JP2020089054A - Electric vehicle - Google Patents

Abstract

To enable an electric vehicle to travel by using an inverter to drive a motor even when a failure occurs in any of current sensors, when a disconnection failure occurs in wire connection of any of phases, or when an open failure occurs in any of switching elements.SOLUTION: When there occurs any failure of a failure in any of current sensors, a disconnection failure in wire connection of any of phases, and an open failure in any of switching elements, an estimated torque of a motor is calculated on the basis of a rotation number of the motor and an input voltage and input current of an inverter. Then, the inverter is controlled while voltage commands of a d-axis and q-axis are set by using feedback control based on a difference between a torque command and the estimated torque, or by using feedback control based on differences between current commands of the d-axis and q-axis and estimated currents of the d-axis and q-axis based on the estimated torque.SELECTED DRAWING: Figure 4

Description

The present invention relates to an electric vehicle, and more particularly to a motor and an inverter.

Conventionally, as this type of electric vehicle, there has been proposed an electric vehicle that includes a traveling motor and an inverter that drives the motor, and that shuts down the inverter when overcurrent or overvoltage occurs in the inverter (for example, , Patent Document 1). In this electric vehicle, after shutting down the inverter, an ON signal is output to all of the upper or lower switching elements in all three phases of the inverter, and if a half-wave AC is detected in either phase, half-wave is detected. It is determined that an open failure has occurred in the switching element to which the ON signal is input in the phase in which the alternating current is detected.

JP, 2017-69997, A

In such an electric vehicle, when a failure occurs in any of the current sensors of the plurality of current sensors that detect the current of each phase of the motor, or when the wiring of any phase of the wiring of each phase from the inverter to the motor is connected. If a disconnection fault occurs in the inverter, an open fault occurs in any one of the switching elements of the inverter, and the inverter is shut down, the motor cannot be driven by the inverter and traveling is restricted.

The electric vehicle of the present invention has a structure in which, when a failure occurs in any current sensor among a plurality of current sensors that detect the current of each phase of the motor, or when any one of the wirings of each phase from the inverter to the motor is connected. The main purpose of the present invention is to drive the motor by the inverter to enable traveling even when a disconnection failure occurs in the connection of the above and even when an open failure occurs in any one of the plurality of switching elements of the inverter.

The electric vehicle of the present invention employs the following means in order to achieve the above-mentioned main object.

The electric vehicle of the present invention is
A motor for traveling,
An inverter for driving the motor,
A plurality of current sensors for detecting the current of each phase of the motor,
A d-axis and q-axis current command is set based on the motor torque command, and a difference between the d-axis and q-axis current command and the d-axis and q-axis current based on the detected current of each phase. And a controller for controlling the inverter by setting voltage commands for the d-axis and the q-axis using feedback control based on
An electric vehicle comprising:
The control device is
Failure of any current sensor of the plurality of current sensors, disconnection failure of connection of any phase of connections of each phase from the inverter to the motor, any of a plurality of switching elements of the inverter When one of the open failures of the switching element occurs,
Calculate the estimated torque of the motor based on the rotation speed of the motor and the input voltage and input current of the inverter,
Feedback using feedback control based on a difference between the torque command and the estimated torque, or feedback based on a difference between the d-axis and q-axis current commands and the d-axis and q-axis estimated currents based on the estimated torque Control to set the d-axis and q-axis voltage commands to control the inverter,
That is the summary.

In the electric vehicle of the present invention, a failure of any of the current sensors among the plurality of current sensors, a disconnection failure of the connection of any phase among the connections of each phase from the inverter to the motor, a plurality of switching elements of the inverter When any one of the switching elements has an open failure, an estimated torque of the motor is calculated based on the rotation speed of the motor and the input voltage and the input current of the inverter. Then, feedback control based on the difference between the torque command and the estimated torque is used, or feedback control based on the difference between the d-axis and q-axis current commands and the estimated currents on the d-axis and the q-axis based on the estimated torque is performed. It is used to set the d-axis and q-axis voltage commands to control the inverter. By performing such control, any one of the plurality of current sensors has a failure, one of the phases of the wiring from the inverter to the motor has a disconnection failure, and the switching elements of the inverter have a plurality of switching elements. Even when an open failure occurs in any of the switching elements, the motor can be driven by the inverter to run.

It is a block diagram which shows the outline of a structure of the electric vehicle 20 as one Example of this invention. 6 is a flowchart showing an example of a control routine executed by the ECU 50. It is a flow chart which shows an example of control at the time of normal. It is a flow chart which shows an example of control at the time of abnormalities. It is explanatory drawing which shows an example of the current waveform of each phase when disconnection failure flag F2 has set the value to 1 and abnormal time control is performed, when disconnection failure generate|occur|produces in the connection of U phase. It is explanatory drawing which shows an example of the current waveform of each phase when abnormality occurs in the transistor T1 and the element open failure flag F3 becomes the value 1 and abnormal time control is performed. It is a flow chart which shows an example of control at the time of normal of a modification. It is a flow chart which shows an example of control at the time of abnormalities of a modification. It is a flow chart which shows an example of control at the time of abnormalities of a modification. It is a block diagram which shows the outline of a structure of the hybrid vehicle 120 of a modification. It is a block diagram which shows the outline of a structure of the hybrid vehicle 220 of a modification.

Next, modes for carrying out the present invention will be described using examples.

FIG. 1 is a configuration diagram showing an outline of a configuration of an electric vehicle 20 as an embodiment of the present invention. As illustrated, the electric vehicle 20 of the embodiment includes a motor 32, an inverter 34, a battery 36 as a power storage device, and an electronic control unit (hereinafter referred to as “ECU”) 50.

The motor 32 is configured as a synchronous generator motor, and includes a rotor in which a permanent magnet is embedded in a rotor core, and a stator in which a three-phase coil is wound around the stator core. The motor 32 is connected to a drive shaft 26 whose rotor is connected to drive wheels 22a and 22b through a differential gear 24.

The inverter 34 is used to drive the motor 32. The inverter 34 is connected to the battery 36 via a power line 38, and includes transistors T11 to T16 as six switching elements and six diodes D11 to T11 connected in parallel to each of the six transistors T11 to T16. And D16. Each of the transistors T11 to T16 is arranged in pairs so that each of the transistors T11 to T16 is on the source side and the sink side of the positive side line and the negative side line of the power line 38. Further, each of the three-phase coils (U-phase, V-phase, W-phase coils) of the motor 32 is connected to each of the connection points of the paired transistors of the transistors T11 to T16. Therefore, when a voltage is applied to the inverter 34, the ECU 50 adjusts the on-time ratio of the pair of transistors T11 to T16, thereby forming a rotating magnetic field in the three-phase coil and rotating the motor 32. Driven.

The battery 36 is configured as, for example, a lithium ion secondary battery or a nickel hydrogen secondary battery, and is connected to the inverter 34 via the power line 38 as described above. Capacitors 39 are attached to the positive and negative lines of the power line 38.

The ECU 50 is configured as a microprocessor centered on a CPU 52, and includes, in addition to the CPU 52, a ROM 54 that stores a processing program, a RAM 56 that temporarily stores data, an input/output port, and a communication port. Signals from various sensors are input to the ECU 50 via input ports. The signals input to the ECU 50 include, for example, a rotational position θm of the rotor of the motor 32 from a rotational position detection sensor (for example, a resolver) 32a that detects the rotational position of the rotor of the motor 32, a U-phase of the motor 32, The U-phase and V-phase currents Iu and Iv of the motor 32 from the current sensors 32u and 32v for detecting the V-phase current can be mentioned. Moreover, the voltage Vb of the battery 36 from the voltage sensor 36a attached between the terminals of the battery 36, and the current Ib of the battery 36 from the current sensor 36b attached to the output terminal of the battery 36 can also be mentioned. Further, an ignition signal from the ignition switch 60, a shift position SP from a shift position sensor 62 that detects the operation position of the shift lever 61, and an accelerator opening Acc from an accelerator pedal position sensor 64 that detects the amount of depression of the accelerator pedal 63 Acc The brake pedal position BP from the brake pedal position sensor 66 that detects the depression amount of the brake pedal 65 and the vehicle speed V from the vehicle speed sensor 68 can also be mentioned. From the ECU 50, switching control signals and the like to the transistors T11 to T16 of the inverter 34 are output via the output port. The ECU 50 calculates the electrical angle θe and the rotational speed Nm of the motor 32 based on the rotational position θm of the rotor of the motor 32 detected by the rotational position detection sensor 32a.

In the electric vehicle 20 of the embodiment thus configured, the ECU 50 sets the required torque Td* required for traveling (required for the drive shaft 26) based on the accelerator opening Acc and the vehicle speed V, and the required torque Td* is set to the torque command Tm* of the motor 32. Then, switching control of the transistors T11 to T16 of the inverter 34 is performed using the torque command Tm* of the motor 32.

Next, the operation of the thus configured electric vehicle 20 of the embodiment, particularly the control of the inverter 34 will be described. FIG. 2 is a flowchart showing an example of a control routine executed by the ECU 50. This routine is repeatedly executed.

When the control routine of FIG. 2 is executed, the ECU 50 first inputs data such as the current sensor failure flag F1, the disconnection failure flag F2, and the element open failure flag F3 (step S100). Here, the current sensor failure flag F1 is set to a value 0 by the current sensor failure flag setting routine executed by the ECU 50 when neither of the current sensors 32u and 32v has a failure, and the current sensor failure flag F1 is set to 0. The flag is set to a value of 1 when any one of the current sensors has a failure. The disconnection failure flag F2 is set to a value of 0 by the disconnection failure flag setting routine executed by the ECU 50 when there is no disconnection failure in any of the connections of each phase from the inverter 34 to the motor 32, and the connection of each phase is connected. This is a flag that is set to a value of 1 when a disconnection failure has occurred in the connection of one of the phases. The element open failure flag F3 is set to a value 0 by the element open failure flag setting routine executed by the ECU 50 when no open failure occurs in any of the transistors T11 to T16 of the inverter 34, and among the transistors T11 to T16, This flag is set to a value of 1 when any of the transistors has an open failure. It should be noted that a method of determining whether or not any one of the current sensors 32u and 32v has a failure, and a disconnection failure in any one of the phase connections from the inverter 34 to the motor 32. The method for determining whether or not the transistor has occurred and the method for determining whether or not the open failure has occurred in any one of the transistors T11 to T16 are well known, and detailed description thereof will be omitted.

While inputting data in this way, the values of the current sensor failure flag F1, the disconnection failure flag F2, and the element open failure flag F3 are checked (steps S110 to S130). Then, when all of the current sensor failure flag F1, the disconnection failure flag F2, and the element open failure flag F3 are 0, the normal control of FIG. 3 is executed (step S140), and this routine is ended. On the other hand, when the current sensor failure flag F1 has the value 1, the disconnection failure flag F2 has the value 1, and the element open failure flag F3 has the value 1, the abnormal time control of FIG. 4 is executed (step S150). This routine ends. Hereinafter, the normal control shown in FIG. 3 and the abnormal control shown in FIG. 4 will be described in this order.

In the normal control of FIG. 3, the ECU 50 first inputs data such as the torque command Tm* of the motor 32, the electrical angle θe, the phase currents Iu and Iv of the U-phase and the V-phase (step S200). Here, as the torque command Tm* of the motor 32, the value set by the above control is input. As the electrical angle θe of the motor 32, a value calculated based on the rotational position θm of the rotor of the motor 32 detected by the rotational position detection sensor 32a is input. As the phase currents Iu and Iv of the U phase and V phase, the values detected by the current sensors 32u and 32v are input.

When data is input in this manner, the U-phase and V-phase currents Iu and Iv of the motor 32 are converted into d-axis and q-axis currents Id and Iq using the electrical angle θe of the motor 32 (three-phase/two-phase conversion). At the same time (step S210), the d-axis and q-axis current commands Id* and Iq* are set based on the torque command Tm* of the motor 32 (step S220). Here, the d-axis and q-axis current commands Id* and Iq* are torque command-current by predetermining the relationship between the torque command Tm* of the motor 32 and the d-axis and q-axis current commands Id* and Iq*. The command map is stored in the ROM 54, and when the torque command Tm* of the motor 32 is given, the corresponding d-axis and q-axis current commands Id* and Iq* are derived and set.

Then, the feedforward terms Vdff and Vqff of the voltage commands Vd* and Vq* for the d-axis and the q-axis are set based on the torque command Tm* of the motor 32 (step S230). Here, the d-axis and q-axis feedforward terms Vdff and Vqff are torque command-feedforward terms with a predetermined relationship between the torque command Tm* of the motor 32 and the d-axis and q-axis feedforward terms Vdff and Vqff. The maps are stored in the ROM 54, and when the torque command Tm* of the motor 32 is given, the corresponding d-axis and q-axis feedforward terms Vdff and Vqff are derived and set.

Further, the feedback term Vdfb of the d-axis voltage command Vd* is calculated so that the difference between the d-axis current Id and the current command Id* is canceled, and the difference between the q-axis current Iq and the current command Iq* is canceled. As described above, the feedback term Vqfb of the q-axis voltage command Vq* is calculated (step S240).

Then, the sum of the d-axis and q-axis feedforward terms Vdff and Vqff and the d-axis and q-axis feedback terms Vdfb and Vqfb is set to the d-axis and q-axis voltage commands Vd* and Vq* (step S250). , Convert the d-axis and q-axis voltage commands Vd*, Vq* into U-phase, V-phase, W-phase voltage commands Vu*, Vv*, Vw* using the electrical angle θe of the motor 32 (two-phase-3 Phase conversion) (step S260). Then, using the U-phase, V-phase, W-phase voltage commands Vu*, Vv*, Vw* and the carrier wave (triangular wave voltage), PWM signals of the transistors T11 to T16 are generated and output to the transistors T11 to T16. (Step S270), this routine ends.

Next, the abnormal time control of FIG. In the abnormal time control, the ECU 50 first inputs data such as the torque command Tm* of the motor 32, the electrical angle θe, the rotation speed Nm, the voltage Vb and the current Ib of the battery 36 (step S300). The method of inputting the torque command Tm* of the motor 32 and the electrical angle θe has been described above. As the rotation speed Nm of the motor 32, a value calculated based on the rotation position θm of the rotor of the motor 32 detected by the rotation position detection sensor 32a is input. As the voltage Vb of the battery 36, the value detected by the voltage sensor 36a is input. As the current Ib of the battery 36, the value detected by the current sensor 36b is input.

When the data is thus input, the product of the voltage Vb of the battery 36 and the current Ib is calculated as the estimated power Pmes of the motor 32 (step S310), and the estimated power Pmes of the motor 32 is divided by the rotation speed Nm of the motor 32 to obtain the motor. The estimated torque Tmes of 32 is calculated (step S320). Instead of the process of step S310, a value obtained by subtracting the power of the power device (for example, an air conditioner or a DC/DC converter) connected to the power line 38 from the product of the voltage Vb of the battery 36 and the current Ib is used as the motor. It may be calculated as the estimated power Pmes of 32. In this way, the estimated power Pmes of the motor 32 can be calculated more accurately.

Subsequently, the correction torque command Tmco* of the motor 32 is calculated so that the difference between the estimated torque Tmes of the motor 32 and the torque command Tm* is canceled (step S330), and based on the calculated correction torque command Tmco* of the motor 32. To set the d-axis and q-axis feedforward terms Vdff and Vqff (step S340), and set the d-axis and q-axis feedforward terms Vdff and Vqff to the d-axis and q-axis voltage commands Vd* and Vq*. It is set (step S350). Here, the d-axis and q-axis feedforward terms Vdff and Vqff are set by applying the correction torque command Tmco* instead of the torque command Tm* of the motor 32 to the torque command-feedforward term map described above. did.

Then, similarly to the processing in steps S260 and S270 described above, the d-axis and q-axis voltage commands Vd* and Vq* are set to the U-phase, V-phase, and W-phase voltage commands Vu using the electrical angle θe of the motor 32. *, Vv*, Vw* are converted (two-phase-three-phase conversion) (step S360), and the U-phase, V-phase, and W-phase voltage commands Vu*, Vv*, Vw* and the carrier wave (triangular wave voltage) are converted. The PWM signals of the transistors T11 to T16 are generated by using the PWM signals and output to the transistors T11 to T16 (step S370), and this routine ends.

FIG. 5 is an explanatory diagram showing an example of the current waveform of each phase when a disconnection failure occurs in the U-phase connection, the disconnection failure flag F2 has a value of 1 and abnormal time control is executed, and FIG. It is explanatory drawing which shows an example of the current waveform of each phase when abnormality occurs in the transistor T1 and the element open failure flag F3 becomes the value 1 and abnormal time control is performed.

When the current sensor failure flag F1 has a value of 1, it is not possible to detect any of the U-phase and V-phase currents Iu and Iv. Therefore, the d-axis and q-axis currents Id and Iq can be calculated. Can not. Further, when the disconnection failure flag F2 has a value of 1, the current cannot flow in the phase in which the disconnection failure has occurred (U phase in FIG. 5), so the currents Id and Iq of the d-axis and the q-axis become abnormal values. .. Further, when the element open failure flag F3 has a value of 1, the current of the phase corresponding to the transistor in which the open failure has occurred (U phase corresponding to the transistor T11 in FIG. 6) becomes a half wave, so the d-axis and the q-axis The currents Id and Iq become abnormal values. In these cases, the d-axis and q-axis feedback terms Vdfb and Vqfb cannot be properly calculated, so the d-axis and q-axis voltage commands Vd* and Vq* are set using these feedback terms Vdfb and Vqfb. Is not preferable. On the other hand, the d-axis and q-axis voltage commands Vd* and Vq* are obtained by using only the d-axis and q-axis feedforward terms Vdff and Vqff without using the d-axis and q-axis feedback terms Vdfb and Vqfb. However, in this case, the deviation between the torque command Tm* for the motor 32 and the actual torque cannot be reflected in the control.

Based on these, in the embodiment, when the current sensor failure flag F1, the disconnection failure flag F2, and the element open failure flag F3 have the value 1, the estimated power Pmes of the motor 32 based on the voltage Vb of the battery 36 and the current Ib is set to the motor. The estimated torque Tmes of the motor 32 is calculated by dividing by the rotation speed Nm of the motor 32, and the correction torque command Tmco* of the motor 32 is calculated so that the difference between the estimated torque Tmes of the motor 32 and the torque command Tm* is canceled. Then, the d-axis and q-axis feedforward terms Vdff and Vqff based on the calculated correction torque command Tmco* of the motor 32 are set to the d-axis and q-axis voltage commands Vd* and Vq* to control the inverter 34. And As a result, the inverter 32 can drive the motor 32 with a certain degree of accuracy for traveling.

In the electric vehicle 20 of the embodiment described above, when the current sensor failure flag F1, the disconnection failure flag F2, and the element open failure flag F3 have the value 1, the estimated power Pmes of the motor 32 based on the voltage Vb of the battery 36 and the current Ib. Is divided by the rotation speed Nm of the motor 32 to calculate the estimated torque Tmes of the motor 32. Subsequently, the correction torque command Tmco* of the motor 32 is calculated so that the difference between the estimated torque Tmes of the motor 32 and the torque command Tm* is canceled. Then, the d-axis and q-axis feedforward terms Vdff and Vqff based on the calculated correction torque command Tmco* of the motor 32 are set to the d-axis and q-axis voltage commands Vd* and Vq* to control the inverter 34. As a result, the inverter 32 can drive the motor 32 with a certain degree of accuracy for traveling.

In the electric vehicle 20 of the embodiment, when the current sensor failure flag F1, the disconnection failure flag F2, and the element open failure flag F3 have the value 1, the voltage Vb of the battery 36 detected by the voltage sensor 36a and the current sensor 36b are detected. The product of the current Ib of the battery 36 and the estimated power Pmes of the motor 32 is calculated. However, in these cases, since the controllability of the motor 32 is lower than that in the normal control, the actual output (torque, power) of the motor 32 vibrates in the electrical Nth order (for example, 6th order), Due to this vibration, the voltage Vb of the battery 36 detected by the voltage sensor 36a and the current Ib of the battery 36 detected by the current sensor 36b may vibrate. Therefore, the voltage Vb of the battery 36 detected by the voltage sensor 36a and the current Ib of the battery 36 detected by the current sensor 36b are subjected to a low-pass filter for removing an electrical Nth-order component and an averaging process to perform the processed voltage Vbad. Alternatively, the post-processing current Ibad may be calculated, and the estimated power Pmes of the motor 32 may be calculated based on the post-processing voltage Vbad and the post-processing current Ibad.

In the electric vehicle 20 of the embodiment, the ECU 50 executes the normal time control of FIG. 3 and the abnormal time control of FIG. 4 as the processing of steps S140 and S150 of the control routine of FIG. The normal control shown in FIG. 7 and the abnormal control shown in FIG. 8 may be executed. The normal time control of FIG. 7 is the same as the normal time control of FIG. 3 except that the process of step S230b is executed instead of the process of step S210, and the abnormal time control of FIG. 8 is the process of step S340. 4 is the same as the abnormal-time control shown in FIG. 4 except that the processes of steps S340b and S342b are executed instead. Therefore, of the normal time control of FIG. 7 and the abnormal time control of FIG. 8, the same processes as the normal time control of FIG. 3 and the abnormal time control of FIG. 4 are given the same step numbers and their detailed description is omitted. To do. Hereinafter, the normal control shown in FIG. 7 and the abnormal control shown in FIG. 8 will be described in this order.

In the normal control of FIG. 7, when the d-axis and q-axis current commands Id* and Iq* are set in step S220, the d-axis and q-axis current commands Id* and Iq* are set based on the set d-axis and q-axis current commands Id* and Iq*. The axis feedforward terms Vdff and Vqff are set (step S230b). Here, the d-axis and q-axis feedforward terms Vdff and Vqff are current command-feedforward terms with a predetermined relationship between the d-axis and q-axis current commands Id* and Iq* and the feedforward terms Vdff and Vqff. It is stored in the ROM 54 as a map, and when the d-axis and q-axis current commands Id* and Iq* are given, corresponding d-axis and q-axis feedforward terms Vdff and Vqff are derived and set from this map. I decided.

In the abnormal time control of FIG. 8, when the correction torque command Tmco* of the motor 32 is set in step S330, the d-axis and q-axis current commands Id*, Iq* are set based on the set correction torque command Tmco* of the motor 32. It is set (step S340b). In this case, the d-axis and q-axis current commands Id*, Iq* are set by applying the correction torque command Tmco* instead of the torque command Tm* of the motor 32 to the torque command-current command map described above. did.

Then, similarly to the processing in step S230b of the normal time control in FIG. 7, the d-axis and q-axis feedforward terms Vdff and Vqff are set based on the d-axis and q-axis current commands Id* and Iq*. The processing from step S342b) and step S350 is executed.

In this modified example, similarly to the embodiment, even when the current sensor failure flag F1, the disconnection failure flag F2, and the element open failure flag F3 have a value of 1, the motor 32 is driven by the inverter 34 with a certain degree of accuracy to run. You can

In this modification, the ECU 50 executes the normal time control of FIG. 7 and the abnormal time control of FIG. 8 as the processing of steps S140 and S150 of the control routine of FIG. Instead, the abnormal time control of FIG. 9 may be executed. The abnormal time control of FIG. 9 is the same as the abnormal time control of FIG. 8 except that the processes of steps S400 to S420 are executed instead of the processes of steps S330 to S350. Therefore, of the abnormal-time control shown in FIG. 9, the same processes as those in the abnormal-time control shown in FIG. 8 are designated by the same step numbers and their detailed description is omitted.

In the abnormal time control of FIG. 9, when the ECU 50 calculates the estimated torque Tmes of the motor 32 in step S320, the ECU 50 obtains the estimated currents Ides and Iqes of the d-axis and the q-axis based on the calculated estimated torque Tmes of the motor 32 (step S320). S400). Here, the estimated currents Ides and Iqes of the d-axis and the q-axis are stored in the ROM 54 as an estimated torque-estimated current map by predetermining the relationship between the estimated torque Tmes of the motor 32 and the estimated currents Ides and Iqes of the d-axis and the q-axis. When the estimated currents Ides and Iqes for the d-axis and the q-axis are stored, the corresponding estimated currents Ides and Iqes for the d-axis and the q-axis are derived from this map and obtained.

Further, similar to the process of step S220 of the normal time control of FIG. 2, the d-axis and q-axis current commands Id* and Iq* are set based on the torque command Tm* of the motor 32 (step S410). Next, the d-axis voltage command Vd* is calculated so that the difference between the d-axis estimated current Ides and the current command Id* is canceled, and the difference between the q-axis current Iq and the current command Iq* is canceled. Then, the q-axis voltage command Vq* is calculated (step S420), and the processes after step S360 are executed. Even when the abnormal time control shown in FIG. 9 is executed, the inverter 32 can drive the motor 32 with a certain degree of accuracy to drive the motor 32.

In the embodiment, the configuration of the electric vehicle 20 includes a motor 32 connected to a drive shaft 26 connected to the drive wheels 22a and 22b, an inverter 34 that drives the motor 32, and a battery 36 that exchanges electric power with the inverter 34. I explained. However, as shown in FIG. 10, in addition to the motor 32, the inverter 34, and the battery 36 similar to those of the electric vehicle 20, the transmission 130 connected to the drive shaft 26 connected to the drive wheels 22a and 22b and the motor 32. The hybrid vehicle 120 may further include the engine 122 and the engine 122 connected to the motor 32 via the clutch 129. In this hybrid vehicle 120, although not shown, the low voltage battery connected to the low voltage side power line and supplying power to the ECU 50 and the like, and the high voltage side power line connecting the inverter 34 and the battery 36 are stepped down in power. It also includes a DC/DC converter that supplies the power to the low voltage side power line. In addition to the inverter 34, the ECU 50 also controls the engine 122, the clutch 129, the transmission 130, and the DC/DC converter.

In the hybrid vehicle 120, when the current sensor failure flag F1, the disconnection failure flag F2, and the element open failure flag F3 have the value 1, the same control as the abnormal time control of FIG. 4 is performed to use the power from the engine 122. The electric power can be generated by the motor 32 to charge the battery 36. Thereby, the voltage drop of the battery 36 is suppressed, the power of the high voltage side power line is reduced by the DC/DC converter, and it becomes impossible to supply the low voltage battery, and the voltage drop of the low voltage battery is suppressed. It is possible to prevent the electric power from being unable to be supplied to the ECU 50.

In the embodiment, the configuration of the electric vehicle 20 includes a motor 32 connected to a drive shaft 26 connected to the drive wheels 22a and 22b, an inverter 34 that drives the motor 32, and a battery 36 that exchanges electric power with the inverter 34. I explained. However, as shown in FIG. 11, in addition to the motor 32, the inverter 34, and the battery 36 similar to those of the electric vehicle 20, the drive shaft 226 connected to the drive wheels 22c and 22d different from the drive wheels 22a and 22b is connected. The electric vehicle 220 may further include a motor 232 and an inverter 234 that drives the motor 232 and exchanges electric power with the battery 36.

In the electric vehicle 220, with respect to the motor 32, when the current sensor failure flag F1, the disconnection failure flag F2, and the element open failure flag F3 have the value 1, the voltage sensor 36a detects the value instead of the process of step S310 of FIG. The estimated power Pmes of the motor 32 may be calculated by subtracting the power Pm2 of the motor 232 from the product of the voltage Vb of the battery 36 and the current Ib of the battery 36 detected by the current sensor 36b. The power Pm2 of the motor 232 is estimated based on, for example, the phase currents Iu2 and Iv2 of the U phase and V phase of the motor 232 detected by the current sensors attached to the U phase and V phase of the motor 232. It can be calculated by multiplying the torque Tm2 and the rotation speed Nm2 of the motor 232 calculated based on the rotation position of the rotor of the motor 232 detected by the rotation position detection sensor.

In this modification, the configuration of the hybrid vehicle 220 including the two motors 32 and 232 has been described, but the configuration of the vehicle including the two motors 32 and 232 is not limited to the configuration of the hybrid vehicle 220. For example, in addition to connecting the motor 32 to the drive shaft 26 connected to the drive wheels 22a and 22b, the engine and the generator may be connected to the drive shaft 26 via a planetary gear.

In the electric vehicle 20 of the embodiment, the inverter 34 and the battery 36 are connected to each other via the power line 38, but a boost converter may be provided between the inverter 34 and the battery 36 in the power line 38. Good. Here, the boost converter is configured as a known boost converter having two transistors, two diodes, and a reactor. In this case, when calculating the estimated torque Tmes of the motor 32, instead of using the voltage Vb and the current Ib of the battery 36, the voltage of the low voltage side power line connecting the boost converter and the battery and the reactor are used. The flowing current may be used.

In the electric vehicle 20 of the embodiment, the battery 36 is used as the power storage device, but a capacitor may be used.

Correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem will be described. In the embodiment, the motor 32 corresponds to a “motor”, the inverter 34 corresponds to an “inverter”, the current sensors 32u and 32v correspond to “a plurality of current sensors”, and the ECU 50 corresponds to a “control device”.

The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the section of means for solving the problem. This is an example for specifically explaining the mode for carrying out the invention, and does not limit the elements of the invention described in the column of means for solving the problem. That is, the interpretation of the invention described in the column of means for solving the problem should be made based on the description in that column, and the embodiment is the invention of the invention described in the column of means for solving the problem. This is just a specific example.

Although the embodiments for carrying out the present invention have been described above with reference to the embodiments, the present invention is not limited to these embodiments, and various embodiments are possible within the scope not departing from the gist of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICABILITY The present invention is applicable to the electric vehicle manufacturing industry and the like.

20 electric vehicle, 22a, 22b, 22c, 22d drive wheels, 24 differential gear, 26,226 drive shaft, 32,232 motor, 32a rotational position detection sensor, 32u, 32v current sensor, 34,234 inverter, 36 battery, 36a Voltage sensor, 36b Current sensor, 38 Power line, 39 Capacitor, 50 Electronic control unit (ECU), 52 CPU, 54 ROM, 56 RAM, 60 ignition switch, 61 shift lever, 62 shift position sensor, 63 accelerator pedal, 64 accelerator Pedal position sensor, 65 brake pedal, 66 brake pedal position sensor, 68 vehicle speed sensor, 120,220 hybrid vehicle, 129 clutch, 130 transmission, D11 to D16 diode, T11 to T16 transistor.

Claims (1)

A motor for traveling,
An inverter for driving the motor,
A plurality of current sensors for detecting the current of each phase of the motor,
A d-axis and q-axis current command is set based on the motor torque command, and a difference between the d-axis and q-axis current command and the d-axis and q-axis current based on the detected current of each phase. And a controller for controlling the inverter by setting voltage commands for the d-axis and the q-axis using feedback control based on
An electric vehicle comprising:
The control device is
Failure of any current sensor of the plurality of current sensors, disconnection failure of connection of any phase of connections of each phase from the inverter to the motor, any of a plurality of switching elements of the inverter When one of the open failures of the switching element occurs,
Calculate the estimated torque of the motor based on the rotation speed of the motor and the input voltage and input current of the inverter,
Feedback using feedback control based on a difference between the torque command and the estimated torque, or feedback based on a difference between the d-axis and q-axis current commands and the d-axis and q-axis estimated currents based on the estimated torque Control to set the d-axis and q-axis voltage commands to control the inverter,
Electric vehicle.

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