JP2008043069A - Electric vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric vehicle control unit that determines the failure of a motor and that of a control unit itself reliably, and is advantageous to the improvement of reliability in the unit. <P>SOLUTION: An inverter 10 converts electric power from DC to AC. A permanent magnet synchronous motor 12 is driven by AC power supplied from the inverter 10. A voltage sensor 36 detects a motor voltage Vu of the permanent magnet synchronous motor 12. A failure determination means 23 determines failure related to the motor 12 based on the motor voltage Vu. For example, the failure determination means calculates electric vehicle speed Vmot from the motor voltage Vu detected by a voltage sensor 36, and outputs a failure determination signal, when the difference is larger than a reference speed difference between electric vehicle speed V_MON obtained from the outside of the control unit and the calculated electric vehicle speed Vmot. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a device for driving a permanent magnet synchronous motor by an inverter without a sensor, and more particularly to a technique for determining a failure occurring inside the device.

  When the output torque of the permanent magnet synchronous motor is controlled, it is necessary to attach a rotor position sensor in order to flow current based on the motor rotor position. However, since the rotor position sensor is relatively large in volume, there are restrictions on arrangement, there is troublesome routing of the control transmission line for transmitting the sensor output to the control device, and failure factors such as disconnection There is a problem such as that there is an increase.

On the other hand, in a permanent magnet synchronous motor, the rotor position can be known indirectly by detecting the motor back electromotive voltage generated during rotation due to the permanent magnet magnetic flux. So-called sensorless vector control for performing accurate torque control has already been put into practical use.
In sensorless vector control, the motor back electromotive force is generally estimated and calculated from an inverter voltage command applied to the motor and a detected current value flowing through the motor. However, before starting the inverter operation, it is not possible to know the rotor position of the motor, and particularly when the motor rotates at high speed and the back electromotive voltage amplitude is high, the current control is unstable when the inverter is restarted. In some cases, it may become impossible to restart due to torque generation or, in the worst case, an overcurrent protection operation.

For this reason, in Patent Document 1, a voltage sensor capable of detecting the motor back electromotive voltage when the inverter is not operating is attached, and the inverter position and the rotation frequency are estimated based on the result of estimation of the rotor position and the rotation frequency based on the detected value of the voltage sensor. It describes how to restart smoothly by restarting.
JP 2005-65410 A

  In Patent Document 1, no failure of the voltage sensor is assumed. If the voltage sensor fails, it becomes difficult to restart the inverter smoothly. In addition, in a conventional electric vehicle control device that controls an electric motor used in a train (hereinafter referred to as an electric vehicle), it is difficult to reliably determine a failure of the motor and a failure of the control device itself.

  Accordingly, it is an object of the present invention to provide an electric vehicle control device that is advantageous for reliably determining a failure of an electric motor and a failure of a control device itself and improving the reliability of the device.

  According to the present invention, in an apparatus for driving and controlling a permanent magnet synchronous motor, failure determination relating to the motor is performed based on information obtained from a voltage sensor that detects a terminal voltage of the motor.

  That is, the electric vehicle control device according to the present invention detects an inverter that converts electric power from direct current to alternating current, a permanent magnet synchronous motor driven by the alternating current power supplied from the inverter, and an electric motor voltage of the permanent magnet synchronous motor. A voltage sensor and failure determination means for determining failure of the motor based on the motor voltage are provided.

  It is possible to provide an electric vehicle control device that is advantageous to reliably determine the failure of the motor and the control device itself, and to improve the reliability of the device, and thus protect early before failure such as motor overtemperature occurs Can be stopped.

  Embodiments of the present invention will be described below with reference to the drawings.

[First embodiment]
The configuration of the first embodiment of the electric vehicle control apparatus 100 according to the present invention will be described with reference to the control block diagram of FIG. 1A.

  In FIG. 1A, the dotted line part 20 shows the whole control block. In the control block 20, 21 is a torque pattern generation unit, 23 is a failure determination means, 24 is an AND logic gate, 26 is a vector control unit, 28 is a gate start / stop control unit, 29 is a PWM gate pulse generation gate logic unit, 37 Is a motor speed calculator. Further, 9 is a filter capacitor, 10 is an inverter, 30 is a current sensor, 11 is an open contactor, 36 is a voltage sensor, and 12 is a permanent magnet synchronous motor. Next, the operation of this embodiment will be described.

(Function)
The torque pattern generation unit 21 outputs a torque command TrqRef with the operation command, the variable load command, and the brake force command as inputs. The driving command is a high or low signal, a low signal when the control lever is in the neutral position, and a high signal when the control lever is in another position. The response load command is a value that increases as the total weight of the passenger increases, and is a value calculated by a sensor outside the electric vehicle control device.

  The vector control unit 26 receives the torque command TrqRef, the motor currents Iu and Iw detected by the current sensor 30, and the filter capacitor voltage EFC, and outputs the three-phase voltage commands VuRef, VvRef, and VwRef of the inverter 10. The PWM gate pulse generation / gate logic unit 29 receives the three-phase voltage commands VuRef, VvRef, VwRef output from the vector control unit 26 and the gate start / stop signal GST output from the gate start / stop control unit 28 as inputs. When GST = “H (high level signal)” depending on the presence or absence of the gate start / stop signal GST, the three-phase voltage command is modulated by pulse width modulation, and the three-phase gate signals VuINV and VvINV are supplied to the inverter 10. , VwINV is output. When GST = “L (low level signal)”, the three-phase gate signals VuINV, VvINV, and VwINV are not output as a gate stop, and the inverter 10 is turned off.

  The inverter 10 converts the input DC power into variable voltage / variable frequency three-phase AC voltages Vu, Vv, Vw that are pulse-width controlled based on the three-phase voltage commands VuRef, VvRef, VwRef. This AC voltage is applied to the stator winding of the permanent magnet synchronous motor 12 through an open contactor 11 which is normally closed to generate a rotating magnetic field.

  The motor speed calculator 37 receives the UV voltage signal Vuv from the voltage sensor 36 connected to the opening contactor 11 and the permanent magnet synchronous motor 12 and outputs the motor speed Vmot. The motor speed calculation unit 37 detects zero-cross timings t1, t2, t3,... Of the UV voltage signal Vuv from the voltage sensor 36 as shown in FIG. 1B, and obtains a half cycle T / 2 of the UV voltage signal Vuv. From the half cycle, the frequency ωmot of the signal Vuv is calculated as the motor rotation frequency as follows.

ωmot = 1 / T
The motor speed calculation unit 37 obtains the motor speed Vmot from the frequency ωmot as in the following equation.

Vmot = ωmot × α
Here, α is a constant value determined from the wheel diameter, the gear ratio of the drive system, and the like.

  The failure determination means 23 is a motor speed V_MON transmitted from a device outside the electric vehicle control device such as a monitor device, an ATC device, an ATO device (not shown), etc., and an output of the motor speed calculation unit. A failure is determined from the speed Vmot. The vehicle speed V_MON indicates the actual vehicle speed and is, for example, a speed displayed on a speedometer in the cab.

The failure determination means 23 compares the vehicle speed V_MON with the motor speed Vmot,
If | V_MON−Vmot |> reference speed difference, it is determined that there is a failure and “L” is output to the AND logic gate 24.

If | V_MON−Vmot | ≦ reference speed difference, it is determined as normal and “H” is output to the AND logic gate 24.

  The operation command signal is input to the AND logic gate 24 as, for example, “H” when there is an operation command and “L” when there is no operation command. The AND logic gate 24 inputs the operation command signal and the determination output of the failure determination means, and only when the operation command is present (“H”) and the output of the failure determination means is normal (“H”), for example, “H”. Is output to the gate start / stop control unit 28, and even if there is an operation command (“H”), if the output of the failure determination means is a failure (“L”), “L” is output to the gate start / stop control unit 28. To do.

  The gate start / stop control unit 28 is supplied with other warning signals such as an output signal of the AND logic gate 24 and a motor overcurrent detection signal. The gate start / stop control unit 28 generates a PWM gate pulse by generating a gate start / stop signal GST = “H” when the output signal of the AND logic gate 24 is “H” and other warning signals are “H” (normal). Output to the gate logic unit 29. The gate start / stop control unit 28 outputs GST = “L” to the PWM gate pulse generation / gate logic unit 29 when the output signal of the AND logic gate 24 or other warning signal is “L”.

  In this way, even if there is a driving command, if the difference between the vehicle speed V_MON and the motor speed Vmot is greater than the reference speed difference, it is determined that there is a failure, and the PWM gate pulse generation / gate logic unit 29 determines the three-phase gate signal VuINV. , VvINV and VwINV are stopped, and the inverter 10 is turned off.

  The motor speed calculation unit 37 obtains the motor speed Vmot calculated by the motor voltage Vuv (voltage between UVs) obtained from the voltage sensor 36. As the motor voltage obtained by the voltage sensor 36, Vvw (between VW) Voltage) or Vwu (voltage between WUs) may be used.

  The reference speed difference may be a value that increases as the vehicle speed V_MON increases. 1C adopts a value that increases as the vehicle speed V_MON increases as the reference speed difference as described above, and further implements the failure determination means 23 that determines a failure when the state determined to be a failure continues for a predetermined time. It is a block diagram which shows the structure of an example. The subtractor 101 calculates a difference Vd between the vehicle speed V_MON and the motor speed Vmot. The absolute value circuit 102 calculates a difference absolute value Vad from the difference Vd.

Vad = | V_MON−Vmot |
The reference speed difference generation unit 104 outputs a reference speed difference ΔVref that changes according to the vehicle speed V_MON. FIG. 1D is a graph showing the relationship between the vehicle speed V_MON and the reference speed difference ΔVref. The reference speed difference ΔVref is, for example, a value of 5% of the vehicle speed V_MON.

  The comparator 103 compares the difference absolute value Vad with the reference speed difference ΔVref and outputs a comparison result Vcd. When the absolute difference value Vad is larger than the reference speed difference ΔVref (Vad> ΔVref), the comparator 103 outputs, for example, “L” as the comparison result Vcd. The comparator 103 outputs “H” as the comparison result Vcd when the absolute difference value Vad is equal to or less than the reference speed difference ΔVref (Vad ≦ ΔVref).

  The delay circuit 105 determines that a failure occurs when “L” of the comparison result Vcd continues for a predetermined time, and outputs, for example, “L” as the determination result. In other cases, that is, when the comparison result Vcd is “H”, or when “L” shorter than the predetermined time is input as the comparison result Vcd, the delay circuit 105 determines that it is normal and outputs “H”. . The subsequent operations are the same as in the above embodiment.

(effect)
In the present embodiment, the electric vehicle speed obtained from the outside of the control device is compared with the motor speed Vmot calculated from the motor voltage, and when the difference becomes excessive, a failure determination is output, so the failure of the voltage sensor 30 Can be reliably determined, and protection can be stopped early. That is, the reliability of the apparatus can be increased. In addition, by attaching a voltage sensor between the contactor for opening and the permanent magnet synchronous motor, even when the contactor for opening is opened due to failure / protection operation, the electric vehicle speed obtained from the outside of the control device The motor speed calculated from the motor voltage is always compared, and if the difference becomes excessive, a failure of the voltage sensor can be detected, so that an advantage of improved reliability can be obtained.

  Further, in the present embodiment, when the electric vehicle speed obtained from the outside of the control device is the correct electric vehicle speed (reference electric vehicle speed), and the difference between the motor speed calculated from the motor voltage is excessive, When the voltage sensor has failed, but the motor speed calculated from the motor voltage is the correct electric vehicle speed (reference electric vehicle speed), and the difference from the electric vehicle speed obtained from outside the controller is excessive. A failure may be determined as an abnormality in the electric vehicle speed outside the control device.

[Second Embodiment]
The configuration of the second embodiment of the electric vehicle control apparatus 100 according to the present invention will be described with reference to the control block diagram of FIG.

  The same elements as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. Only different parts will be described here. That is, as shown in FIG. 2, the control block of the present embodiment adds an electric motor frequency calculation unit 38 and an estimated frequency calculation unit 39 in place of the electric motor speed calculation unit 37 and the transmission line 42 in FIG. The motor frequency ωmot that is the output of the frequency calculation unit 38 and the estimated frequency ωest that is the output of the estimated frequency calculation unit 39 are input to the failure determination means 23. Next, the operation of this embodiment will be described.

(Function)
The motor frequency calculation unit 38 receives the UV voltage signal Vuv from the voltage sensor 36 connected to the opening contactor 11 and the permanent magnet synchronous motor 12 and outputs the motor frequency ωmot. The method for generating the motor frequency ωmot is as described with reference to FIG. 1B. The estimated frequency calculation unit 39 receives the output signals VuRef, VvRef, VwRef of the vector control unit 26 and the output signals Iu, Iw of the current sensor 30, and outputs the estimated motor frequency ωest. The estimated frequency calculation unit 39 estimates the rotor position without using a sensor for detecting the rotor position of the electric motor, and calculates the rotation frequency from the estimated rotor position. This is called “sensorless control”. Major examples of sensorless control that have been known so far include an induced voltage utilization method and a high-frequency voltage superposition method. The former is a method for estimating the rotor position by utilizing the induced voltage induced by the rotation of the synchronous motor being observed in the q-axis direction of the control rotation axis of the synchronous motor, and the latter is for controlling the synchronous motor. In this method, a high frequency component is actively superimposed on a voltage command or a current command to detect the response of the corresponding frequency, and the rotor position is estimated by estimating the impedance of the synchronous motor or calculating the evaluation function. is there. Since the present invention does not describe a sensorless control method for a permanent magnet synchronous motor, a detailed description thereof will be omitted.

The failure determination means 23 receives the output ωmot of the motor frequency calculator and the output signal ωest of the estimated frequency calculator 39, compares the motor frequency ωmot with the estimated frequency ωest,
If | ωmot−ωest |> reference frequency difference, it is determined as a failure and “L” is output to the AND logic gate 24.

If | ωmot−ωest | ≦ reference frequency difference, it is determined as normal and “H” is output to the AND logic gate 24.

  As the operation command signal, for example, “H” is output to the AND logic gate 24 when there is an operation command, and “L” is output when there is no operation command. The AND logic gate 24 receives the operation command signal and the output signal of the failure determination means as inputs, and is “H” only when there is an operation command (“H”) and the output signal of the failure determination means is normal (“H”). Is output to the gate start / stop control unit 28, and even if there is an operation command (“H”), if the output of the failure determination means is a failure (“L”), “L” is output to the gate start / stop control unit 28. To do.

  The gate start / stop control unit 28 generates a PWM gate pulse by generating a gate start / stop signal GST = “H” when the output signal of the AND logic gate 24 is “H” and other warning signals are “H” (normal). Output to the gate logic unit 29. The gate start / stop control unit 28 outputs GST = “L” to the PWM gate pulse generation / gate logic unit 29 when the output signal of the AND logic gate 24 or other warning signal is “L”.

Thus, even if there is an operation command, if the difference between the motor frequency ωmot and the estimated frequency ωest is larger than the reference frequency difference, it is determined that there is a failure, and the PWM gate pulse generation / gate logic unit 29 determines that the three-phase gate signal VuINV, The output of VvINV and VwINV is stopped, and the inverter 10 is turned off.
The motor frequency calculation unit 38 obtains the motor frequency ωmot calculated by the motor voltage Vuv (voltage between UVs) obtained from the voltage sensor 36. As the motor voltage obtained by the voltage sensor 36, Vvw (between VW) Voltage) or Vwu (voltage between WUs) may be used.

(effect)
In this embodiment, the motor frequency calculated from the motor voltage is compared with the estimated motor frequency calculated by the estimated frequency calculation unit, and if the difference is excessive, a failure determination is output, so an abnormality in the estimated frequency calculation is determined. It is possible to stop protection early. That is, the reliability of the apparatus can be increased. Further, since an estimated frequency abnormality can be detected without using a speed sensor or a rotor position sensor, advantages such as reduction in the number of parts and improvement in reliability can be obtained.

  In this embodiment, when the motor frequency calculated from the motor voltage is set to the correct frequency (reference frequency) and the difference from the motor estimated frequency calculated by the estimated frequency calculation unit is excessive, the estimated frequency calculation is abnormal. However, if the estimated motor frequency calculated by the estimated frequency calculator is the correct frequency (reference frequency) and the difference from the motor frequency calculated from the motor voltage is excessive, the voltage sensor may be faulty. You may make it determine.

[Third embodiment]
A third embodiment of the electric vehicle control apparatus 100 according to the present invention will be described with reference to the control block diagram of FIG. 3A.

  The same elements as those in FIG. 2A are denoted by the same reference numerals and description thereof is omitted, and only different parts are described here. That is, as shown in FIG. 3A, the control block of this embodiment is configured to input the vehicle speed V_MON from the outside via the transmission line 42 to the failure determination means 23 of FIG. 2A.

  FIG. 3B is a block diagram illustrating a configuration of the failure determination unit 23 according to the present embodiment. 201 is a vehicle speed / frequency converter, 202 is a reference frequency difference generator, 203 and 209 are subtractors, 204 and 210 are absolute value circuits, 205 and 211 are comparators, 206 and 212 are delay circuits, and 207 and 213 are inverters 208, 214 are set / reset flip-flops, and 215 is an AND logic gate. Next, the operation of this embodiment will be described.

(Function)
When the failure determination means 23 according to the present embodiment detects a failure by monitoring the motor frequency ωmot and the estimated frequency ωest, whether the failure has occurred on the motor frequency ωmot side (voltage sensor side circuit) or the estimated frequency ωest Is determined based on the vehicle speed V_MON.

  In FIG. 3B, the vehicle speed / frequency conversion unit 201 converts the vehicle speed V_MON into a frequency ω_MON corresponding to the vehicle speed.

ω_MON = V_MON / α
Here, α is a constant value determined from the wheel diameter, the gear ratio of the drive system and the like as described above.

  The reference frequency difference generation unit 207 generates a reference frequency difference Δωef that increases as the frequency ω_MON increases as shown in FIG. 3C. The subtractor 203 calculates a difference ωd1 between the motor frequency ωmot and the frequency ω_MON. The absolute value circuit 204 obtains a difference absolute value aωd1 from the difference ωd1.

aωd1 = | ω_MON−ωmot |
The comparator 205 compares the difference absolute value aωd1 with the reference speed difference Δωref and outputs a comparison result cω. When the difference absolute value aωd1 is larger than the reference speed difference Δωref (aωd1> Δωref), the comparator 103 outputs, for example, “L” as the comparison result cω. The comparator 205 outputs “H” as the comparison result Vcd when the absolute difference value aωd1 is equal to or smaller than the reference speed difference Δωref (aωd1 ≦ Δωref).

  The delay circuit 206 determines that a failure occurs when the comparison result cω is “L” for a predetermined time, and outputs, for example, “L” as the determination result signal md. In other cases, that is, when the comparison result cω is “H”, or when “L” shorter than the predetermined time is input as the comparison result cω, the delay circuit 206 determines that it is normal and outputs “H”. .

  The subtractor 209 calculates a difference ωd2 between the estimated frequency ωest and the frequency ω_MON. Since the operations of the absolute value circuit 210, the comparator 211, and the delay circuit 212 are the same as those of the absolute value circuit 204, the comparator 205, and the delay circuit 206, detailed description thereof is omitted.

  “L” of the determination result signal md 1 of the delay circuit 206 is input to the set terminal of the set / reset flip-flop 208 via the inverter 207 and sets the flip-flop 208. “L” of the determination result signal md2 of the delay circuit 212 is input to the set terminal of the set-reset flip-flop 214 via the inverter 213, and the flip-flop 214 is set. As a result, the set / reset flip-flops 208 and 214 output a signal indicating the failure location. The set state of the set / reset flip-flops 208 and 214 is reset by a reset signal input from the outside of the control device 20.

  The AND logic gate 215 performs an AND logic operation on the determination result signals md1 and md2 of the delay circuits 206 and 212, and outputs a final failure determination signal. That is, the AND logic gate 215 outputs “L” (failure) when at least one of the delay circuits 206 and 212 outputs “L” (failure). Subsequent operations are the same as in the second embodiment.

(effect)
As described above, in this embodiment, the motor frequency ωmot and the estimated frequency ωest are monitored based on the highly reliable vehicle speed V_MON. Therefore, when an abnormality occurs in frequency information, it is possible to reliably detect which abnormality has occurred, and the detection result is output as a failure location signal from the Q output terminals of the set-reset flip-flops 208 and 214. The That is, when a failure is detected, whether the failure has occurred on the motor frequency ωmot side (voltage sensor side circuit) or the estimated frequency ωest side (current sensor side circuit) can be easily determined by the failure location signal. Judgment can be made.

[Fourth embodiment]
The configuration of the fourth embodiment of the electric vehicle control apparatus 100 according to the present invention will be described with reference to the control block diagram of FIG. 4A.

  The same elements as those in FIG. 1A are denoted by the same reference numerals, and the description thereof is omitted. Only different parts will be described here. In other words, as shown in FIG. 4A, the control block of the present embodiment includes an electric motor frequency calculation unit 38 and a no-load induced voltage characteristic calculation unit 40 instead of the electric motor speed calculation unit 37 and the transmission line 42 in FIG. 1A. Then, the motor frequency ωmot that is the output of the motor frequency calculation unit 38 is input to the no-load induced voltage characteristic calculation unit 40, the no-load induced voltage Vnoload that is the output of the no-load induced voltage characteristic calculation unit 40, and the output of the voltage sensor The motor voltage Vuv and the gate start / stop signal GST which is the output of the gate start / stop control unit are input to the failure determination means 23. Next, the operation of this embodiment will be described.

(Function)
The motor frequency calculation unit 38 receives the output Vuv of the voltage sensor 36 connected to the opening contactor 11 and the permanent magnet synchronous motor 12 and outputs the motor frequency ωmot. The no-load induced voltage characteristic calculation unit 40 receives the output ωmot of the motor frequency calculation unit 38 and calculates a no-load induced voltage (running value) at the motor rated temperature with respect to the motor frequency. The no-load induced voltage characteristic with respect to the motor frequency is a voltage generated by the electromotive force of the permanent magnet when the inverter is off, that is, when the motor is free running, and increases with the motor frequency as shown in FIG. 4B. However, the magnetic flux density of the permanent magnet decreases as the temperature of the motor increases, and as a result, the induced voltage of the motor also decreases.

The failure determination means 23 obtains an execution value of the motor voltage Vuv that is the output of the voltage sensor 36, the execution value, the motor no-load induced voltage Vnoload that is the output of the no-load induced voltage characteristic calculation unit, and the gate start / stop. A gate start / stop signal GST which is an output of the control unit 28 is input. The failure determination means 23 compares the motor no-load induced voltage Vnoload and the motor voltage Vuv when the gate start / stop signal GST = “L” (gate stop), that is, when the inverter 10 is off.
If | Vnoload−Vuv |> reference voltage difference, it is determined that there is a failure and “L” is output to the AND logic gate 24.

If | Vnoload−Vuv | ≦ reference voltage difference, it is determined as normal and “H” is output to the AND logic gate 24.

  The operation command signal is input to the AND logic gate 24 as “H” when there is an operation command and “L” when there is no operation command.

  The AND logic gate 24 receives the operation command and the output of the failure determination means 23 and gates “H” only when the operation command is present (“H”) and the output of the failure determination means is normal (“H”). If the output of the failure determination means is a failure (“L”) even if there is an operation command (“H”), “L” is output to the gate start / stop control unit 28.

  The gate start / stop control unit 28 generates a PWM gate pulse by generating a gate start / stop signal GST = “H” when the output signal of the AND logic gate 24 is “H” and other warning signals are “H” (normal). Output to the gate logic unit 29. The gate start / stop control unit 28 outputs GST = “L” to the PWM gate pulse generation / gate logic unit 29 when the output signal of the AND logic gate 24 or other warning signal is “L”.

  As described above, the no-load induced voltage Vnoad and the motor voltage Vuv are compared based on the output of the failure determination unit 23, and if it is larger than the reference voltage difference, it is determined that a failure has occurred. If it is determined that there is a failure, the three-phase gate signals VuINV, VvINV, and VwINV are not output as a gate stop even if the operation command is changed, and the inverter 10 remains off.

  The reference voltage difference may be a value that increases as the vehicle speed V_MON increases as in the first embodiment, or a value that increases as the motor frequency ωmot increases. In addition, the motor frequency calculation unit 38 obtains the motor frequency ωmot calculated by the motor voltage Vuv (voltage between UVs) obtained from the voltage sensor 36. As the motor voltage obtained by the voltage sensor 36, Vvw (between VW) Voltage) or Vwu (voltage between WUs) may be used. Similarly, Vvw (voltage between VW) or Vwu (voltage between WU) may be used for the motor voltage input to the failure determination means 23.

(effect)
In this embodiment, the motor no-load induced voltage is compared with the motor voltage obtained from the voltage sensor while the gate is turned off, that is, the inverter is turned off. When the motor voltage Vuv obtained from the voltage sensor is smaller than the no-load induced voltage Vnoad at the motor rated temperature,
Vnoload (= ωΦ)> Vuv (= ωΦ ′)
Therefore, Φ> Φ ′.

Where ω is the motor frequency,
Φ: motor magnetic flux at the motor rated temperature,
Φ ′: Electric motor magnetic flux when the motor is overheated. That is, when the electric motor is overheated, the electric motor magnetic flux is reduced as compared with the rated temperature. Therefore, it is possible to reliably determine the motor overtemperature by detecting Vnoload and Vuv, and the protection can be stopped early. That is, the reliability of the apparatus can be increased. Further, since a temperature sensor for detecting the motor overtemperature is unnecessary, there are also advantages such as reduction in the number of parts and improvement in reliability. In addition, by mounting the voltage sensor between the contactor for opening and the permanent magnet synchronous motor, even when the contactor for opening was opened due to failure / protection operation, it was obtained from the no-load induced voltage of the motor and the voltage sensor. When the motor voltage is constantly compared and the difference becomes excessive, the motor overtemperature can be detected, and thus the advantage of improved reliability can be obtained.

[Fifth embodiment]
The configuration of the fifth embodiment of the electric vehicle control apparatus 100 according to the present invention will be described with reference to the control block diagram of FIG.

  The same elements as those in FIG. 1A are denoted by the same reference numerals, and the description thereof is omitted. Only different parts will be described here. That is, as shown in FIG. 5, the control block of the present embodiment is provided with an opening contactor operation determining means 43 in addition to the embodiment of FIG. 1A, and is an output of the opening contactor operation determining means 44. The closing / opening signal MKoff is input to the opening contactor 11. Next, the operation of this embodiment will be described.

(Function)
The operation command signal is input to the opening contactor operation determination means 43 as “H” when there is an operation command and “L” when there is no operation command. The failure determination means 23 outputs “H” when there is no failure (normal) and “L” when there is a failure to the contactor operation determination means 43 for opening. In FIG. 5, the failure determination condition of the failure determination means is shown using the first embodiment, but instead of this condition, any of the second to fourth examples and the eighth example described later is used. The failure determination condition shown in FIG.

  When there is an operation command and there is no failure (normal), the opening contactor operation determining means 43 outputs the closing / opening signal MKoff = “CLOSE” and turns on the opening contactor 11. Once the opening contactor 11 is turned on by the operation command, the opening contactor 11 is kept turned on even when there is no operation command. That is, even if the presence / absence of the operation command is repeated, if there is no failure (normal), a closing / opening signal MKoff = “CLOSE” is output and the opening contactor 11 is kept on. The contactor 11 for opening is opened only when the output of the failure determination means 23 is “L” (with failure). When there is a failure, the contactor operation determining means 43 for opening outputs a closing / opening signal MKoff = “OPEN” to open the contactor 11 for opening. A circuit for realizing the logic of the opening contactor operation determination means 43 is shown in FIG. 5B.

  In the AND logic gate 24 of FIG. 5A, only when the operation command and the output of the failure determination means are input and there is an operation command (“H”) and the output of the failure determination means is normal (“H”), “H” Is output to the gate start / stop control unit 28, and even if there is an operation command (“H”), if the output of the failure determination means is a failure (“L”), “L” is output to the gate start / stop control unit 28. To do. When the output of the AND logic gate 24 is “L”, the gate start / stop control unit 28 outputs GST = “L” to the PWM gate pulse generation / gate logic unit 29 and turns off the inverter 10.

  As described above, when the failure determining means 23 determines that a failure has occurred, the gate is stopped, the inverter is turned off, and the opening contactor 11 is opened.

(effect)
In this embodiment, the inverter and the electric motor are disconnected by turning off the inverter and opening the contactor for opening. Therefore, when the motor is rotating at high speed, the inverter can be protected from the induced voltage generated by the motor, so that the reliability of the apparatus can be increased.

[Sixth embodiment]
The configuration of the sixth embodiment of the electric vehicle control apparatus 100 according to the present invention will be described with reference to the control block diagram of FIG. 6A.

  The same elements as those in FIG. 1A are denoted by the same reference numerals, and the description thereof is omitted. Only different parts will be described here. That is, as shown in FIG. 6A, the control block of the present embodiment adds a circuit breaker operation determination means 44 in addition to FIG. 1, and opens and closes the circuit breaker that is the output of the circuit breaker operation determination means 44. The signal LBoff is input to the circuit breaker 4. Note that the DC power collected through the pantograph 1 is input to the inverter 10 through the current interrupter 4 and the smoothing reactor 6 that turn on and off the current. Next, the operation of this embodiment will be described.

(Function)
The operation command signal is input to the circuit breaker operation determination means 44 as “H” when there is an operation command and “L” when there is no operation command. The failure determination means 23 outputs “H” to the circuit breaker operation determination means 44 when there is no failure (normal) and “L” when there is a failure. In FIG. 6A, the failure determination condition of the failure determination means is shown using the first embodiment, but instead of this condition, second to fourth embodiments of the invention and a seventh embodiment described later. The failure determination condition shown in any of the above may be used.

  When there is an operation command and there is no failure (normal), the circuit breaker operation determining means 44 outputs the circuit breaker closing / opening signal LBoff = “CLOSE” and switches on the circuit breaker 4. Once the circuit breaker 4 is turned on by the operation command, the circuit breaker 4 may be turned on even when there is no operation command, or it is turned on when there is an operation command, and opened when there is no operation command. It is also good. When the output of the failure determination means 23 is “L” (there is a failure), the circuit breaker closing / opening signal LBoff = “OPEN” is output, and the circuit breaker 4 is opened. A configuration for realizing this logic is shown in FIG. 6B.

  In the AND logic gate 24 of FIG. 6A, only when the operation command and the output of the failure determination means are input and there is an operation command (“H”) and the output of the failure determination means is normal (“H”), “H” Is output to the gate start / stop control unit 28, and even if there is an operation command (“H”), if the output of the failure determination means is a failure (“L”), “L” is output to the gate start / stop control unit 28. To do.

  The gate start / stop control unit 28 outputs GST = “L” to the PWM gate pulse generation / gate logic unit 29 when the output signal of the AND logic gate 24 or other warning signal is “L”, and the inverter 10 is turned on. Turn off. As described above, when the failure determination unit 23 determines that a failure has occurred, the gate is stopped, the inverter is turned off, and the circuit breaker 4 is opened.

(effect)
In this embodiment, when a failure is detected, the inverter side including the filter capacitor and the overhead line side are disconnected by turning off the inverter and opening the circuit breaker. Therefore, unnecessary power input / output to / from the overhead line side can be avoided and the inverter can be protected, so that the reliability of the apparatus can be increased.

[Seventh embodiment]
The configuration of the second embodiment of the electric vehicle control apparatus 100 according to the present invention will be described with reference to the control block diagram of FIG.

  The same elements as those in FIG. 5A are denoted by the same reference numerals and description thereof is omitted, and only different parts are described here. That is, as shown in FIG. 7, the control block of the present embodiment adds a circuit breaker operation determination unit 44 in addition to the configuration of FIG. 5A, and turns on a circuit breaker that is the output of the circuit breaker operation determination unit 44. The open circuit signal LBoff is input to the circuit breaker 4 (note that the DC power collected via the pantograph 1 is passed through the circuit breaker 4 for turning on and off the current and the smoothing reactor 6 to the inverter 10. Entered). Next, the operation of this embodiment will be described.

(Function)
The operation command signal is input to the circuit breaker operation determination means 44 and the open contactor operation determination means 43 as “H” when there is an operation command and “L” when there is no operation command. The failure determination means 23 outputs “H” when there is no failure (normal) and “L” when there is a failure to the contactor operation determination means 43 for open circuit and the circuit breaker operation determination means 44. In FIG. 7, the failure determination condition of the failure determination means is shown by using the first embodiment, but instead of this condition, the second to fourth embodiments of the invention and the eighth embodiment described later. The failure determination condition shown in any of the examples may be used.

  When there is an operation command and there is no failure (normal), the opening contactor operation determining means 43 outputs the closing / opening signal MKoff = “CLOSE” and turns on the opening contactor 11. Once the opening contactor 11 is turned on by the operation command, the opening contactor 11 is kept turned on even when there is no operation command. That is, even if the presence / absence of the operation command is repeated, if there is no failure (normal), a closing / opening signal MKoff = “CLOSE” is output and the opening contactor 11 is kept on. The contactor 11 for opening is opened only when the output of the failure determination means 23 is “L” (with failure). When there is a failure, the contactor operation determining means 43 for opening outputs a closing / opening signal MKoff = “OPEN” to open the contactor 11 for opening. A configuration for realizing this logic is shown in FIG. 5B.

  When there is an operation command and there is no failure (normal), the circuit breaker operation determining means 44 outputs the circuit breaker closing / opening signal LBoff = “CLOSE” and switches on the circuit breaker 4. Once the circuit breaker 4 is turned on by the operation command, the circuit breaker 4 may be turned on even when there is no operation command, or it is turned on when there is an operation command, and opened when there is no operation command. It is also good. When the output of the failure determination means 23 is “L” (there is a failure), the circuit breaker closing / opening signal LBoff = “OPEN” is output, and the circuit breaker 4 is opened. A configuration for realizing this logic is shown in FIG. 6B.

  In the AND logic gate 24 of FIG. 6A, only when the operation command and the output of the failure determination means are input and there is an operation command (“H”) and the output of the failure determination means is normal (“H”), “H” Is output to the gate start / stop control unit 28, and even if there is an operation command (“H”), if the output of the failure determination means is a failure (“L”), “L” is output to the gate start / stop control unit 28. To do. The gate start / stop control unit 28 outputs GST = “L” to the PWM gate pulse generation / gate logic unit 29 when the output signal of the AND logic gate 24 or other warning signal is “L”, and the inverter 10 is turned on. Turn off. Thus, when it is determined that the failure is detected by the failure determination means 23, the gate is stopped, the inverter is turned off, and the opening contactor 11 and the disconnector 4 are opened.

(effect)
In this embodiment, when a failure is detected, the inverter is turned off and the opening contactor and the current breaker are opened to disconnect the inverter and the motor, and between the inverter side including the filter capacitor and the overhead line side. Is also cut off. Therefore, when the motor is rotating at a high speed, the inverter can be protected from the induced voltage generated by the motor, and the inverter can be protected by avoiding unnecessary power input and output with the overhead line side. Thus, the reliability of the apparatus can be further improved.

[Eighth embodiment]
The configuration of the eighth embodiment of the electric vehicle control apparatus 100 according to the present invention will be described with reference to the control block diagram of FIG. 8A.

  The same elements as those in FIG. 4A are denoted by the same reference numerals and description thereof is omitted, and only different parts are described here. That is, as shown in FIG. 8A, the control block according to the present embodiment adds a temperature estimation unit 31 instead of the no-load induced voltage characteristic calculation unit 40 in FIG. 4A, and estimates the output that is the output of the temperature estimation unit 31. The temperature TEMP is input to the failure determination means 33. Next, the operation of this embodiment will be described.

(Function)
The temperature estimation means 31 receives the motor frequency ωmot, which is the output of the motor frequency calculation unit 38, and the motor voltage Vuv, which is the output of the voltage sensor 36, and estimates the temperature of the motor by the temperature estimation means shown in FIG. 8B.

  FIG. 8B shows the relationship between the motor frequency ωmot and the motor voltage Vuv. When the motor temperature is low, the relationship between ωmot and Vuv is previously stored as table data for each motor temperature as indicated by a dotted line “A” (motor temperature = TEMP_A) and when the motor temperature is high, as indicated by a dotted line “C” (motor temperature = TEMP_C). Remember. The temperature estimation means 31 receives ωmot and Vuv as inputs and determines the corresponding motor temperature. That is, if the motor frequency at a certain motor temperature is ω mot1 and the motor voltage at that time is V uv1, the temperature estimating means 31 is a dotted line with ω mot = ω mot 1 and V uv = V uv 1 from the table data stored for each motor temperature. The motor temperature corresponding to “B” = TEMP_B is determined.

The failure determination means 23 receives the motor temperature TEMP, which is the output of the temperature estimation means 31, and the gate start / stop signal GST, which is the output of the gate start / stop control section 28, and the gate start / stop signal GST = “L” ( When the motor temperature TEMP is TEMP> reference temperature when the inverter 10 is off, it is determined that the motor is overtemperature, that is, a failure, and “L” is output to the AND logic gate 24.

When TEMP ≦ reference temperature, it is determined that the motor is within the normal operating temperature range, that is, normal, and “H” is output to the AND logic gate 24.

  The operation command signal is input to the AND logic gate 24 as “H” when there is an operation command and “L” when there is no operation command. In the AND logic gate 24, the operation command signal and the output of the failure determination means are input, and “H” is gated only when there is an operation command (“H”) and the output of the failure determination means is normal (“H”). If the output of the failure determination means is a failure (“L”) even if there is an operation command (“H”), “L” is output to the gate start / stop control unit 28.

  The gate start / stop control unit 28 generates a PWM gate pulse by generating a gate start / stop signal GST = “H” when the output signal of the AND logic gate 24 is “H” and other warning signals are “H” (normal). Output to the gate logic unit 29. The gate start / stop control unit 28 outputs GST = “L” to the PWM gate pulse generation / gate logic unit 29 when the output signal of the AND logic gate 24 or other warning signal is “L”.

  As described above, when the motor temperature TEMP is higher than the reference temperature based on the output of the failure determination means, it is determined as a failure. If it is determined that there is a failure, the three-phase gate signals VuINV, VvINV, and VwINV are not output as a gate stop even if the operation command is changed, and the inverter 10 remains off.

  The reference temperature is set to the maximum operating temperature of the motor to be applied. However, in consideration of an error in the motor frequency calculation unit 38 due to an offset or noise in the voltage sensor 36, (maximum operating temperature + α) ° C. It is good also as the above setting value. α ° C is a value determined by the applied electric motor. In addition, the motor frequency calculation unit 38 obtains the motor frequency ωmot calculated by the motor voltage Vuv (voltage between UVs) obtained from the voltage sensor 36. As the motor voltage obtained by the voltage sensor 36, Vvw (between VW) Voltage) or Vwu (voltage between WUs) may be used. Similarly, Vvw (voltage between VW) or Vwu (voltage between WU) may be used for the motor voltage input to the temperature estimation means 31.

  FIG. 8C is a diagram illustrating a configuration example of the failure determination unit 23 according to the present embodiment.

  The comparator 304 compares the motor temperature TEMP with a temperature threshold, and outputs “H”, for example, when the motor temperature TEMP exceeds the reference temperature. Here, the reference temperature is set to the maximum operating temperature of the motor + α. The delay circuit 302 outputs “H” (failure) when “H” input from the comparator 301 continues for a predetermined time. Therefore, for example, even if the motor temperature TEMP includes noise and the comparator 301 outputs “H” instantaneously, it is not determined as a failure, and is determined as a failure only when the high temperature state of the motor continues for a predetermined time. Is done.

(effect)
In the present embodiment, the motor temperature is estimated based on the motor voltage and motor frequency obtained from the voltage sensor while the gate is off, that is, the inverter is off. When the motor temperature is higher than the reference temperature, a failure determination is output. It is possible to reliably determine the overtemperature, and to stop protection early. That is, the reliability of the apparatus can be increased. In addition, the motor temperature can be estimated without using the temperature sensor, speed sensor, and rotor position sensor for detecting the motor temperature, so the number of parts is reduced, reliability is improved, sensor wiring is not required, and maintenance is performed. Advantages such as improved performance can also be obtained. In addition, by attaching a voltage sensor between the contactor for opening and the permanent magnet synchronous motor, even when the contactor for opening is opened due to failure / protection operation, the motor voltage and motor frequency obtained from the voltage sensor The motor temperature is always estimated, and when the motor temperature is higher than the reference temperature, the motor overtemperature can be detected, so that an advantage of improving reliability can be obtained.

  The above description is an embodiment of the present invention, and does not limit the apparatus and method of the present invention, and various modifications can be easily implemented.

It is a control block diagram which shows the structure of 1st Example of the electric vehicle control apparatus by this invention. It is a figure which shows the voltage signal Vuv between UV. It is a block diagram which shows the structure of the Example of the failure determination means 23 which concerns on 1st Example. It is a graph which shows the relationship between vehicle speed V_MON and reference | standard speed difference (DELTA) Vref. It is a control block diagram which shows the structure of 2nd Example of the electric vehicle control apparatus by this invention. It is a control block diagram which shows the structure of 3rd Example of the electric vehicle control apparatus by this invention. It is a block diagram which shows the structure of the failure determination means 23 which concerns on 3rd Example. It is a graph which shows the relationship between frequency (omega) _MON and reference | standard frequency difference (DELTA) omegaef. It is a control block diagram which shows the structure of 4th Example of the electric vehicle control apparatus by this invention. It is a graph which shows an example of a no-load induced voltage characteristic. It is a control block diagram which shows the structure of 5th Example of the electric vehicle control apparatus by this invention. It is a logic diagram which shows the determination operation | movement of the contactor for opening. It is a control block diagram which shows the structure of 6th Example of the electric vehicle control apparatus by this invention. It is a logic diagram which shows the determination operation | movement of a circuit breaker. It is a control block diagram which shows the structure of 7th Example of the electric vehicle control apparatus by this invention. It is a control block diagram which shows the structure of 8th Example of the electric vehicle control apparatus by this invention. It is a figure for demonstrating operation | movement of a temperature estimation means. It is a figure which shows the structural example of the failure determination means 23 which concerns on 8th Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pantograph 4 ... Breaker 6 ... Smoothing reactor 9 ... Filter capacitor 10 ... Inverter 11 ... Opening contactor 12 ... Permanent magnet synchronous motor 20 ... Entire control block 21 ... Torque pattern generation unit 23 ... Failure determination means 24 ... AND logic gate 26 ... Vector control unit 28 ... Gate start / stop control unit 29 ... PWM gate pulse generation Gate logic unit 30 ... current sensor 31 ... temperature estimation unit 33 ... magnetic flux correction unit 36 ... voltage sensor 37 ... motor speed calculation unit 38 ... motor frequency calculation unit 39 ... estimation Frequency calculation unit 40 ... no-load induced voltage characteristic calculation unit 42 ... transmission line 43 ... open contactor operation determination means 44 ... breaker operation determination means

Claims (12)

An inverter that converts power from direct current to alternating current;
A permanent magnet synchronous motor driven by AC power supplied from the inverter;
A voltage sensor for detecting a motor voltage of the permanent magnet synchronous motor;
An electric vehicle control device comprising failure determination means for determining failure of the motor based on the motor voltage. The failure determination means includes speed calculation means for calculating an electric vehicle speed from an electric motor voltage detected by the voltage sensor,
2. The electric vehicle according to claim 1, wherein when the difference between the electric vehicle speed obtained from the outside of the control device and the calculated electric vehicle speed is larger than a reference speed difference, a failure determination signal is output. Control device.   The electric vehicle control device according to claim 2, wherein the reference speed difference is a value that increases in accordance with an increase in the electric vehicle speed obtained from the outside of the control device. The failure determination means is a frequency for estimating the rotation frequency of the motor from a motor frequency calculation means for calculating a motor rotation frequency from the motor voltage detected by the voltage sensor and a signal including a three-phase voltage command for the inverter. An estimation means,
The failure determination signal is output when a difference between the motor rotation frequency calculated by the motor frequency calculation means and the motor rotation frequency estimated by the frequency estimation means is larger than a reference frequency difference. The electric vehicle control apparatus according to 1. The failure determination means is a frequency for estimating the rotation frequency of the motor from a motor frequency calculation means for calculating a motor rotation frequency from the motor voltage detected by the voltage sensor and a signal including a three-phase voltage command for the inverter. An estimation means, and a calculation means for calculating a rotation frequency of the electric motor from an electric vehicle speed obtained from the outside of the control device,
The difference between the motor rotation frequency calculated by the calculation means and the motor rotation frequency calculated by the motor frequency calculation means, or the motor rotation frequency calculated by the calculation means and the motor rotation estimated by the frequency estimation means The electric vehicle control device according to claim 1, wherein the failure determination signal is output when a difference from the frequency is larger than a reference frequency difference.   6. The electric vehicle control device according to claim 5, wherein the reference frequency difference is a value that increases in accordance with an increase in electric vehicle speed obtained from the outside of the control device. The failure determination means includes a motor frequency calculation means for calculating a motor rotation frequency from the motor voltage detected by the voltage sensor, and a no-load induced voltage calculation for calculating a no-load induction voltage of the motor from the motor rotation frequency. Means and
If the difference between the no-load induced voltage calculated by the no-load induced voltage calculation means and the motor voltage obtained from the voltage sensor is greater than a reference voltage difference when the inverter is not operating, the failure determination The electric vehicle control device according to claim 1, wherein the electric vehicle control device outputs a signal. An opening contactor for opening / connecting between the inverter and the electric motor;
The electric vehicle control device according to claim 1, wherein the failure determination unit opens the contactor for opening when determining a failure. A current breaker for connecting / opening between the inverter and the overhead wire side;
The electric vehicle control device according to claim 1, wherein the failure determination unit opens the circuit breaker when a failure is determined. The electric vehicle control device according to claim 6,
A current breaker for connecting / opening between the inverter and the overhead wire side;
9. The electric vehicle control device according to claim 8, wherein the failure determination means opens the contactor for opening and the breaker when determining a failure. The failure determination means indicates, for each motor temperature, a motor frequency calculation means for calculating a motor rotation frequency from the motor voltage detected by the voltage sensor, and a relationship between the effective value of the motor voltage and the frequency of the motor voltage. Temperature estimation means for estimating the temperature of the electric motor with reference to the table data from the motor rotation frequency calculated by the electric motor frequency calculation means.
2. The electric vehicle control device according to claim 1, wherein when the inverter is not in operation, a failure determination signal is output when the temperature of the electric motor estimated by the temperature estimation unit is higher than a reference temperature.   12. The electric vehicle control device according to claim 1, wherein the voltage sensor is attached between the contactor for opening and the permanent magnet synchronous motor.

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