JP6584822B2 - Vehicle control apparatus and method - Google Patents

Description

  Embodiments described herein relate generally to a vehicle control apparatus and method.

In general, in railway vehicles, DC power or AC power supplied from an overhead wire is used to drive an electric motor for power to be mounted.
The electric power supplied from the overhead line is not used as it is, but is converted into electric power by the vehicle control device (power conversion device) mounted on the railway vehicle and supplied to the electric motor.
This vehicle control device includes a plurality of switching elements, and performs power conversion by switching operations of these switching elements to supply stable power.

  For example, it is converted into DC power having a stable voltage by a converter (AC / DC conversion circuit) via a transformer that receives power from the AC overhead wire.

  A variable voltage-variable frequency inverter is connected to the subsequent stage of the converter.

JP 2007-151392 A

In the above-described vehicle control device, during the power conversion operation, the transformer and the converter are each accompanied by a temperature increase due to various losses such as switching loss.
By the way, if at least one of the transformer or the converter is in an overtemperature state due to a temperature rise, it may be difficult to continue the operation of the train.
Therefore, there has been a demand for a vehicle control device that can stably travel a railway vehicle.

The transformer of the vehicle control device of the embodiment receives supply of AC power from the AC overhead line, performs voltage conversion, and outputs the AC power to the converter.
The converter performs AC / DC conversion of the input AC power and outputs it to the inverter.
The inverter performs DC / AC conversion and supplies the output of the converter to the load.
At this time, the control unit, as temperature of the transformer does not exceed a predetermined allowable temperature, and, as a transformer in the load is reduced, and controls the operating state of the converter.

FIG. 1 is a schematic configuration block diagram of a railway vehicle control apparatus according to an embodiment. FIG. 2 is a schematic configuration diagram of the converter. FIG. 3 is a schematic configuration diagram of the inverter. FIG. 4 is a process flowchart of the control unit of the first embodiment. FIG. 5 is a process flowchart of the control unit of the second embodiment.

Hereinafter, embodiments will be described with reference to the drawings.
[1] First Embodiment FIG. 1 is a block diagram of a schematic configuration of a vehicle control device mounted on a railway vehicle according to an embodiment.
The vehicle control device 10 is connected between the secondary winding 20-2 of the transformer 20 and is provided between a converter 21 that converts AC power supplied via the transformer 20 into DC power, and an output terminal of the converter 21. Is connected to the filter capacitor 22 for removing the harmonic current and the converter 21 via a DC circuit, converts the DC power input from the converter 21 into three-phase AC power, and outputs it to the three-phase AC motor M. And an inverter 23.

  The primary winding 20-1 of the transformer 20 is connected in series with the pantograph 16, the high-speed circuit breaker 19, and the wheel 18 that is grounded (low potential side power source) via the line 17. AC power from the overhead wire (AC feeder) 15 (high potential side power source) is supplied to the primary side winding 20-1 of the transformer 20 via the high-speed circuit breaker 19.

Here, the converter 21 basically operates at a high carrier frequency, but is configured to be able to change the carrier frequency, the number of pulses, or the pulse switching frequency in accordance with the load ratio with the transformer 20 of the converter 21. ing. Control of the carrier frequency, the number of pulses, or the pulse switching frequency in the converter 21 corresponds to control of the operation state.
Further, the inverter 23 switches the pulse mode according to the rotational speed of the three-phase AC motor and is used even in a state where the carrier frequency is low. This is to cope with a case where a large current is temporarily required, such as gradient activation.

  Further, an AC circuit breaker 24 is connected in series to the secondary winding 20-2 of the transformer 20, and the charging resistor 25 and the charging resistor 25 connected in series are connected in parallel to the AC circuit breaker 24. A charging resistor connection contactor 26 is provided for electrical connection to the secondary winding 20-2.

  Further, the vehicle control device 10 detects the temperature of each part of the vehicle control device 10, particularly the control unit 27 that controls the converter 21 and the inverter 23, and the transformer 20, and outputs a transformer temperature detection signal TT to the control unit 27. A first temperature sensor 28 and a second temperature sensor 29 that detects the temperature of the converter 21 (particularly a switching element described later) and outputs a converter temperature detection signal TC to the control unit 27 are provided. Note that the first temperature sensor 28 is not necessarily included in the vehicle control device 10 and may be configured to receive the transformer temperature detection signal TT from the outside.

FIG. 2 is a schematic configuration diagram of the converter.
In the above configuration, the converter 21 includes switching elements 31H1 and 31H2 constituting the upper arm and switching elements 31L1 and 31L2 constituting the lower arm, as shown in FIG. Here, the switching elements 31H1 and 31H2 and the switching elements 31L1 and 31L2 are made of a silicon carbide (SiC: silicon carbide) semiconductor or a gallium nitride (GaN: GaN) semiconductor, which is a material having a wider band gap than silicon (Si). (Gallium nitride) semiconductor.
Accordingly, it is possible to operate at a higher switching frequency and to reduce noise compared to a semiconductor formed of silicon.

Further, the reverse conducting diode 32H1 is connected in parallel to the switching element 31H1, the reverse conducting diode 32H2 is connected in parallel to the switching element 31H2, the reverse conducting diode 32L1 is connected to the switching element 31L1, and the switching element 31L2 Is connected with a reverse conducting diode 32L2.
These reverse conducting diodes 32H1, 32H2, 32L1, and 32L2 are also formed of silicon carbide or gallium nitride, which is a material having a wider band gap than silicon (Si). For this reason, when these reverse conducting diodes 32H1, 32H2, 32L1, and 32L2 function as so-called flywheel diodes, it is possible to increase the cutoff current of the switching elements 31H1, 31H2, 31L1, and 31L2.

FIG. 3 is a schematic configuration diagram of the inverter.
On the other hand, in the inverter 23, a U-phase arm unit 41U, a V-phase arm unit 41V, and a W-phase arm unit 41W are connected in parallel between the high potential side DC power supply line PHL and the low potential side DC power supply line PLL. The phase arm unit 41U, the V phase arm unit 41V, and the W phase arm unit 41W are connected to the three-phase AC motor M via the U phase output line 23U, the V phase output line 23V, and the W phase output line 23W, respectively. .

  The U-phase arm portion 41U includes a U-phase upper arm portion 44UU having an upper switching element 42UH and a reverse conducting diode 43UH connected in parallel to the upper switching element 42UH, a lower switching element 42UL, and the lower switching element And a U-phase lower arm portion 44UL having a reverse conducting diode 43UL connected in parallel to 42UL.

  The V-phase arm portion 41V includes a V-phase upper arm portion 44VU having an upper switching element 42VH and a reverse conducting diode 43VH connected in parallel to the upper switching element 42VH, a lower switching element 42VL, and the lower switching element And a V-phase lower arm portion 44VL having a reverse conducting diode 43VL connected in parallel to 42VL.

  The W-phase arm portion 41W includes a W-phase upper arm portion 44WH having an upper switching element 42WH and a reverse conducting diode 43WH connected in parallel to the upper switching element 42WH, a lower switching element 42WL, and the lower switching element And a W-phase lower arm portion 44WL having a reverse conducting diode 43WL connected in parallel to 42WL.

  In the above configuration, each switching element constituting the converter 21 and the inverter 23 is configured as, for example, an IGBT.

Next, the operation of the first embodiment will be described.
When AC power is supplied from the AC overhead wire 15 to the primary winding 20-1 of the transformer 20 of the vehicle control device 10 via the pantograph 16 and the high-speed circuit breaker 19, the control unit 27 causes the AC circuit breaker 34 to be connected. Prior to setting the closed state (on state), the charging resistor connecting contactor 36 is set to the closed state (on state).

As a result, the current of the AC power supplied via the charging resistor 35 is full-wave rectified by the reverse conducting diodes 32H1, 32H2, 32L1, and 32L2 constituting the converter 21, and charges the filter capacitor 22.
When the charging of the filter capacitor 22 is completed, the AC power current is minute or no longer flows. As a result, a large current does not flow even when the AC circuit breaker 24 is closed (on state), and for example, the reverse conducting diodes 32H1, 32H2, 32L1, and 32L2 are prevented from being destroyed.
Thereafter, the converter 21 can be supplied with high power from the AC overhead wire (AC feeder) 15, and the converter 21 is supplied with AC power (for example, 1500 V) from the secondary winding 20-2 of the transformer 20. Is done.

Thereby, the converter 21 converts the input AC power into DC power and outputs it from the output terminal.
The filter capacitor 22 provided between the output terminals of the converter 21 removes the harmonic current from the DC power output from the converter 21 and outputs it to the inverter 23.

The inverter 23 converts the input DC power into three-phase AC power and drives the three-phase AC motor M.
More specifically, three-phase AC power having a voltage and frequency based on a PWM control signal (not shown) output from the control unit 27 is output to the three-phase AC motor M.

FIG. 4 is a process flowchart of the control unit of the first embodiment.
In parallel with the power conversion operation, the control unit 27 corresponds to the temperature of the transformer 20 corresponding to the transformer temperature detection signal TT output from the first temperature sensor 28 and the converter temperature detection signal TC output from the second temperature sensor 29. The temperature of the converter 21 to be monitored is monitored (step S11).

Next, the control unit 27 determines whether or not the temperature of the transformer 20 is likely to exceed an allowable value (step S12).
Here, when the temperature of the transformer 20 is likely to exceed the allowable value, for example, when the current temperature increase rate continues from the current temperature of the transformer 20, the temperature of the transformer 20 becomes a predetermined threshold temperature after a predetermined time. This is a case where (= allowable value) is predicted to be exceeded (hereinafter the same).
If it is determined in step S12 that the temperature of the transformer 20 is unlikely to exceed the allowable value (step S12; No), the control unit 27 proceeds to step S11 again and enters a standby state. The process will be repeated.

If it is determined in step S12 that the temperature of the transformer 20 is likely to exceed the allowable value (step S12; Yes), the control unit 27 determines whether or not the temperature of the converter 21 has a margin (step S13). .
Here, whether or not the temperature of the converter 21 has a margin is determined by, for example, performing a control change such as increasing the carrier frequency, the number of pulses or the pulse number switching frequency to reduce the loss in the transformer 20 and the temperature of the transformer 20. Whether or not the temperature of the converter 21 can be maintained below a predetermined threshold temperature even when the converter 21 is continuously controlled so that the output current of the transformer 20 approaches a sine waveform so as to reduce the (The same applies hereinafter).

  In the determination of step S13, when the control of the converter 21 is assumed and the transformer temperature is likely to exceed the allowable value (step S13; No), the control unit 27 returns the process to step S11 again. The process shifts to a standby state, and thereafter the same processing is repeated.

  In the determination of step S13, when the control of the converter 21 is assumed and the temperature of the transformer does not exceed the allowable value (step S13; Yes), the control unit 27 controls the assumed converter 21. (Carrier frequency control, pulse number control, pulse switching frequency control, etc.) are performed, and the process is terminated (step S14).

  As described above, according to the first embodiment, when the temperature of the transformer 20 is likely to exceed the allowable value and the temperature of the converter 21 has a margin, the converter 21 is more loaded. By performing high control (control to increase the carrier frequency, increase the number of pulses, or increase the pulse switching frequency, the converter 21 bears more burden and reduces the loss of the transformer 20), the output of the transformer 20 Since it becomes possible to drive the transformer 20 by reducing the loss of the transformer 20 by approximating the current to a sine waveform, the vehicle control device 10 is stopped, the transformer is shortened, the transformer life is shortened, etc. It is possible to continue traveling while suppressing the failure of the vehicle.

[2] Second Embodiment FIG. 5 is a process flowchart of a control unit according to the second embodiment.
The second embodiment is different from the first embodiment in that the load on the converter 21 is reduced when there is a margin in the transformer, contrary to the first embodiment.
In parallel with the power conversion operation, the control unit 27 corresponds to the temperature of the transformer 20 corresponding to the transformer temperature detection signal TT output from the first temperature sensor 28 and the converter temperature detection signal TC output from the second temperature sensor 29. The temperature of the converter 21 to be monitored is monitored (step S21).

Next, control unit 27 determines whether or not the temperature of converter 21 is likely to exceed the allowable value (step S22).
In step S22, when the temperature of the converter 21 is unlikely to exceed the allowable value (step S22; No), the control unit 27 shifts the process to step S21 again and enters a standby state. The process will be repeated.

  If it is determined in step S22 that the temperature of the converter 21 is likely to exceed the allowable value (step S22; Yes), the control unit 27 determines whether the temperature of the transformer 20 has a margin, that is, the carrier of the converter 21. It is determined whether or not the converter 21 can be controlled so as to reduce the temperature of the converter 21 by changing the control in the direction of decreasing the load of the converter 21 such as decreasing the frequency or the number of pulses or decreasing the pulse switching frequency. (Step S23).

  If it is determined in step S23 that the temperature of the transformer is likely to exceed an allowable value when the assumed low load control of the converter 21 is performed (step S23; No), the control unit 27 performs the process again. The process proceeds to S21 to enter a standby state, and thereafter the same processing is repeated.

  If it is determined in step S23 that the temperature of the transformer 20 does not exceed the allowable value when shifting to the assumed low load control of the converter 21 (step S23; Yes), the control unit 27 determines that the assumed converter 21 is performed (carrier frequency control, pulse number control, pulse switching frequency control, etc.), and the process is terminated (step S24).

  As described above, according to the second embodiment, when the temperature of the converter 21 is likely to exceed the allowable value and the temperature of the transformer 20 has a margin, the converter 21 is more loaded. By performing low control (control that lowers the load, such as lowering the carrier frequency, lowering the number of pulses, or lowering the pulse switching frequency), it is possible to drive the converter 21 while reducing the load. Therefore, it is possible to continue traveling by suppressing the travel stop state by detecting the overtemperature of the converter 21 or the like.

  In particular, the transformer 20 mounted on the railway vehicle is designed with a margin within the range of commercial operation by rescue of other vehicles (trains), extended power supply, etc., so the control of the second embodiment can be performed. It becomes effective.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 Vehicle control apparatus 15 AC overhead line 16 Pantograph 17 Line 18 Wheel 19 High-speed circuit breaker 20 Transformer 21 Converter 22 Filter capacitor 23 Inverter 24 AC circuit breaker 25 Charging resistor 26 Charge resistance connection contactor 27 Control unit 28 First temperature sensor 29 Second temperature sensor 31H1 Switching element 31H2 Switching element 31L1 Switching element 31L2 Switching element 32H1 Reverse conducting diode 32H2 Reverse conducting diode 32L1 Reverse conducting diode 32L2 Reverse conducting diode M Three-phase AC motor TC Converter temperature detection signal TT Transformer temperature detection signal

Claims (3)

Supplied with AC power from an AC overhead wire, a transformer output as AC power, current and voltage conversion, is input before Symbol the AC power from the transformer, and a converter for performing AC / DC conversion, the output of said converter Is a vehicle control device that performs DC / AC conversion by an inverter and supplies the load to a load,
The As temperature of the transformer does not exceed a predetermined allowable temperature, and the transformer load is to reduce, with a control unit for controlling the operation state before Symbol converter,
Vehicle control device. The control unit controls the operation state of the converter so that the output current on the secondary side of the transformer is closer to a sine waveform.
The vehicle control device according to claim 1 . A transformer which receives supply of AC power from an AC overhead line, performs voltage conversion and outputs as AC power, and a converter which receives the AC power from the transformer and performs AC / DC conversion, and outputs the output of the converter A method executed by a vehicle control device that performs DC / AC conversion by an inverter and supplies the load to a load,
Monitoring the temperature of the transformer and the temperature of the converter;
A process in which temperature of the transformer so as not to exceed a predetermined allowable temperature, and the transformer load is for controlling an operation state of the converter so as to reduce,
With a method.

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