JP2009189198A - Electric vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the capacitance of a discharge resistor and to reduce constraint on installation space due to heating, by performing on/off control with the switch for a discharge circuit under an excessive DC voltage. <P>SOLUTION: As an excessive voltage used by an excessive voltage discharge circuit of an electric vehicle control device, an self-arc-suppressing semiconductor switch is used for on/off control during a period in which such circuit as a current flows in from a trolley wire 1 side is constituted. Thus, a flow-in current is limited to reduce the loss of a discharging resistor 7. Occurrence of Joule heat is suppressed and a constraint on the space for attaching equipment is relaxed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electric vehicle control device having a power regeneration function, and more particularly to a control method when a DC overvoltage is generated.

  FIG. 2 shows a main circuit portion of a conventionally used electric vehicle control apparatus. Electric power is received from the trolley wire 1 through the current collector 2 and converted into three-phase AC power by an electric vehicle control device comprising a circuit breaker 3, a unit switch 4, a DC filter reactor 5, a DC filter capacitor 8, and an inverter circuit 9. The motor 10 is driven to drive the electric vehicle. When the electric vehicle control device applies a brake, it is a well-known technique to regenerate the energy traveled by the electric vehicle and apply the brake.

  However, when the electric vehicle control device tries to regenerate power on the trolley line 1 side, if there is no load that consumes the power in the same feeding section of the trolley line 1, the power regenerated by the inverter circuit 9 is This acts in the direction of increasing the voltage of the DC filter capacitor 8, causing the DC voltage in the electric vehicle control device to be overvoltage and causing the device to break.

  As an example of the protection operation when a DC overvoltage occurs, the regenerative operation by the inverter circuit 9 is stopped and the discharge circuit constituted by the overvoltage switch 6 and the discharge resistor 7 is turned on so that the DC filter capacitor 8 is charged. There is known a control for discharging the generated electric charge and suppressing the voltage.

  In FIG. 2, the overvoltage switch 6 has a configuration example using a thyristor. When the overvoltage switch 6 is ignited, inflow of power occurs not only from the DC filter capacitor 8 side but also from the trolley wire 1 side. Usually, the unit switch 4 is activated simultaneously with the ignition of the overvoltage switch 6. Open and suppress power inflow from the trolley wire 1 side.

Normally, the overvoltage switch 6 is made of a semiconductor in order to perform the protection operation quickly, and the unit switch 4 is constituted by a mechanical contact. Therefore, even if the ignition signal of the overvoltage switch 6 and the opening signal of the unit switch 4 are output simultaneously, the discharge resistor 7 is connected to the discharge resistor 7 from the trolley wire 1 side because the ignition of the overvoltage switch 6 is early due to the difference in the respective operation speeds. A power inflow period occurs.
JP 11-178201 A

  Although the electric power consumed by the discharging resistor 7 is not only the electric charge of the DC filter capacitor 8 but also in a short period of time, the electric power inflow from the trolley wire 1 side occurs, so it is necessary to increase the capacity of the discharging resistor 7. In addition, the peripheral portion is exposed to heat by Joule heat generated from the discharge resistor 7.

  When the capacity of the discharge resistor 7 is increased, the volume is naturally increased. In addition, it is necessary to provide a space around the discharge resistor 7 to avoid the influence of heat, which restricts a limited device mounting space of the electric vehicle.

  According to the invention of claim 1, from the trolley wire through the current collector, the circuit breaker, the unit switch, the DC filter reactor, the DC filter capacitor, the inverter circuit, the discharge switch by the self-extinguishing semiconductor, the discharge resistor In the electric vehicle control device configured to be capable of discharging the DC filter capacitor in the discharge circuit, until the unit switch can be opened in order to eliminate power inflow from the trolley line side when a DC overvoltage is generated, It is characterized in that the occurrence of loss in the discharge resistor is reduced by controlling on / off of a discharge switch using a self-extinguishing type semiconductor and suppressing power inflow from the trolley wire side.

  That is, the self-extinguishing semiconductor switch 11 having a self-extinguishing capability with respect to the overvoltage switch 6 in FIG. 2 is used until the unit switch 4 is opened when the overvoltage protection operation occurs. Perform on / off control.

  By performing the on / off control, the current flowing from the trolley wire 1 to the discharging resistor 7 during the overvoltage protection operation period is suppressed, and the loss of the discharging resistor 7 is reduced, so that the capacity of the discharging resistor 7 itself is reduced. In addition, the generation of Joule heat can be suppressed and the restriction on the equipment mounting space can be relaxed. Naturally, since the electric charge of the DC filter capacitor 8 is also discharged, the electric vehicle control device is released from the DC overvoltage state.

  The electric vehicle control device configured to suppress the volume of the discharge resistor 7 and heat generation can be configured with the same number of parts as in the past.

  FIG. 1 shows an embodiment of the apparatus of the present invention. Except for the self-extinguishing semiconductor switch 11, the configuration is the same as in FIG. In the example of FIG. 1, the self-extinguishing semiconductor switch 11 is described with the IGBT symbol, but other self-extinguishing semiconductors can also be configured.

  The operation of the electric vehicle control device configured in FIG. 1 will be described. When the inverter circuit 9 starts the regenerative operation, if there is no load that consumes the regenerative power in the same power supply section of the trolley wire 1 connected to the electric vehicle control device, the DC filter capacitor 8 is charged and the DC overvoltage state is reached. It becomes. When the DC overvoltage state is reached, the protection of the electric vehicle control device is activated, the regenerative operation of the inverter circuit 9 is stopped, the self-extinguishing semiconductor switch 11 is ignited, and a signal for opening the unit switch 4 is transmitted.

  Since the self-extinguishing semiconductor switch 11 is ignited, a part of the electric charge of the DC filter capacitor 8 is discharged through the discharging resistor 7 and is thus released from the DC overvoltage state. The self-extinguishing semiconductor switch 11 performs on / off control until the unit switch 4 is in an open state, and the current flowing through the self-extinguishing semiconductor switch 11 is in an intermittent state. The discharge current from the filter capacitor 8 does not increase rapidly.

When the unit switch 4 is in the open state, the self-extinguishing semiconductor switch 11 is shifted to the continuous conduction state, the discharge from the DC filter capacitor 8 is promptly performed, and the electric vehicle control device can be operated safely. Make the voltage as high as possible.
It can be easily detected by the auxiliary contact that the unit switch 4 is opened.

  When the on / off control of the self-extinguishing type semiconductor switch 11 is accompanied by an increase in the loss of the self-extinguishing type semiconductor switch 11 itself, the period during which the on / off control is performed is until the unit switch 4 is in an open state. The cooler used in the semiconductor switch 11 can be configured as small as a mounting structure.

  By using a self-extinguishing semiconductor switch as a semiconductor switch used in the discharge circuit at the time of DC overvoltage and performing on / off control for a predetermined period, the current flowing from the trolley wire to the discharge resistor is suppressed, and the discharge resistor An electric vehicle control device having a small volume and suppressing heat generation can be configured.

An example of an electric vehicle control device according to the present invention. The example of the conventional electric vehicle control apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Trolley wire 2 Current collector 3 Circuit breaker 4 Unit switch 5 DC filter reactor 6 Overvoltage switch 7 Discharge resistor 8 DC filter capacitor 9 Inverter circuit 10 Motor 11 Self-extinguishing semiconductor switch

Claims (1)

The DC filter capacitor in a discharge circuit comprising a circuit breaker, a unit switch, a DC filter reactor, a DC filter capacitor, an inverter circuit, a discharge switch using a self-extinguishing semiconductor, and a discharge resistor from a trolley wire through a current collector In the electric vehicle control device configured to be capable of discharging, a self-extinguishing semiconductor discharge switch until the unit switch can be opened in order to eliminate power inflow from the trolley line when a DC overvoltage occurs The electric vehicle control device is characterized in that the occurrence of loss in the discharging resistor is reduced by controlling on / off of the power supply and suppressing the inflow of electric power from the trolley line side.

Images