Electric automobile

Abstract

A control device for an electric vehicle is configured so as to determine which of a first upper arm and a first lower arm of an open-circuit abnormal phase of a first inverter is an open-circuit abnormal phase on the basis of whether or not all of the three-phase first upper arm or the three-phase first lower arm can be brought into a conductive state when an open-circuit abnormal phase of an arm of any phase of the first inverter is detected, and to control the open-circuit abnormal phase of the first inverter on the basis of whether or not all of the three-phase first upper arm or the three-phase first lower arm can be brought into a conductive state. And determining which of the second upper arm and the second lower arm of the open-circuit abnormal phase of the second inverter is an open-circuit abnormal on the basis of whether or not all of the second upper arms of the three phases or the second lower arms of the three phases can be brought into a conductive state when the open-circuit abnormal of the arm of any phase of the second inverter is detected.

Description

Technical Field

[0001] This invention relates to an electrified vehicle. Background Technology

[0002] Previously, an electric vehicle was proposed, comprising: first and second energy storage devices; a motor having a three-phase open winding; a first inverter connected to a first positive terminal line and a first negative terminal line of the first energy storage device, and connected to one end of the three-phase open winding, having a three-phase first upper arm and a three-phase first lower arm; and a second inverter connected to a second positive terminal line and a second negative terminal line of the second energy storage device, and connected to the other end of the three-phase open winding, having a three-phase second upper arm and a three-phase second lower arm (for example, see Japanese Patent Application Laid-Open No. 2020-058176). Summary of the Invention

[0003] In such an electric vehicle, there is a requirement to provide a method for determining which of the upper and lower arms of a phase is faulty when an open-circuit fault is detected in the arm of any phase of the first inverter or the second inverter. The main objective of the electric vehicle of the present invention is to be able to determine which of the upper and lower arms of a phase is faulty when an open-circuit fault is detected in the arm of any phase of the first inverter or the second inverter.

[0004] The electric vehicle of the present invention includes: an energy storage device;

[0005] The motor has three-phase open windings;

[0006] The first inverter is connected to the first positive side line and the first negative side line of the energy storage device, and is connected to one end of the three-phase open winding and has a three-phase first upper arm and a three-phase first lower arm.

[0007] A second inverter, which is connected to the first positive terminal line and the first negative terminal line on the side opposite to the first inverter to the energy storage device, and is connected to the other end of the three-phase open winding, and has a three-phase second upper arm and a three-phase second lower arm; and

[0008] Control device,

[0009] The control device performs the following processing:

[0010] If an open-circuit fault is detected in any phase arm of the first inverter, the system determines which of the first upper and lower arms of the phase with the open-circuit fault is open-circuit faulted, based on whether the first upper arm of the three phases or the first lower arm of the three phases can be set to the conducting state.

[0011] If an open-circuit fault is detected in any phase arm of the second inverter, the open-circuit fault is determined by whether the second upper arm of the three phases or the second lower arm of the three phases can be set to the conducting state.

[0012] In the event of an open-circuit fault in any phase arm of the first or second inverter, the side of the upper and lower arms of the three phases that does not contain the open-circuit fault can be set to the three-phase conduction state (current flowing through the three-phase conduction state). In contrast, the side of the arm that contains the open-circuit fault cannot be set to the three-phase conduction state (current not flowing through the three-phase conduction state).

[0013] Therefore, based on this, it is possible to determine which of the upper and lower arms of the phase with the open circuit abnormality is abnormal.

[0014] In the electric vehicle of the present invention, the control device may be configured to perform the following processing:

[0015] If an overcurrent is detected by the first inverter, the phase of the first inverter with an open-circuit fault is determined based on the cumulative value of the phase current of each phase over a specified period; and

[0016] If an overcurrent is detected by the second inverter, the phase of the second inverter with an open-circuit fault is determined based on the cumulative value of the phase current of each phase of the second inverter over the specified period.

[0017] In the electric vehicle of the present invention, it may be configured to further include:

[0018] The first switch is located between the energy storage device and the first inverter on the first positive side line;

[0019] The second switch is located between the first and second inverters in the first positive side line;

[0020] The third switch is located between the energy storage device and the first inverter on the first negative side line;

[0021] The fourth switch is located between the first and second inverters in the first negative side line;

[0022] A fifth switch is disposed on a second positive terminal line that connects the first positive terminal line to the energy storage device side, which is closer to the first switch than the first switch, and to the second inverter side, which is closer to the second inverter side than the second switch; and

[0023] The sixth switch is located on the second negative side line, which is closer to the energy storage device than the third switch and closer to the second inverter than the fourth switch.

[0024] The control device is configured to perform the following processing:

[0025] If an open circuit abnormality is detected in any of the three phases of the first upper arm, the first, second, and sixth switches are set to the conducting state, or the fifth and sixth switches are set to the conducting state and the first lower arm of the three phases is set to the conducting state, and the second inverter is switched on and driven.

[0026] If an open circuit abnormality is detected in any of the three phases of the first lower arm, the third, fourth, and fifth switches are set to the conducting state, or the fifth and sixth switches are set to the conducting state and the first upper arm of the three phases is set to the conducting state, and the second inverter is switched on and driven.

[0027] If an open-circuit fault is detected in any one of the three phases of the second upper arm, the first and third switches are set to the ON state, or the first, second, and third switches are set to the ON state, or the first, third, and fifth switches are set to the ON state and the second lower arm of the three phases is set to the ON state, and the first inverter is switched on and off.

[0028] If an open circuit abnormality is detected in any of the three phases of the second lower arm, the first and third switches are set to the conducting state, or the first, third, and fourth switches are set to the conducting state, or the first, third, and sixth switches are set to the conducting state and the second upper arm of the three phases is set to the conducting state, and the first inverter is switched on and driven. Attached Figure Description

[0029] Hereinafter, with reference to the accompanying drawings, the features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described, in which the same reference numerals denote the same elements, and wherein:

[0030] Figure 1 This is a schematic structural diagram of a battery electric vehicle 10 according to an embodiment of the present invention.

[0031] Figure 2 This is a flowchart illustrating an example of an open-circuit faulty component detection routine.

[0032] Figure 3 This is an illustrative diagram illustrating an example of an open-circuit fault occurring in the first upper arm of the U phase of the first inverter in an H-drive system.

[0033] Figure 4 This is a flowchart representing an example of an avoidance driving control routine.

[0034] Figure 5 This is an explanatory diagram illustrating an example of the first avoidance driving control situation.

[0035] Figure 6 This is an explanatory diagram illustrating an example of the third avoidance driving control situation. Detailed Implementation

[0036] The embodiments for carrying out the present invention will be described with reference to the accompanying drawings. Figure 1 This is a schematic structural diagram of a pure electric vehicle 10 according to an embodiment of the present invention. As shown in the figure, the pure electric vehicle 10 of the embodiment includes a battery 12 as an energy storage device, a motor 20, first and second inverters 22 and 24, first to sixth switches SW1 to SW6, a capacitor 30, and an electronic control unit (hereinafter referred to as "ECU") 50 as a control device.

[0037] Battery 12 is configured as, for example, a lithium-ion secondary battery or a nickel-metal hydride secondary battery, and is connected to the first positive terminal line 16p and the first negative terminal line 16n. Motor 20 is configured as a three-phase AC motor, having a rotor with permanent magnets embedded in the rotor core and a stator with three-phase (U-phase, V-phase, W-phase) coils (three-phase open winding) wound on the stator core. The rotor is connected to a drive shaft that is connected to the drive wheel via a differential gear.

[0038] The first and second inverters 22 and 24 each have six transistors T11 to T16 and T21 to T26 as multiple switching elements, and six diodes D11 to D16 and D21 to D26 connected in parallel with each of the six transistors T11 to T16 and T21 to T26. Transistors T11 to T16 and T21 to T26 may be MOSFETs or IGBTs, for example. Transistors T11 to T16 and T21 to T26 are configured in pairs, with respect to the first positive side line 16p and the first negative side line 16n, in a source-drain configuration. 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 20 via U-phase, V-phase, and W-phase lines 21u, 21v, and 21w, respectively. The connection points of transistors T21 and T24, transistors T22 and T25, and transistors T23 and T26 are respectively connected to the other ends of the U-phase, V-phase, and W-phase coils of motor 20 via U-phase, V-phase, and W-phase lines 23u, 23v, and 23w. Hereinafter, transistors T11 to T13 and diodes D11 to D13 are sometimes referred to as the "first upper arm," transistors T14 to T16 and diodes D14 to D16 as the "first lower arm," transistors T21 to T23 and diodes D21 to D23 as the "second upper arm," and transistors T24 to T26 and diodes D24 to D26 as the "second lower arm." The first inverter 22 also includes an overcurrent detection circuit 22oc for detecting overcurrent in any one of the U-phase, V-phase, and W-phase lines 21u, 21v, and 21w. The second inverter 24 also has an overcurrent detection circuit 24oc that detects overcurrent in any one of the U-phase, V-phase, and W-phase lines 23u, 23v, and 23w. Furthermore, the overcurrent detection circuits 22oc and 24oc are designed to detect overcurrent on the other side only when an overcurrent is detected, based on the current decay caused by the RL component of the three-phase coils of the motor 20.

[0039] Switch SW1 is located between battery 12 and inverter 22 on the first positive side line 16p. Switch SW2 is located between inverters 22 and 24 on the first positive side line 16p. Switch SW3 is located between battery 12 and inverter 22 on the first negative side line 16n. Switch SW4 is located between inverters 22 and 24 on the first negative side line 16n. Switch SW5 is located on the second positive side line 17p, which connects to the first positive side line 16p (closer to battery 12 than switch SW1) and to the first positive side line 16p (closer to second inverter 24 than switch SW2). The sixth switch SW6 is located on the second negative side line 17n, which is closer to the battery 12 side than the third switch SW3 and closer to the second inverter 24 side than the fourth switch SW4, connecting the first negative side line 16n. The capacitor 30 is connected to the first positive side line 16p and the first negative side line 16n, which are closer to the battery 12 side than the first and third switches SW1 and SW3.

[0040] ECU 50 is equipped with a microcomputer or various drive circuits and logic ICs, including a CPU, ROM, RAM, flash memory, input / output ports, and communication ports. Signals from various sensors are input to ECU 50. For example, the voltage Vb of battery 12 from voltage sensor 12V, the current Ib of battery 12 from current sensor 12i, and the temperature Tb of battery 12 from temperature sensor 12t are input to ECU 50. The ECU 50 also receives inputs from the rotational position θm of the motor 20 rotor from rotational position sensor 20a, and the phase currents Iu, Iv, and Iw of the motor 20's U-phase, V-phase, and W-phase from current sensors 20u, 20v, and 20w (positive values ​​are from the first inverter 22 towards the motor 20). The ECU 50 also receives signals from overcurrent detection circuits 22oc and 24oc, and the voltage VH of capacitor 30 from voltage sensor 30V. The following signals are also input to ECU50: on / off signal from the power switch, shift position SP from the shift position sensor as the operating position of the shift lever, throttle opening Acc from the accelerator pedal position sensor as the amount of accelerator pedal depressed, brake pedal position BP from the brake pedal position sensor as the amount of brake pedal depressed, and vehicle speed V from the vehicle speed sensor.

[0041] Various control signals are output from ECU 50. For example, ECU 50 outputs control signals for transistors T11 to T16, T21 to T26 of inverters 22 and 24, and switches SW1 to SW6 of inverters 1 to 6. ECU 50 calculates the state of charge (SOC) of battery 12 based on the cumulative value of current Ib of battery 12. ECU 50 calculates the electrical angle θe or rotational speed Nm of motor 20 based on the rotational position θm of the rotor of motor 20. ECU 50 also calculates the waveform center deviation (deviation from the value of 0) ΔIu, ΔIv, ΔIw, which are the cumulative values ​​of the phase currents Iu, Iv, Iw of each phase of motor 20 over a specified period (e.g., the period corresponding to one cycle of electrical angle θe of motor 20).

[0042] In the battery electric vehicle 10 of the embodiment, the ECU 50 basically sets switches SW1 to SW4 (first to fourth) to the on state and switches SW5 and SW6 (fifth and sixth) to the off state. Then, the required torque Td* for driving is set according to the throttle opening Acc and the vehicle speed V. Based on the set required torque Td*, the torque command Tm* of the motor 20 is set for driving. The transistors T11 to T16 and T21 to T26 of the first and second inverters 22 and 24 are switched to drive the motor 20 with the torque command Tm*. Hereinafter, driving the motor 20 by switching the first and second inverters 22 and 24 will be referred to as "H-drive".

[0043] Next, the operation of the battery electric vehicle 10 according to the embodiment, especially the operation when any one of the transistors T11 to T16 and T21 to T26 of the first and second inverters 22 and 24 experiences an open circuit abnormality during H-drive driving, will be described. Figure 2 This is a flowchart illustrating an example of an open-circuit fault detection routine executed by ECU 50. This routine is executed when ECU 50 detects an overcurrent in one of the first and second inverters 22 and 24 based on signals from overcurrent detection circuits 22oc and 24oc. Furthermore, if an open-circuit fault occurs in any of transistors T11 to T16 and T21 to T26, an overcurrent may occur in one of the first and second inverters 22 and 24 due to motor control malfunctions, etc. And, if an overcurrent is detected in one of the first and second inverters 22 and 24, ECU 50 performs a shutdown process on the first and second inverters 22 and 24, that is, it controls the first and second inverters 22 and 24 to make all transistors T11 to T16 and T21 to T26 disconnected.

[0044] If this routine is executed, firstly, ECU50 determines which of the first and second inverters 22 and 24 (overcurrent detection circuits 22oc and 24oc) has detected an overcurrent (S100). If it is determined that an overcurrent has been detected in the first inverter 22, the waveform center deviations ΔIu, ΔIv, and ΔIw of each phase before the shutdown process of the first and second inverters 22 and 24 are used to determine the phase with an open circuit abnormality in each phase of the first inverter 22 (S110), and determines which of the phases, U, V, or W, is the open circuit abnormality (S112). Figure 3 This diagram illustrates an example of an open-circuit fault occurring in the first upper arm (transistor T11) of phase U of the first inverter 22 during H-drive operation. When all transistors T11 to T16 and T21 to T26 of the first and second inverters 22 and 24 are functioning normally, the waveform center deviations ΔIu, ΔIv, and ΔIw for each phase are approximately 0. In contrast, if an open-circuit fault occurs in the first upper arm of phase U of the first inverter 22, the phase current Iu of phase U becomes as follows: Figure 3 The waveform shown has a U-phase waveform center deviation ΔIu that is a relatively large absolute value. Therefore, for example, by comparing the absolute values ​​of the waveform center deviations ΔIu, ΔIv, and ΔIw with a threshold, the phase with the open-circuit anomaly can be identified.

[0045] When phase U is determined to be the open-circuit fault in S112, after the shutdown process of the first and second inverters 22 and 24 is executed, the conduction process of the first lower arm of the three phases is executed (S120), and it is determined whether all the first lower arms of the three phases can be set to the conducting state (S122). Here, in the conduction process of the first lower arm of the three phases, the first inverter 22 is controlled so that all transistors T11 to T13 are in the off state and all transistors T14 to T16 are in the conducting state. If the conduction process of the first lower arm of the three phases is executed while the motor 20 is rotating, the current based on the back electromotive force generated by the rotation of the motor 20 flows through each phase of the motor 20. At this time, depending on whether all the first lower arms of the three phases can be set to the conducting state, the waveforms or waveform center deviations ΔIu, ΔIv, ΔIw of the phase currents Iu, Iv, and Iw of each phase are different. The inventors have confirmed this through experiments and analysis. Therefore, these methods can be used to determine whether all three phases' lower arms can be set to the conducting state. If it is determined that all three phases' lower arms can be set to the conducting state, the upper arm of phase U (transistor T11) is determined to be open-circuit faulty (S124), and the routine ends. Conversely, if it is determined that only a portion of the three phases' lower arms can be set to the conducting state, the lower arm of phase U (transistor T14) is determined to be open-circuit faulty (S126), and the routine ends. In this way, it is possible to determine which of the upper and lower arms of phase U is open-circuit faulty.

[0046] When phase V is determined to be open-circuit faulty in S112, the shutdown process of inverters 22 and 24 is executed, followed by the turn-on process of the lower arm of the three phases (S130), and it is determined whether all lower arms of the three phases can be turned on (S132). Then, if it is determined that all lower arms of the three phases can be turned on, the upper arm of phase V (transistor T12) is determined to be open-circuit faulty (S134), and the routine ends. On the other hand, if it is determined that it is not possible to turn on a portion of the lower arms of the three phases, the lower arm of phase V (transistor T15) is determined to be open-circuit faulty (S136), and the routine ends. In this way, it is possible to determine which upper arm and lower arm of phase V is open-circuit faulty.

[0047] When phase W is determined to be open-circuit faulty in S112, the shutdown process of inverters 22 and 24 is executed, followed by the turn-on process of the first lower arm of the three phases (S140), and it is determined whether all the first lower arms of the three phases can be set to the conducting state (S142). Then, if it is determined that all the first lower arms of the three phases can be set to the conducting state, the first upper arm of phase W (transistor T13) is determined to be open-circuit faulty (S144), and the routine ends. On the other hand, if it is determined that it is not possible to set a portion of the first lower arms of the three phases to the conducting state, the first lower arm of phase W (transistor T16) is determined to be open-circuit faulty (S146), and the routine ends. In this way, it is possible to determine which of the first upper arm and the first lower arm of phase W is open-circuit faulty.

[0048] If an overcurrent is detected in the second inverter 24 in S100, similar to the process in S110, the waveform center deviations ΔIu, ΔIv, and ΔIw of each phase before the shutdown processes of the first and second inverters 22 and 24 are used to determine the phase with an open-circuit fault in each phase of the second inverter 24 (S150), and it is determined which of the three phases (U, V, or W) is the open-circuit faulty phase (S152). If the open-circuit faulty phase is determined to be the U phase in S152, after the shutdown processes of the first and second inverters 22 and 24 are executed, the conduction process of the second lower arm of the three phases is executed (S160), and it is determined whether the second lower arm of all three phases can be set to the conduction state (S162). Here, in the turn-on process of the second lower arm of the three phases, the second inverter 24 is controlled to make all transistors T21 to T23 off and all transistors T24 to T26 on. Then, if it is determined that all the second lower arms of the three phases can be turned on, the second upper arm of phase U (transistor T21) is determined to be an open circuit fault (S164), and the routine ends. On the other hand, if it is determined that it is not possible to turn on only a portion of the second lower arms of the three phases, the second lower arm of phase U (transistor T24) is determined to be an open circuit fault (S166), and the routine ends. In this way, it is possible to determine which of the second upper and second lower arms of phase U is open circuit faulty.

[0049] When phase V is determined to be open-circuit faulty in step S152, the first and second inverters 22 and 24 are shut down. Then, the second lower arm of the three phases is turned on (S170), and it is determined whether all the second lower arms of the three phases can be turned on (S172). If it is determined that all the second lower arms of the three phases can be turned on, the second upper arm of phase V (transistor T22) is determined to be open-circuit faulty (S174), and the routine ends. Conversely, if it is determined that a portion of the second lower arms of the three phases cannot be turned on, the second lower arm of phase V (transistor T25) is determined to be open-circuit faulty (S176), and the routine ends. In this way, it is possible to determine which of the second upper and lower arms of phase V is open-circuit faulty.

[0050] When phase W is determined to be open-circuit faulty in S152, the shutdown process of inverters 22 and 24 is executed, followed by the turn-on process of the second lower arm of the three phases (S180), and it is determined whether all the second lower arms of the three phases can be set to the conducting state (S182). Then, if it is determined that all the second lower arms of the three phases can be set to the conducting state, the second upper arm of phase W (transistor T23) is determined to be open-circuit faulty (S184), and the routine ends. On the other hand, if it is determined that it is not possible to set a portion of the second lower arms of the three phases to the conducting state, the second lower arm of phase W (transistor T26) is determined to be open-circuit faulty (S186), and the routine ends. In this way, it is possible to determine which of the second upper and second lower arms of phase W is open-circuit faulty.

[0051] Next, the operation when the ECU50 detects an open-circuit fault in any of the transistors T11 to T16 of the first and second inverters 22 and 24 will be explained. Figure 4 This is a flowchart illustrating an example of an avoidance driving control routine executed by ECU 50. This routine is executed when ECU 50 detects an open-circuit fault in any of the transistors T11 to T16 and T21 to T26 of the first and second inverters 22 and 24.

[0052] If this routine is executed, ECU50 determines which of the transistors T11 to T16 and T21 to T26 of the first and second inverters 22 and 24 is found to be open-circuited (S200). Then, if it is determined that an open-circuit fault has been detected in any of the first upper arm (transistors T11 to T13) of the three phases, the first avoidance driving control is initiated (S210), and this routine is terminated. Figure 5 This is an explanatory diagram illustrating an example of the first avoidance driving control scenario. As shown, in the first avoidance driving control, switches SW1, SW2, and SW6 (1st, 2nd, and 6th) are set to the ON state, switches SW3, SW4, and SW5 (3rd, 4th, and 5th) are set to the OFF state, the first upper arm of the three-phase circuit (including the transistor with the open-circuit fault) is set to the OFF state, the first lower arm of the three-phase circuit is set to the ON state, and transistors T21 to T26 of the second inverter 24 are switched. By setting switches SW1, SW2, and SW6 (1st, 2nd, and 6th) to the ON state and switches SW3, SW4, and SW5 (3rd, 4th, and 5th) to the OFF state, the voltage of battery 12 is applied only to the second inverter 24 (reference 24) of the first and second inverters 22 and 24. Figure 5 (Thick solid line). Furthermore, by setting the first upper arm of the three phases to the off state and the first lower arm of the three phases to the on state, the first inverter 22 side of the three-phase coils of the motor 20 is neutralized (see reference). Figure 5(Thick dashed line). Hereinafter, the neutral point of motor 20 will be formed by one of the first and second inverters 22 and 24, and motor 20 will be driven by the switch of the other, which is referred to as "Y drive". In the event of an open circuit failure in any of the three phases of the first upper arm, the Y drive can perform avoidance driving through the first avoidance driving control.

[0053] If an open-circuit fault is detected in any of the three phases' first lower arm (transistors T14 to T16) in S200, the second avoidance driving control (S210) is initiated, and the current routine ends. In the second avoidance driving control, switches SW3, SW4, and SW5 are set to the ON state, switches SW1, SW2, and SW6 are set to the OFF state, the first upper arm of the three phases is set to the ON state, and the first lower arm of the three phases (including the transistor with the open-circuit fault) is set to the OFF state. Transistors T21 to T26 of the second inverter 24 are switched. By setting switches SW3, SW4, and SW5 to the ON state and switches SW1, SW2, and SW6 to the OFF state, the voltage of battery 12 is applied only to the second inverter 24 of the first and second inverters 22 and 24. Furthermore, by setting the first upper arm of the three phases to the on state and setting the first lower arm of the three phases to the off state, the first inverter 22 side of the three-phase coil of the motor 20 is neutralized. In the event of an open circuit malfunction in any of the first lower arms of the three phases, the Y drive can perform avoidance driving through the second avoidance driving control.

[0054] If an open-circuit fault is detected in any of the three phases' second upper arm (transistors T21 to T23) in S200, the third avoidance driving control (S230) is initiated and the current routine is terminated. Figure 6 This is an explanatory diagram illustrating an example of the third avoidance driving control. As shown, in the third avoidance driving control, switches SW1 and SW3 (first and third phases) are set to the ON state, switches SW2, SW4, SW5, and SW6 (second and sixth phases) are set to the OFF state, the second upper arm of the three-phase circuit (including the transistor with the open-circuit fault) is set to the OFF state, the second lower arm of the three-phase circuit is set to the ON state, and transistors T11 to T16 of the first inverter 22 are switched. By setting switches SW1 and SW3 (first and third phases) to the ON state and switches SW2, SW4, SW5, and SW6 (second and sixth phases) to the OFF state, the voltage of battery 12 is applied only to the first inverter 22 (reference 24) of the first and second inverters 22. Figure 6 (Thick solid line). Furthermore, by setting the second upper arm of the three-phase circuit to the off state and the second lower arm of the three-phase circuit to the on state, the second inverter 24 side of the motor 20 is neutralized (see reference). Figure 6 (Thick dashed line). In the event of an open circuit anomaly in any of the three phases of the second upper arm, the Y-drive can perform evasive maneuvers via the third evasive maneuver control.

[0055] If an open-circuit fault is detected in any of the two lower arms (transistors T24 to T26) of the three phases in S200, the fourth avoidance driving control (S230) is initiated, and the current routine ends. In the fourth avoidance driving control, switches SW1 and SW3 are set to the ON state, switches SW2, SW4, SW5, and SW6 are set to the OFF state, the upper arm of the three phases is set to the ON state, and the lower arm of the three phases (including the transistor with the open-circuit fault) is set to the OFF state. Transistors T11 to T16 of the first inverter 22 are switched. By setting switches SW1 and SW3 to the ON state and switches SW2, SW4, SW5, and SW6 to the OFF state, the voltage of battery 12 is applied only to the first inverter 22 of the first and second inverters 22 and 24. Furthermore, by setting the second upper arm of the three phases to the on state and setting the second lower arm of the three phases to the off state, the second inverter 24 side of the motor 20 is neutralized. In the event of an open circuit malfunction in any of the second lower arms of the three phases, the Y drive can perform avoidance driving through the fourth avoidance driving control.

[0056] In the battery electric vehicle 10 described above, if an open-circuit fault is detected in any phase arm of the first inverter 22, the open-circuit fault is determined by whether all the first lower arms of the three phases can be turned on. Similarly, if an open-circuit fault is detected in any phase arm of the second inverter 24, the open-circuit fault is determined by whether all the second lower arms of the three phases can be turned on. This allows for the identification of which phase's upper or lower arm is open-circuited. In other words, the transistor with the open-circuit fault can be determined.

[0057] In the above embodiment, if an open-circuit fault is detected in any phase arm of the first inverter 22, the open-circuit fault is determined by whether the first lower arm of all three phases can be set to the conducting state. Alternatively, the open-circuit fault can also be determined by whether the first upper arm of all three phases can be set to the conducting state. The same applies when an open-circuit fault is detected in any phase arm of the second inverter 24.

[0058] In the above embodiment, in the first avoidance driving control, the first, second, and sixth switches SW1, SW2, and SW6 are set to the on state, and the third, fourth, and fifth switches SW3, SW4, and SW5 are set to the off state. Alternatively, the fifth and sixth switches SW5 and SW6 can be set to the on state, and the first, second, third, and fourth switches SW1, SW2, SW3, and SW4 can be set to the off state.

[0059] In the above embodiment, in the second avoidance driving control, the third, fourth, and fifth switches SW3, SW4, and SW5 are set to the on state, and the first, second, and sixth switches SW1, SW2, and SW6 are set to the off state. Alternatively, the fifth and sixth switches SW5 and SW6 can be set to the on state, and the first, second, third, and fourth switches SW1, SW2, SW3, and SW4 can be set to the off state.

[0060] In the above embodiments, in the third avoidance driving control, the first and third switches SW1 and SW3 are set to the on state, and the second, fourth, fifth, and sixth switches SW2, SW4, SW5, and SW6 are set to the off state. Alternatively, the first, second, and third switches SW1, SW2, and SW3 can be set to the on state, and the fourth, fifth, and sixth switches SW4, SW5, and SW6 can be set to the off state. Or, the first, third, and fifth switches SW1, SW3, and SW5 can be set to the on state, and the second, fourth, and sixth switches SW2, SW4, and SW6 can be set to the off state.

[0061] In the above embodiments, in the fourth avoidance driving control, the first and third switches SW1 and SW3 are set to the on state, and the second, fourth, fifth, and sixth switches SW2, SW4, SW5, and SW6 are set to the off state. Alternatively, the first, third, and fourth switches SW1, SW3, and SW4 can be set to the on state, and the second, fifth, and sixth switches SW2, SW5, and SW6 can be set to the off state. Or, the first, third, and sixth switches SW1, SW3, and SW6 can be set to the on state, and the second, fourth, and fifth switches SW2, SW4, and SW5 can be set to the off state.

[0062] In the above embodiment, when a short-circuit abnormality is detected in any one of the transistors T11 to T16 and T21 to T26 of the first and second inverters 22 and 24, any one of the first to fourth avoidance driving controls is executed, but only a portion may be executed, or none may be executed.

[0063] In the above embodiment, the battery electric vehicle 10 includes a second positive side line 17p and a fifth switch SW5, a second negative side line 17n and a sixth switch SW6, but is not limited thereto. For example, it may not include the second positive side line 17p and the fifth switch SW5, the second negative side line 17n and the sixth switch SW6.

[0064] In the above embodiment, the structure is set as a pure electric vehicle (battery electric vehicle) 10, but it is not limited to this. For example, it may also be set as a hybrid electric vehicle structure that has an engine in addition to the same hardware structure as the pure electric vehicle (battery electric vehicle) 10, or it may be set as a fuel cell electric vehicle structure that has a fuel cell in addition to the same hardware structure as the pure electric vehicle (battery electric vehicle) 10.

[0065] The present invention has been described above using embodiments, but the present invention is not limited to such embodiments and can of course be implemented in various ways without departing from the spirit of the present invention.

[0066] This invention can be applied to industries such as the manufacturing of electric vehicles.

Claims

1. An electric vehicle, characterized in that, have: Energy storage devices; The motor has three-phase open windings; The first inverter is connected to the first positive side line and the first negative side line of the energy storage device, and is connected to one end of the three-phase open winding and has a three-phase first upper arm and a three-phase first lower arm. A second inverter, which is connected to the first positive terminal line and the first negative terminal line on the side opposite to the first inverter to the energy storage device, and is connected to the other end of the three-phase open winding, and has a three-phase second upper arm and a three-phase second lower arm; and Control device, The control device is configured to perform the following processing: If an open circuit abnormality is detected in any phase arm of the first inverter, the first upper arm or the first lower arm of the three phases is determined to be open circuit abnormal based on whether the first upper arm or the first lower arm of the three phases can be set to the conducting state. and If an open-circuit fault is detected in any phase arm of the second inverter, the open-circuit fault is determined by whether the second upper arm of the three phases or the second lower arm of the three phases can be set to the conducting state.

2. The electric vehicle according to claim 1, characterized in that, The control device is configured to perform the following processing: If an overcurrent is detected by the first inverter, the phase of the first inverter with an open-circuit fault is determined based on the cumulative value of the phase current of each phase of the first inverter over a specified period. and If an overcurrent is detected by the second inverter, the phase of the second inverter with an open-circuit fault is determined based on the cumulative value of the phase current of each phase of the second inverter over the specified period.

3. The electric vehicle according to claim 1 or 2, characterized in that, It also has: The first switch is located between the energy storage device and the first inverter on the first positive side line; The second switch is located between the first and second inverters in the first positive side line; The third switch is located between the energy storage device and the first inverter on the first negative side line; The fourth switch is located between the first and second inverters in the first negative side line; A fifth switch is disposed on a second positive terminal line that connects the first positive terminal line to the energy storage device side, which is closer to the first switch than the first switch, and to the second inverter side, which is closer to the second inverter side than the second switch; and The sixth switch is located on the second negative side line, which is closer to the energy storage device than the third switch and closer to the second inverter than the fourth switch. The control device is configured to perform the following processing: If an open circuit abnormality is detected in any of the three phases of the first upper arm, the first, second, and sixth switches are set to the conducting state, or the fifth and sixth switches are set to the conducting state and the first lower arm of the three phases is set to the conducting state, and the second inverter is switched on and driven. If an open circuit abnormality is detected in any of the three phases of the first lower arm, the third, fourth, and fifth switches are set to the conducting state, or the fifth and sixth switches are set to the conducting state and the first upper arm of the three phases is set to the conducting state, and the second inverter is switched on and driven. If an open-circuit fault is detected in any one of the three phases of the second upper arm, the first and third switches are set to the ON state, or the first, second, and third switches are set to the ON state, or the first, third, and fifth switches are set to the ON state and the second lower arm of the three phases is set to the ON state, and the first inverter is switched on and off. If an open circuit abnormality is detected in any of the three phases of the second lower arm, the first and third switches are set to the conducting state, or the first, third, and fourth switches are set to the conducting state, or the first, third, and sixth switches are set to the conducting state and the second upper arm of the three phases is set to the conducting state, and the first inverter is switched on and driven.

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