JP2015050854A - Electrical vehicle controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical vehicle controller capable of downscaling an overall apparatus that drives a permanent magnet synchronous motor.SOLUTION: An electrical vehicle controller includes: a VVVF inverter 21 that generates AC electric power for driving a permanent magnet synchronous motor 2 from supplied DC power; and capacitors (13, 16) provided on a DC side of the VVVF inverter 21, each of the capacitors having a rated voltage equal to or higher than a voltage applied by causing a fly-wheel diode of the VVVF inverter 21 to full-wave rectify an induced voltage of the permanent magnet synchronous motor 2 generated when the permanent magnet synchronous motor 2 rotates at a highest number of revolutions.

Description

Embodiments described herein relate generally to an electric vehicle control apparatus.

  In general, a permanent magnet synchronous motor (PMSM) can use energy more efficiently than an induction motor, and can easily be reduced in weight because it generates less heat. Therefore, in recent years, the demand for permanent magnet synchronous motors has increased.

  In such a permanent magnet synchronous motor, since it is necessary to control by applying a voltage from the VVVF inverter according to the rotation of the rotor of each permanent magnet synchronous motor, individual control corresponding to each permanent magnet synchronous motor is required. It is. For this reason, a dedicated VVVF inverter is disposed for each permanent magnet synchronous motor (see, for example, Patent Document 1).

  In addition, a technology is disclosed that enables downsizing of the entire apparatus by adopting a configuration in which four inverters that drive a permanent magnet synchronous motor are attached to one cooler (see, for example, Patent Document 2).

JP 2005-328619 A JP2011-229372A

  By the way, even if the inverter breaks down for some reason and the output voltage of the inverter becomes uncontrollable, the vehicle travels by driving another electric motor provided in the vehicle or is pulled by another power vehicle. When the vehicle travels, the electric motor connected to the failed inverter also rotates with the rotation of the wheels.

  At this time, since an induced voltage is generated from the motor, the induced voltage is applied from the motor between the terminals of the inverter, and the induced voltage, that is, in the IGBT module, is applied to components such as a capacitor provided on the DC side of the inverter of the main circuit. A full-wave rectified voltage is applied by the provided diode. When the vehicle travels at a high speed and the number of revolutions of the electric motor increases, for example, damage to the filter capacitor, burnout of the discharge resistance, and the like occur due to continuous application of a voltage exceeding the rating.

  For this reason, conventionally, a three-phase contactor that electrically opens the inverter and the motor is provided so that the induced voltage of the motor is not pressurized by the inverter. Since this three-phase contactor needs to be provided between each motor and the inverter, for example, a four-in-1 VVVF inverter needs to be provided with four three-phase load contactors. The presence of the three-phase contactor has led to an increase in the outer shape of the inverter that drives the permanent magnet synchronous motor, and has been a factor that increases the cost.

  The present application has been made in view of such circumstances, and an object thereof is to provide an electric vehicle control device that enables downsizing of the entire device that drives a permanent magnet synchronous motor.

  According to an embodiment of the present invention for solving the above-described problem, a VVVF inverter that generates AC power for driving a permanent magnet synchronous motor from supplied DC power, and a DC side of the VVVF inverter are provided. And the capacitor has an induced voltage of the motor that is generated when the permanent magnet synchronous motor rotates at the maximum rotation speed is equal to or higher than a voltage that is full-wave rectified and pressurized by the flywheel diode of the VVVF inverter. An electric vehicle control device having a rated voltage is provided.

The figure which shows the structure of the electric vehicle control apparatus of 1st Embodiment. The figure for demonstrating the selection method of the discharge resistance of the electric vehicle control apparatus of 1st Embodiment. The figure which shows the structure of the electric vehicle control apparatus of 2nd Embodiment. The time chart for demonstrating the operation | movement at the time of the VVVF inverter non-operation of the electric vehicle control apparatus of 2nd Embodiment.

[First embodiment]
FIG. 1 is a diagram illustrating a configuration of the electric vehicle control device according to the first embodiment.

  DC power from a power source such as an overhead wire or a third rail is supplied to the electric vehicle control device 100 via the current collector 4. The electric vehicle control apparatus 100 converts the supplied DC power into three-phase AC power by the inverter unit 1 and drives the permanent magnet synchronous motor 2.

  The DC overhead power supplied from the current collector 4 is input to the high-speed circuit breaker 5. In the subsequent stage of the high-speed circuit breaker 5, the overhead line power is branched into two power lines. One power line is supplied to the next stage through an open contactor (LB1) 8, a charging resistor 7, and a filter reactor 9 connected in series. Here, a charging resistor short-circuit contactor (LB2) 6 is connected in parallel with the charging resistor 7. The other power line is supplied to the next stage via an overhead wire voltage detector (DCPT) 19 and connected to the wheel 12 which is a ground terminal.

  A DC side core is provided at the subsequent stage of the filter reactor 9. The DC side core is a circuit element for removing noise included in DC power. This DC side core is not an essential circuit element, and may not be provided when there is little noise included in DC power.

  An overvoltage suppression circuit 14 is provided at the subsequent stage of the DC side core (the side opposite to the side where the filter reactor 9 is provided). An overvoltage suppression resistor 10 and an overvoltage suppression switching element 11 are connected to the overvoltage suppression circuit 14 in series. These are resistors and thyristors for discharging and suppressing overvoltage, respectively.

  A DC filter capacitor 13 and a filter capacitor voltage detector (DCPT) 20 are provided following the overvoltage suppression circuit 14. The DC filter capacitor 13 is a main filter capacitor with a rating of 1800 V corresponding to the overhead line voltage, and its capacitance is about 5000 μF.

  A filter capacitor open contactor (LB3) 15 is provided in the subsequent stage of the DC filter capacitor 13 in series with the power line. The filter capacitor open contactor (LB3) 15 electrically disconnects the main circuit from the overhead line side and the inverter unit side during the protective operation of the inverter.

  A DC voltage detector (DCPT) 21 is connected to the subsequent stage (inverter unit side) of the filter capacitor open contactor (LB3) 15. Further, a discharge resistor 17 and a discharge resistor input switch 18 are connected in series at the subsequent stage. The discharge resistance input switch 18 is composed of a normally closed contact (closed when not energized and opened when energized), and when the filter capacitor open contactor (LB3) 15 is opened, the control power is turned off. Sometimes the discharge resistor 17 is connected to the circuit.

  An IGBT semiconductor element switching surge absorbing capacitor 16 and the inverter unit 1 are provided downstream of the discharge resistor 17 and the discharge resistor input switch 18. The IGBT semiconductor element switching surge absorbing capacitor 16 is a capacitor having a rating of 2500 V, and its capacitance is about 1000 μF.

  The inverter unit 1 is a 4-in-1 inverter, and is provided with four VVVF inverters 21a, 21b, 21c, and 21d connected in parallel. Permanent magnet synchronous motors 2a, 2b, 2c and 2d are connected to the AC side of the respective VVVF inverters 21a, 21b, 21c and 21d. In addition, current sensors 34a, 34b, 34c, 34d, 34e, 34f, 34g, and 34h are provided on the three-phase lines of the respective VVVF inverters 21a, 21b, 21c, and 21d.

  As shown in FIG. 1, the electric vehicle control device 100 includes an overall control unit 110. The overall control unit 110 controls the overall operation of the main circuit.

  Next, a configuration different from the conventional electric vehicle control device in the electric vehicle control device 100 of the first embodiment will be described.

  In the electric vehicle control apparatus 100 according to the first embodiment, four three-phase contactors that electrically open the inverter and the electric motor are not provided. As described above, this contactor is for protecting the device so that the induced voltage of the motor is not pressurized by the inverter. The electric vehicle control apparatus 100 according to the first embodiment is configured as follows in order to protect the inverter and to ensure the safety of the operator due to the absence of the four three-phase contactors. Yes.

(1) In the conventional electric vehicle control apparatus, one filter capacitor is provided, but in the first embodiment, the DC filter capacitor 13 for the DC filter circuit and the IGBT semiconductor element switching surge absorbing capacitor 16 are used. Has a system.

(2) In the first embodiment, a filter capacitor open contactor 15 is provided in the main circuit, and is operated so as to open and close when a protective operation of the inverter occurs.

(3) The discharge resistor 17 and the discharge resistor input switch 18 are provided, and the discharge resistor input switch 18 is operated at a predetermined timing to discharge the charge accumulated in the capacitor, thereby ensuring the safety of the operator.

[Operation at startup]
Next, an operation at the time of starting the electric vehicle control apparatus 100 according to the first embodiment will be described.

  When the start-up operation of the electric vehicle control device 100 is started, the high-speed circuit breaker 5 and the open contactor (LB1) 8 are connected, and the DC power is supplied from the current collector 4 to the high-speed circuit breaker 5 and the open contactor (LB1) 8. , And supplied through the charging resistor 7. At this time, since the filter capacitor open contactor 15 is connected, a DC current flows through the DC filter capacitor 13 and the IGBT semiconductor element switching surge absorbing capacitor 16 to perform charging. At this time, since the overvoltage suppressing switching element 11 and the discharge resistor input switch 18 are opened, DC power is not discharged from both capacitors.

  When it is detected by the filter capacitor voltage detector (DCPT) 20 and the DC voltage detector (DCPT) 21 that sufficient charge has been accumulated in the DC filter capacitor 13 and the IGBT semiconductor element switching surge absorbing capacitor 16. The charging resistor short-circuit contactor 6 is inserted. DC power from the current collector 4 is supplied to the inverter unit 1 through the high-speed circuit breaker 5, the charging resistor short-circuit contactor 6, the open contactor 8, the filter reactor 9 and the filter capacitor open contactor 15.

  When DC power is supplied to the inverter unit 1, DC power sent to the VVVF inverters 21a, 21b, 21c, and 21d is converted into AC power by the switching operation of the IGBT semiconductor element. The converted AC power is supplied to the permanent magnet synchronous motors 2a, 2b, 2c, and 2d, and driving of the permanent magnet synchronous motor 2 is started.

[Operation when the inverter is not operating: Serious failure, no-pressurization, etc.]
Next, the operation when the VVVF inverter of the electric vehicle control apparatus 100 of the first embodiment is not operating will be described. The VVVF inverter in the non-operating state is at least one VVVF inverter in the inverter unit 1. Therefore, the following description will be made without specifying the VVVF inverter.

  For example, when the electric vehicle is running and the VVVF inverter is in a non-operating state, for example, when the VVVF inverter fails and cannot operate (for example, at the time of a serious failure), or the control power supplied to the VVVF inverter is turned off. Therefore, it is a case where it cannot operate (for example, at the time of non-pressurized forwarding by traction). For example, the overall control unit 110 can determine that the VVVF inverter is in a non-operating state.

  When determining that the VVVF inverter is in a non-operating state, the overall control unit 110 opens (turns off) the filter capacitor open contactor 15. The filter capacitor open contactor 15 is opened (off) when the control power supply is turned off. Therefore, when the permanent magnet synchronous motors 2a, 2b, 2c, and 2d connected to the VVVF inverter are rotated by the vehicle being pulled by another vehicle, the IGBT semiconductor element switching surge absorbing capacitor 16 has The induced voltage generated from the permanent magnet synchronous motor is full-wave rectified and pressurized by the flywheel diode of the VVVF inverter. On the other hand, since the filter capacitor open contactor 15 is in the OFF state, the full-wave rectified voltage is not applied to the DC filter capacitor 13.

  Here, as described above, the conventional electric vehicle control apparatus includes one system of the filter capacitor, but in the first embodiment, the DC filter capacitor 13 for the DC filter circuit and the IGBT semiconductor element switching surge absorption Two systems of capacitors 16 are provided. The conventional filter capacitor has a rating of 1800 V, and its capacitance is about 6000 μF. In the first embodiment, the DC filter capacitor 13 is a main filter capacitor having a rating of 1800 V corresponding to the overhead line voltage, and its capacitance is 5000 μF. The IGBT semiconductor element switching surge absorbing capacitor 16 is a capacitor having a rating of 2500 V, and its capacitance is 1000 μF. A method for setting these capacitors will be described.

  In the first embodiment, by providing the filter capacitor open contactor 15, the DC filter capacitor 13 is configured to mainly pressurize the overhead wire voltage. Therefore, the rated voltage of the DC filter capacitor 13 is set to 1800 V, which is a voltage that can withstand a surge voltage generated in the overhead wire. Here, the rated voltage is the maximum allowable value of the voltage that can be continuously applied to both ends.

  Further, by providing the filter capacitor open contactor 15, the full-wave rectified voltage from the permanent magnet synchronous motor 2 mainly acts only on the IGBT semiconductor element switching surge absorbing capacitor 16. Accordingly, the IGBT semiconductor element switching surge absorbing capacitor 16 has a rated voltage of 2500 V that can withstand the voltage generated when full-wave rectification of the voltage between the motor terminals generated when the permanent magnet synchronous motor 2 rotates at the maximum speed. use.

  The capacitor capacity of the IGBT semiconductor element switching surge absorbing capacitor 16 is set to 1000 μF which is empirically used as a capacitor (phase capacitor) capacity for absorbing the IGBT semiconductor element switching surge. The capacity of the DC filter capacitor 13 was set to 5000 μF obtained by removing 1000 μF from the conventional filter capacitor capacity of 6000 μF.

  Here, when the rating of the conventional filter capacitor (6000 μF) is increased from 1800 V to 2500 V, the DC filter capacitor 13 (5000 μF, rating 1800 V) and the IGBT semiconductor element switching surge absorbing capacitor as in the first embodiment The increase / decrease in the size when dividing into 16 (1000 μF, rated 2500 V) will be described.

  In general, a capacitor having a small capacity has a high rated voltage, and a capacitor having a large capacity has a low rated voltage. Therefore, the rating of the IGBT semiconductor element switching surge absorbing capacitor 16 having a small capacitance of 1000 μF and thus a small size is 2500 V, rather than increasing the rating of the filter capacitor having a large capacitance of 6000 μF and therefore a large size from 1800 to 2500 V. This is advantageous because an increase in size can be suppressed.

  Further, since the size reduction by omitting the four three-phase load contactors can be realized, the size of the electric vehicle control device 100 can be greatly reduced as a whole.

  In FIG. 1, when it is determined that the VVVF inverter is in a non-operating state, the discharge resistance input switch 18 is further closed, and the discharge resistance 17 is connected to both ends of the IGBT semiconductor element switching surge absorbing capacitor 16. When the control power is off, the discharge resistance input switch 18 is closed because a normally closed contactor is used. For this reason, the discharge resistance input switch 18 is closed during non-pressurized feeding. While the vehicle is running, both the charging and discharging phenomenon occur in the IGBT semiconductor element switching surge absorbing capacitor 16, but when the vehicle stops, it accumulates in the IGBT semiconductor element switching surge absorbing capacitor 16 through the discharge resistor 17. The generated charge is discharged. Therefore, the safety of the worker can be achieved.

  While the vehicle is running and the permanent magnet synchronous motor 2 is rotating, the induced voltage generated between the terminals of the permanent magnet synchronous motor 2 is full-wave rectified through the flywheel diode of the VVVF inverter, and the DC voltage is the IGBT. The semiconductor element switching surge absorbing capacitor 16 and the discharge resistor 17 are continuously pressurized. Since an electric current flows through the discharge resistor 17 due to the induced voltage generated in the electric motor, the electric motor is in an electric power regenerative braking mode and a braking force is generated.

  However, the discharge resistor 17 uses a relatively high resistance of about 100 kΩ. Therefore, the current flowing through the discharge resistor 17 is small, and the loss generated in the discharge resistor 17 is also small. For example, if the full-wave rectified voltage generated by the flywheel diode of the VVVF inverter of the induced voltage generated in the permanent magnet synchronous motor 2 is about 2500 V, the loss generated in the discharge resistor 17 is 2500 V ^ 2/100 kΩ = 62.5 W It is. Since the maximum rating of the permanent magnet synchronous motor 2 is 100 kW or more, the loss generated in the discharge resistor 17 is 1/1000 or less than the maximum rating of the permanent magnet synchronous motor 2. Therefore, the braking force generated in the permanent magnet synchronous motor 2 by this current is so small that it does not matter.

  Here, the loss generated in the discharge resistor 17 is not limited to the above example, and it can be determined that there is no problem as long as it is 1/100 or less with respect to the maximum rating of the permanent magnet synchronous motor 2. It is necessary to consider not only the loss but also the external shape of the resistor and the discharge time.

  FIG. 2 is a diagram for explaining a method for selecting a discharge resistance of the electric vehicle control apparatus according to the first embodiment.

  The horizontal axis of the coordinate system shown in FIG. 2 indicates the resistance value of the discharge resistor 17, and the vertical axis indicates the outer size of the discharge resistor 17 and the discharge time.

  A curve A represents the relationship between the resistance value and the outer size. As the resistance value increases, the outer size decreases. Since a smaller outer size is desirable, for example, an outer size that is equal to or smaller than the threshold value THA is desirable. Here, the threshold value THA can be set to, for example, ½ of the size of the conventional overvoltage suppression resistor (OVRe).

  A curve B represents a relationship between the resistance value and the discharge time. As the resistance value decreases, the discharge time decreases. Since a shorter discharge time is desirable, for example, a discharge time that is equal to or less than the threshold THB is desirable. Here, as the threshold value THB, for example, discharge time = 5 minutes can be set.

  In FIG. 2, ranges of R1 to R2 are shown as resistance values that satisfy these two conditions. The resistance value = 100 KΩ of the discharge resistor 17 described above is a value existing in the section of R1 to R2 obtained from the relationship shown in FIG.

[Operation when VVVF inverter is temporarily stopped: minor failure]
Next, the operation | movement at the time of the temporary stop of the VVVF inverter of the electric vehicle control apparatus 100 of 1st Embodiment is demonstrated. Note that the VVVF inverter in the paused state is at least one VVVF inverter in the inverter unit 1. Therefore, the following description will be made without specifying the VVVF inverter.

  Examples of the case where the VVVF inverter is temporarily stopped while the electric vehicle is traveling include an abnormality in inverter control operation due to the occurrence of overvoltage in the main circuit, idling of the permanent magnet synchronous motor 2, and the like. Even if these abnormalities occur, they can be recovered by restarting them, so that they are recognized as temporary abnormalities (minor failures). Note that the occurrence of these abnormalities can be detected by the overall control unit 110.

  The operation when the VVVF inverter temporarily stops operating due to a minor failure will be described.

  For example, when the voltage value of the DC filter capacitor 13 becomes equal to or higher than the overvoltage detection level, the overall control unit 110 detects the occurrence of the abnormality via the filter capacitor voltage detector (DCPT) 20. The overall control unit 110 turns off the gate signal for the IGBT operation of the VVVF inverter and stops the VVVF inverter. Then, the overall control unit 110 opens the filter capacitor open contactor 15 to electrically disconnect the DC filter capacitor 13 from the VVVF inverter. As a result, the full-wave rectified value of the induced voltage from the permanent magnet synchronous motor 2 is not pressurized by the DC filter capacitor 13.

  At this time, the discharge resistance input switch 18 is kept open. The discharge resistor input switch 18 is connected to connect the discharge resistor 17 to the circuit when the VVVF inverter that has failed continuously is electrically released from the vehicle system, or when the vehicle control power is turned off and the VVVF inverter is turned off. This is limited to the case where is not operated continuously. The purpose of connecting the discharge resistor 17 to the circuit is that the vehicle travels by driving another power vehicle without the VVVF inverter operating, and the induced voltage of the permanent magnet synchronous motor 2 is applied to the IGBT semiconductor element switching surge absorbing capacitor 16. This is to ensure the safety of the operator by discharging the electric charge when the vehicle stops after being pressed.

  Subsequently, the overall control unit 110 turns on (conducts) the overvoltage suppression switching element 11 of the overvoltage suppression circuit 14. As a result, the overvoltage suppression resistor 10 is connected to the DC filter capacitor 13. Further, the overall control unit 110 opens the open contactor (LB1) 8 and the charging resistance short circuit contactor (LB2) 6. As a result, the DC filter capacitor 13 is electrically disconnected from the overhead wire, and the electric charge accumulated in the DC filter capacitor 13 is discharged through the overvoltage suppression resistor 10. This discharge operation is performed when an overvoltage is detected, and is not always performed when a minor failure occurs.

  When the vehicle is running, the induced voltage of the electric motor is full-wave rectified through the flywheel diode of the VVVF inverter, and this voltage is pressurized by the IGBT semiconductor element switching surge absorbing capacitor 16. The surge absorbing capacitor 16 has a rated voltage that is equal to or higher than the voltage at which the induced voltage of the motor generated when the permanent magnet synchronous motor 2 rotates at the maximum rotation speed is full-wave rectified and pressurized by the flywheel diode of the VVVF inverter. So no problem.

  Next, the operation when the VVVF inverter resumes operation will be described.

  When the operation start of the VVVF inverter is instructed, the open contactor (LB1) 8 is connected, and the DC power from the current collector 4 passes through the high-speed circuit breaker 5, the open contactor (LB1) 8, and the charging resistor 7. Supplied. As a result, the DC filter capacitor 13 is charged.

  When it is detected by the filter capacitor voltage detector (DCPT) 20 that the charging of the DC filter capacitor 13 is completed, the charging resistor short-circuit contactor 6 is turned on. DC power from the current collector 4 is supplied through a high-speed circuit breaker 5, a charging resistor short-circuit contactor 6, an open contactor 8, and a filter reactor 9. At this time, since the filter capacitor open contactor 15 is open, power from the overhead line is not supplied to the VVVF inverter.

  On the other hand, the overall control unit 110 detects the voltage of the IGBT semiconductor element switching surge absorbing capacitor 16 with a DC voltage detector (DCPT) 21. Then, the overall control unit 110 controls the operation of the VVVF inverter in accordance with the detected voltage. That is, the overall control unit 110 weakens the induced voltage of the permanent magnet synchronous motor 2 in the direction of lowering the induced voltage and causes the magnetic flux current to flow to lower the induced voltage. When the induced voltage is lowered, the full-wave rectified voltage is also lowered, so that the voltage of the IGBT semiconductor element switching surge absorbing capacitor 16 can be lowered.

  The overall control unit 110 controls the operation of the VVVF inverter so that the voltage of the IGBT semiconductor element switching surge absorbing capacitor 16 matches the voltage of the DC filter capacitor 13. When the voltages of the two capacitors match, the overall control unit 110 operates the filter capacitor open contactor 15 to connect the circuits. After that, it shifts to a normal motor control state.

  According to the first embodiment described above, since the three-phase load contactor provided for each of the permanent magnet synchronous motors on the AC side of the VVVF inverter is not required, the electric vehicle control device 100 can be reduced in size. And cost reduction. However, in place of the three-phase load contactor, a filter capacitor open contactor 15, an IGBT semiconductor element switching surge absorbing capacitor 16, its discharge resistor 17, and a discharge resistor input switch 18 are added on the DC side of the main circuit. However, since they require less space than four three-phase load contactors, the electric vehicle control apparatus 100 can be reduced in size as a whole.

[Second Embodiment]
In the second embodiment, the configuration of the main circuit is different from that of the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 3 is a diagram illustrating a configuration of the electric vehicle control device according to the second embodiment.

  As compared with the first embodiment, the circuit configuration of the electric vehicle control apparatus 100 according to the second embodiment is provided with a DC filter capacitor 13 in the immediate vicinity of the inverter unit 1, and an IGBT semiconductor element switching surge absorbing capacitor 16 and The combined point is different. In the second embodiment, the filter capacitor open contactor 15 and the DC voltage detector (DCPT) 21 are not provided.

  The capacity of the DC filter capacitor 13 shared with the surge absorbing capacitor is 6000 μF, which is the same as that of the conventional DC filter capacitor. The DC filter capacitor 13 is installed in the immediate vicinity of the VVVF inverter to absorb the IGBT semiconductor element switching surge voltage. The DC filter capacitor 13 has a rating of 2500V. This is because the DC voltage rating of the DC filter capacitor 13 requires that the induced voltage of the permanent magnet synchronous motor 2 be equal to or higher than the voltage value that is full-wave rectified through the flywheel diode of the VVVF inverter.

[Stop operation when VVVF inverter is not operating: Minor failure, major failure, no-pressurization, etc.]
Next, the stop operation when the VVVF inverter of the electric vehicle control apparatus 100 of the second embodiment is not operating will be described. The VVVF inverter in the non-operating state is at least one VVVF inverter in the inverter unit 1. Therefore, the following description will be made without specifying the VVVF inverter.

  When the electric vehicle is running and the VVVF inverter is in a non-operating state, for example, when the inverter control operation abnormality (light failure) is caused by the occurrence of overvoltage of the main circuit, idling of the permanent magnet synchronous motor 2, etc., VVVF This corresponds to the case where the inverter cannot be operated due to a failure (for example, during a serious failure), or the case where the inverter cannot be operated because the control power supplied to the VVVF inverter is turned off (for example, during non-pressurized forwarding by traction). For example, the overall control unit 110 can determine that the VVVF inverter is in a non-operating state.

  FIG. 4 is a time chart for explaining the operation of the electric vehicle control apparatus according to the second embodiment when the VVVF inverter is not operating.

  For example, when the voltage value of the DC filter capacitor 13 that was at the normal voltage value VNR at time T1 becomes a value equal to or greater than a certain value at time T2, for example, the voltage value VUL that should not be applied to the overhead wire, the overall control is performed. The unit 110 detects the occurrence of the abnormality via the filter capacitor voltage detector (DCPT) 20. The overall control unit 110 turns off the gate signal for the IGBT operation of the VVVF inverter and stops the VVVF inverter. Then, the overall control unit 110 turns on (conducts) the overvoltage suppression switching element 11 of the overvoltage suppression circuit 14, and the overall control unit 110 further opens the contactor (LB1) 8 and the charging resistor short-circuiting contactor (LB2) 6. And release.

  The overall control unit 110 turns on (conducts) the overvoltage suppressing switching element 11 because the response is faster than the open contactor (LB1) 8 and the charging resistor short-circuiting contactor (LB2) 6 so that the influence on the overhead line is minimized. This is to eliminate it. By this operation, the voltage accumulated in the DC filter capacitor 13 is discharged via the overvoltage suppression resistor 10. Then, the overall control unit 110 turns off (opens) the overvoltage suppression switching element 11 after the open contactor (LB1) 8 and the charging resistance short-circuiting contactor (LB2) 6 are opened at time T3.

  When the vehicle is running, the induced voltage of the permanent magnet synchronous motor 2 is applied to the DC filter capacitor 13 through the full-wave rectified voltage through the flywheel diode of the VVVF inverter and connected in parallel to the DC filter capacitor 13. The overvoltage suppression circuit is pressurized, and the overvoltage suppression resistor 10 consumes electric power due to the induced voltage from the permanent magnet synchronous motor 2. Therefore, if the overvoltage suppression resistor 10 continues to consume power from the permanent magnet synchronous motor 2 as it is, the overvoltage suppression resistor 10 will burn out.

  Therefore, after the open contactor (LB1) 8 is opened and the DC filter capacitor 13 is electrically disconnected from the overhead wire, the overvoltage suppression switching element 11 in the overvoltage suppression circuit 14 is turned off (opened), and the overvoltage The suppression resistor 10 prevents the energy due to the induced voltage from the permanent magnet synchronous motor 2 from being consumed continuously. In this way, the overvoltage suppression circuit 14 plays a role of reducing the voltage of the DC filter capacitor 13 until the open contactor 8 is opened to prevent the overvoltage from being applied to the overhead wire.

  Therefore, when the overvoltage suppression switching element 11 is turned off at time T3, the overvoltage suppression function is lost, and thus the voltage of the DC filter capacitor 13 rises again to the full-wave rectified voltage of the induced voltage from the motor. However, since the rating of the DC filter capacitor 13 is set to a value corresponding to this voltage, the element is not damaged.

[Restarting operation when VVVF inverter is not operating: minor failure]
In order to recover from a minor failure, when the operation start of the VVVF inverter is instructed, a voltage control operation for restart is performed in the period of time T3 to T4. Curve X in FIG. 4 shows the transition of the controlled voltage.

  The overall control unit 110 detects the voltage of the DC filter capacitor 13 by the filter capacitor voltage detector (DCPT) 20. Then, the overall control unit 110 controls the operation of the VVVF inverter in accordance with the detected voltage. That is, the overall control unit 110 weakens the induced voltage of the permanent magnet synchronous motor 2 in the direction of lowering the induced voltage and causes the magnetic flux current to flow to lower the induced voltage. When the induced voltage is lowered, the full-wave rectified voltage is also lowered, so that the voltage of the DC filter capacitor 13 can be lowered.

  The overall control unit 110 controls the operation of the VVVF inverter so that the voltage of the DC filter capacitor 13 matches the voltage of the overhead line voltage detector (DCPT) 19. At time T5, when the voltages of both capacitors match, the overall control unit 110 turns on the open contactor 8 and the charging resistor short-circuiting contactor 6 to electrically connect the overhead wire and the DC filter capacitor 13. After that, it shifts to a normal motor control state.

[Discharge operation when VVVF inverter is not operating: Serious failure, no-pressurization, etc.]
When the VVVF inverter is continuously stopped (during serious failure, no-pressurization forwarding, etc.), the restart operation is not performed. In order to ensure the safety of the operator, an operation of discharging the charge accumulated in the DC filter capacitor 13 is performed. Curve Y in FIG. 4 shows the transition of the controlled voltage.

  After the opening contactor 8 and the charging resistor short-circuiting contactor 6 are opened, the overall control unit 110 closes the discharging resistance input switch 18 and connects the discharging resistor 17 to the DC filter capacitor 13 at time T4. When the control power is off, the discharge resistance input switch 18 is closed because a normally closed contactor is used. For this reason, the discharge resistance input switch 18 is closed during non-pressurized feeding. While the vehicle is running, both the charging and discharging phenomenon occur in the DC filter capacitor 13, but when the vehicle stops, the electric charge accumulated in the DC filter capacitor 13 is discharged through the discharge resistor 17. Therefore, the safety of the worker can be achieved.

  While the vehicle is running and the permanent magnet synchronous motor 2 is rotating, the induced voltage generated between the terminals of the permanent magnet synchronous motor 2 is full-wave rectified through the flywheel diode of the VVVF inverter, and the DC voltage is The DC filter capacitor 13 and the discharge resistor 17 are continuously pressurized. Since an electric current flows through the discharge resistor 17 due to the induced voltage generated by the electric motor, the electric motor enters a power regenerative braking mode and generates a braking force.

  However, the discharge resistor 17 uses a relatively high resistance of about 100 kΩ. Therefore, the current flowing through the discharge resistor 17 is small, and the loss generated in the discharge resistor 17 is also small. For example, if the full-wave rectified voltage generated by the flywheel diode of the VVVF inverter of the induced voltage generated in the permanent magnet synchronous motor 2 is about 2500 V, the loss generated in the discharge resistor 17 is 2500 V ^ 2/100 kΩ = 62.5 W It is. Since the maximum rating of the permanent magnet synchronous motor 2 is 100 kW or more, the loss generated in the discharge resistor 17 is 1/1000 or less than the maximum rating of the permanent magnet synchronous motor 2. Therefore, the braking force generated in the permanent magnet synchronous motor 2 by this current is so small that it does not matter.

  According to the second embodiment described above, since the three-phase load contactor provided for each of the permanent magnet synchronous motors on the AC side of the VVVF inverter is not required, the electric vehicle control device 100 can be reduced in size. And cost reduction. However, in place of the three-phase load contactor, a DC filter capacitor 13 whose voltage rating is increased, its discharge resistor 17 and a discharge resistor input switch 18 are provided on the DC side of the main circuit. Since a small space is required compared with the phase load contactor, the electric vehicle control device can be downsized as a total.

[Summary]
The main contents and effects of the electric vehicle control device according to each embodiment described above will be listed.

(1) The electric vehicle control device of the present application is provided with a very small capacitor for absorbing a surge voltage generated when switching the element in the immediate vicinity of the IGBT semiconductor element on the DC side of the VVVF inverter, and is in contact with the overhead voltage side of the VVVF inverter. A DC filter capacitor is provided between the overhead line voltage and the newly provided contactor.

(2) Further, the capacitor for switching surge absorption of the IGBT semiconductor element provided in the immediate vicinity of the IGBT semiconductor element has all the induced voltage of the permanent magnet synchronous motor 2 generated when the permanent magnet synchronous motor 2 rotates at the maximum rotational speed. Use a rating that can withstand the voltage generated by wave rectification. Further, a switch for connecting the discharge resistor and the discharge resistor for discharging the electric charge accumulated in the surge voltage absorbing capacitor is provided.

(3) When the VVVF inverter fails, the contactor newly provided on the DC side of the VVVF inverter is opened. Even if the vehicle travels and the induced voltage of the permanent magnet synchronous motor 2 is full-wave rectified through the flywheel diode of the VVVF inverter, the voltage is not applied to the overhead line voltage side of the contactor, and the rated voltage is applied to the DC filter capacitor. It is possible to prevent the above voltage from being applied.

(4) Conventionally, a three-phase contactor is provided on the motor side of the VVVF inverter, and this three-phase load contactor has to be provided one by one for each permanent magnet synchronous motor. Therefore, for a 4-in-1 VVVF inverter, Although it was necessary to provide four three-phase load contactors, in the present application, since one contactor is provided on the DC side of the 4-in-1 VVVF inverter, the number of contactors can be reduced to 1/4. The electric vehicle control device can be reduced in size.

(5) In the present application, it is necessary to provide a capacitor for absorbing the switching surge of the IGBT semiconductor element in the immediate vicinity of the IGBT semiconductor element of the VVVF inverter, and further provide a discharge resistor for discharging the capacitor and a switch for connecting the discharge resistor. Although it is necessary, the capacitor for absorbing the surge voltage is about 1000 μF, which is one tenth of the capacity of the DC filter capacitor. However, it is possible to reduce the size compared to the configuration in which four conventional three-phase load contactors are provided.

Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage.
Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Inverter unit, 2 ... Permanent magnet synchronous motor, 4 ... Current collector, 5 ... High-speed circuit breaker, 6 ... Contact resistor for short circuit of charge resistance, 7 ... Charge resistor, 8 ... Open contactor, 9 ... Filter reactor, DESCRIPTION OF SYMBOLS 10 ... Overvoltage suppression resistor, 11 ... Overvoltage suppression switching element, 13 ... DC filter capacitor, 14 ... Overvoltage suppression circuit, 15 ... Filter capacitor open contactor, 16 ... IGBT semiconductor element switching surge absorption capacitor, 17 ... Discharge resistance DESCRIPTION OF SYMBOLS 18 ... Discharge resistance switch, 19 ... Overhead voltage detector, 20 ... Filter capacitor voltage detector, 21 ... DC voltage detector, 21 ... VVVF inverter, 100 ... Electric vehicle control apparatus, 110 ... General control part.

Claims (7)

A VVVF inverter that generates AC power for driving the permanent magnet synchronous motor from the supplied DC power;
A capacitor provided on the DC side of the VVVF inverter,
The capacitor has a rated voltage that is equal to or higher than a voltage in which an induced voltage of the motor generated when the permanent magnet synchronous motor rotates at the maximum rotational speed is full-wave rectified and pressurized by a flywheel diode of a VVVF inverter. Car control device. Another capacitor provided in parallel on the opposite side of the capacitor from the VVVF inverter;
A contactor that is provided between the capacitor and the other capacitor and interrupts electrical connection between the capacitors;
An overall control unit for controlling the operation of the electric vehicle control device;
The overall control unit controls the contactor so that the full-wave rectified voltage generated by the flywheel diode of the VVVF inverter generated by the permanent magnet synchronous motor is not applied to the other capacitor when the VVVF inverter is stopped. The electric vehicle control device according to claim 1, wherein the electric vehicle control device is opened. A discharge resistor provided in parallel with the capacitor, and a switch for connecting or disconnecting the discharge resistor to a circuit on the DC side of the VVVF inverter;
The integrated control unit operates the switch to connect a discharge resistance to a DC side circuit of the VVVF inverter when the VVVF inverter is continuously stopped due to a serious failure or no-pressurization forwarding. 2. The electric vehicle control device according to 2.   The loss generated in the discharge resistor when a full-wave rectified voltage of the flywheel diode of the VVVF inverter of the induced voltage generated in the permanent magnet synchronous motor is applied is 1/100 or less of the maximum rating of the permanent magnet synchronous motor. The electric vehicle control device according to claim 3, wherein A discharge resistor provided in parallel with the capacitor and a switch for connecting or disconnecting the discharge resistor to a circuit on the DC side of the VVVF inverter;
An overall control unit for controlling the operation of the electric vehicle control device;
The integrated control unit operates the switch to connect a discharge resistance to a DC side circuit of the VVVF inverter when the VVVF inverter is continuously stopped due to a serious failure or no-pressurization forwarding. 4. The electric vehicle control device according to 4.   The loss generated in the discharge resistor when a full-wave rectified voltage of the flywheel diode of the VVVF inverter of the induced voltage generated in the permanent magnet synchronous motor is applied is 1/100 or less of the maximum rating of the permanent magnet synchronous motor. The electric vehicle control device according to claim 5, wherein   The switch that connects or disconnects the discharge resistor to the DC side circuit of the VVVF inverter is a normally closed switch that connects to the DC side circuit when power for controlling the VVVF inverter is not supplied. The electric vehicle control device according to claim 4 or 6.

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