential switches 34u, 34v, and 34w and the transitors T11 to T16 are driven by switching. In this way, the potential of one end side of the motor 28 is switched at three levels (the potential of the positive line 21, the potential of the connection point of the capacitors 31 and 32, and the potential of the negative line 23).

[0023] Next, the operation of the electric vehicle 10 of the embodiment, particularly the operation when an abnormality occurs in the power conversion device 29 and retreat running is performed, will be described. First, the case where an abnormality occurs in the first and second switching switches 40a and 40b will be described. When an open-circuit abnormality occurs in at least one of the first and second switching switches 40a and 40b, the first and second switching switches 40a and 40b are turned off. As a result, the above-described 2-level Y drive mode or 3-level Y drive mode can be executed to perform retreat running. Also, when a short-circuit abnormality occurs in at least one of the first and second switching switches 40a and 40b, the first and second switching switches 40a and 40b are turned on. As a result, the 2-level H drive mode can be executed to perform retreat running.

[0024] Next, we will explain what happens when an abnormality occurs in the second inverter unit 36. If a short circuit occurs in at least one of the 3-phase second upper arms (transistors T21 to T23) of the second inverter unit 36, or if an open circuit occurs in at least one of the 3-phase second lower arms (transistors T24 to T26), the first and second changeover switches 40a and 40b are turned off, the 3-phase second upper arms are turned on, and the 3-phase second lower arms are turned off. Furthermore, if an open circuit occurs in at least one of the 3-phase second upper arms, or if a short circuit occurs in at least one of the 3-phase second lower arms, the first and second changeover switches 40a and 40b are turned off, the 3-phase second upper arms are turned off, and the 3-phase second lower arms are turned on. With these settings, the 2-level Y drive mode or 3-level Y drive mode can be executed to perform retraction travel.

[0025] Next, we will explain what happens when an abnormality occurs in the first inverter unit 30. First, we will explain what happens when an abnormality (short circuit abnormality, open circuit abnormality) occurs in at least one of the three phases of the first upper arm (transistors T11 to T13) of the first inverter unit 30. Figure 2 is an explanatory diagram showing an example of retraction when an abnormality occurs in transistor T11. As shown in the figure, when an abnormality occurs in transistor T11, the first, third, and fourth relays R1, R3, and R4 are turned off and the second relay R2 is turned on. As a result, only the second battery 13 of the first and second batteries 12 and 13 is connected to the first inverter unit 30, and the three phases of the first upper arm (transistors T11 to T13) connected to the positive electrode line 21 are disconnected from the battery system 11 (first battery 12). Also, similar to the two-level Y drive mode and three-level Y drive mode described above, the first and second changeover switches 40a and 40b are turned off and the second inverter unit 36 ​​side is made the neutral point relative to the motor 28. In Figure 2, the second upper arm of the 3-phase system (transistors T21-T23) is turned ON, while the second lower arm of the 3-phase system (transistors T24-T26) is turned OFF. Furthermore, transistors T12 and T13 are turned OFF. Then, the 3-phase intermediate potential switches 34u, 34v, and 34w, and transistors T14-T16 are switched on. As a result, the 3-phase intermediate potential switches 34u, 34v, and 34w function as substitutes for the first upper arm of the 3-phase system (transistors T11-T13), allowing the first inverter unit 30 to operate as a 2-level inverter. In this way, the vehicle can perform emergency movement using power from the second battery 13. Here, we have explained the case where an abnormality occurs in transistor T11, but the same considerations can be applied if an abnormality occurs in either transistor T12 or T13, or if multiple abnormalities occur in transistors T11-T13.

[0026] Next, we will explain the case where an abnormality (short circuit abnormality, open circuit abnormality) occurs in at least one of the three phases of the first lower arm (transistors T14 to T16) of the first inverter unit 30. Figure 3 is an explanatory diagram showing an example of retraction when an abnormality occurs in transistor T14. As shown in the figure, when a short circuit abnormality occurs in transistor T14, the second and fourth relays R2 and R4 are turned off and the first and third relays R1 and R3 are turned on. As a result, only the first battery 12 of the first and second batteries 12 and 13 is connected to the first inverter unit 30 side, and the three phases of the first lower arm (transistors T14 to T16) connected to the negative electrode line 23 are disconnected from the battery system 11 (second battery 13). Also, similar to the two-level Y drive mode and three-level Y drive mode described above, the first and second changeover switches 40a and 40b are turned off and the second inverter unit 36 ​​side is made the neutral point relative to the motor 28. In Figure 3, the second upper arm of the 3-phase system (transistors T21-T23) is turned ON, while the second lower arm of the 3-phase system (transistors T24-T26) is turned OFF. Furthermore, transistors T15 and T16 are turned OFF. Then, the 3-phase intermediate potential switches 34u, 34v, and 34w, and transistors T11-T13 are switched on. As a result, the 3-phase intermediate potential switches 34u, 34v, and 34w function as substitutes for the first lower arm of the 3-phase system (transistors T14-T16), allowing the first inverter unit 30 to operate as a 2-level inverter. In this way, the vehicle can perform emergency movement using power from the first battery 12. Here, we have explained the case where an abnormality occurs in transistor T14, but the same considerations can be applied if an abnormality occurs in either transistor T15 or T16, or if multiple abnormalities occur in transistors T14-T16.

[0027] Next, we will explain the case where a short circuit occurs in at least one of the three-phase intermediate potential switches 34u, 34v, and 34w. Figure 4 is an explanatory diagram showing an example of safeguard operation when a short circuit occurs in at least one of the three-phase intermediate potential switches 34u, 34v, and 34w. As shown in the figure, when a short circuit occurs in at least one of the three-phase intermediate potential switches 34u, 34v, and 34w, the first and fourth relays R1 and R4 are turned ON, the second and third relays R2 and R3 are turned OFF, transistors T12 to T16 are turned OFF, and the three-phase intermediate potential switches 34u, 34v, and 34w are turned ON. As a result, the first inverter section 30 side is neutralized from the motor 28. In addition, the first and second changeover switches 40a and 40b are turned ON. Furthermore, transistors T21 to T26 of the second inverter section 36 are switched on. In this way, the vehicle can perform emergency maneuvers using power from the first battery 12. Alternatively, instead of turning off the second and fourth relays R2 and R4 and turning on the first and third relays R1 and R3, the fourth relay R4 may be turned off and the first, second, and third relays R1, R2, and R3 may be turned on.

[0028] In addition, the case where an open circuit abnormality occurs in at least one of the three-phase intermediate potential switches 34u, 34v, and 34w will be explained. In this case, the three-phase intermediate potential switches 34u, 34v, and 34w will be turned off. This will allow the vehicle to perform evasive maneuvers by executing the 2-level H drive mode or the 2-level Y drive mode.

[0029] In the embodiment described above, if an abnormality (short circuit or open circuit) occurs in at least one of the three phases of the first upper arm (transistors T11 to T13) of the first inverter unit 30, the first, third, and fourth relays R1, R3, and R4 are turned off, the second relay R2 is turned on, the first and second changeover switches 40a and 40b are turned off, the second inverter unit 36 ​​side of the motor 28 is made the neutral point, and the three phase intermediate potential switches 34u, 34v, and 34w and transistors T14 to T16 are switched on (see Figure 2). Furthermore, if an abnormality (short circuit or open circuit) occurs in at least one of the three phases of the first lower arm (transistors T14-T16) of the first inverter unit 30, the second and fourth relays R2 and R4 are turned off, the first and third relays R1 and R3 are turned on, the first and second changeover switches 40a and 40b are turned off, the second inverter unit 36 ​​side of the motor 28 is made the neutral point, and the three phase intermediate potential switches 34u, 34v, 34w and transistors T11-T13 are switched on (see Figure 3). However, if an open circuit abnormality occurs in at least one of the three phases of the first upper arm and the three phases of the first lower arm, the control may be the same as when a short circuit abnormality occurs in at least one of the three phases of the intermediate potential switches 34u, 34v, 34w (see Figure 4).

[0030] In the embodiment described above, if an abnormality (short circuit or open circuit) occurs in at least one of the three phases of the first lower arm (transistors T14 to T16) of the first inverter unit 30, the second and fourth relays R2 and R4 are turned off, the first and third relays R1 and R3 are turned on, the first and second changeover switches 40a and 40b are turned off, the second inverter unit 36 ​​side of the motor 28 is made the neutral point, and the three phase intermediate potential switches 34u, 34v, 34w and transistors T11 to T13 are switched on (see Figure 3). However, if a short circuit occurs in the three phases of the first lower arm of the first inverter unit 30, the following control may be performed.

[0031] Figure 5 is an explanatory diagram showing an example of emergency movement in the event of a short circuit in transistor T14. As shown in the figure, when a short circuit occurs in transistor T14, transistors T15 and T16 are turned ON, and transistors T11 to T13 are turned OFF. In addition, the first, second, and third relays R1, R2, and R3 are turned ON, the fourth relay R4 is turned OFF, and the three-phase intermediate potential switches 34u, 34v, and 34w are turned OFF. As a result, the first inverter section 30 side of the motor 28 becomes the neutral point. However, this neutral point is connected to the negative electrode line 23. Then, transistors T21 to T26 of the second inverter section 36 are switched on. In this way, emergency movement can be performed using power from the first and second batteries 12 and 13. Here, we have explained the case where a short-circuit anomaly occurs in transistor T14, but the same considerations can be applied if a short-circuit anomaly occurs in either transistor T15 or T16, or if multiple short-circuit anomalies occur in transistors T14 to T16. In addition to or instead of these, the same considerations can be applied if an open-circuit anomaly occurs in at least one of transistors T11 to T13.

[0032] Although the embodiments for implementing this disclosure have been described above, this disclosure is not limited in any way to these embodiments, and it is of course possible to implement it in various forms without departing from the gist of this disclosure. [Industrial applicability]

[0033] This disclosure can be used in industries such as electric vehicle manufacturing. [Explanation of symbols]

[0034] 10 Electric vehicle, 11 Battery system, 12,13 First and second batteries, 15 Series line, 16 Parallel line, 21 Positive line, 22 Intermediate potential line, 23 Negative line, 26 Power converter, 26u, 26v, 26w Intermediate potential switch, 28 Motor, 30, 36 First and second inverter section, 31, 32, 37 Capacitors, 33u, 33v, 33w Intermediate potential line, 34u, 34v, 34w Intermediate potential switch, 40a, 40b First and second changeover switch, 50 ECU, D11~D16, D21~D26 Diodes, R1~R4 First~Fourth relays, T11~T16, T21~T26 Transistors.

Claims

1. A battery system comprising: a first battery whose first positive terminal is connected to a positive line; a second battery whose second negative terminal is connected to a negative line; a first relay provided on the positive line; a second relay provided on the negative line; a third relay provided on a series line connecting the first negative terminal of the first battery and the second positive terminal of the second battery; and a fourth relay provided on a parallel line connecting the series line on the side of the series line closer to the first battery than the third relay and the negative line further from the second battery than the second relay; A motor for traction having a three-phase open winding, A power converter comprising: a first inverter unit connected to the positive electrode line and the negative electrode line and connected to one end of the three-phase open winding; a second inverter unit connected to the positive electrode line and the negative electrode line on a side further from the battery system than the first inverter unit and connected to the other end of the three-phase open winding; and first and second changeover switches provided between the first and second inverter units of the positive electrode line and the negative electrode line. Control device and An electric vehicle equipped with, The first inverter unit includes a first upper arm and a first lower arm for each phase, each connected in series with respect to the positive and negative lines, with their connection points connected to one end of the open winding; first and second capacitors, each connected in series with respect to the positive and negative lines, with their connection points connected to the second battery side of the series line compared to the third relay; and intermediate potential switches for each phase, each provided on the intermediate potential line connecting the connection points of the first upper and first lower arms of each phase to the connection points of the first and second capacitors, respectively. The second inverter section has a second upper arm and a second lower arm for each phase, which are connected in series with respect to the positive electrode line and the negative electrode line, and whose connection points are connected to the other end of the open winding. The control device is If an abnormality occurs in at least one of the first upper arms of each of the aforementioned phases, the second relay is turned ON, the first, third, and fourth relays are turned OFF, the first and second changeover switches are turned OFF, the other end of the three-phase open winding is neutralized by the second inverter, and the motor is driven by the switching of the intermediate potential switches of each phase and the first lower arms of each phase. If an abnormality occurs in at least one of the first lower arms of each phase, the first and third relays are turned ON, the second and fourth relays are turned OFF, the first and second changeover switches are turned OFF, the other end of the three-phase open winding is neutralized by the second inverter, and the motor is driven by switching the first upper arms of each phase and the intermediate potential switches of each phase. Electric car.

2. A battery system comprising: a first battery whose first positive terminal is connected to a positive line; a second battery whose second negative terminal is connected to a negative line; a first relay provided on the positive line; a second relay provided on the negative line; a third relay provided on a series line connecting the first negative terminal of the first battery and the second positive terminal of the second battery; and a fourth relay provided on a parallel line connecting the series line on the side of the series line closer to the first battery than the third relay and the negative line further from the second battery than the second relay; A motor for traction having a three-phase open winding, A power converter comprising: a first inverter unit connected to the positive electrode line and the negative electrode line and connected to one end of the three-phase open winding; a second inverter unit connected to the positive electrode line and the negative electrode line on a side further from the battery system than the first inverter unit and connected to the other end of the three-phase open winding; and first and second changeover switches provided between the first and second inverter units of the positive electrode line and the negative electrode line. Control device and An electric vehicle equipped with, The first inverter unit includes a first upper arm and a first lower arm for each phase, each connected in series with respect to the positive and negative lines, with their connection points connected to one end of the open winding; first and second capacitors, each connected in series with respect to the positive and negative lines, with their connection points connected to the second battery side of the series line compared to the third relay; and intermediate potential switches for each phase, each provided on the intermediate potential line connecting the connection points of the first upper and first lower arms of each phase to the connection points of the first and second capacitors, respectively. The second inverter section has a second upper arm and a second lower arm for each phase, which are connected in series with respect to the positive electrode line and the negative electrode line, and whose connection points are connected to the other end of the open winding. If an open circuit abnormality occurs in at least one of the first upper arm and first lower arm of each phase, or if a short circuit abnormality occurs in at least one of the intermediate potential switches of each phase, the control device turns on the first and fourth relays, turns off the second and third relays, turns on the first and second changeover switches, turns off the first upper arm and first lower arm of each phase, turns on the intermediate potential switches of each phase, and drives the motor by switching the second inverter unit. Electric car.

3. A battery system comprising: a first battery whose first positive terminal is connected to a positive line; a second battery whose second negative terminal is connected to a negative line; a first relay provided on the positive line; a second relay provided on the negative line; a third relay provided on a series line connecting the first negative terminal of the first battery and the second positive terminal of the second battery; and a fourth relay provided on a parallel line connecting the series line on the side of the series line closer to the first battery than the third relay and the negative line further from the second battery than the second relay; A motor for traction having a three-phase open winding, A power converter comprising: a first inverter unit connected to the positive electrode line and the negative electrode line and connected to one end of the three-phase open winding; a second inverter unit connected to the positive electrode line and the negative electrode line on a side further from the battery system than the first inverter unit and connected to the other end of the three-phase open winding; and first and second changeover switches provided between the first and second inverter units of the positive electrode line and the negative electrode line. Control device and An electric vehicle equipped with, The first inverter unit includes a first upper arm and a first lower arm for each phase, each connected in series with respect to the positive and negative lines, with their connection points connected to one end of the open winding; first and second capacitors, each connected in series with respect to the positive and negative lines, with their connection points connected to the second battery side of the series line compared to the third relay; and intermediate potential switches for each phase, each provided on the intermediate potential line connecting the connection points of the first upper and first lower arms of each phase to the connection points of the first and second capacitors, respectively. The second inverter section has a second upper arm and a second lower arm for each phase, which are connected in series with respect to the positive electrode line and the negative electrode line, and whose connection points are connected to the other end of the open winding. If an open circuit abnormality occurs in at least one of the first upper arms of each phase, or if a short circuit abnormality occurs in at least one of the first lower arms of each phase, the control device turns on the first, second, and third relays, turns off the fourth relay, turns on the first and second changeover switches, turns off the first upper arms of each phase, turns on the first lower arms of each phase, turns off the intermediate potential switches of each phase, and drives the motor by switching the second inverter unit. Electric car.

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