JP2002159104A - Controller for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric vehicle with a plurality of power converters capable of generating maximum output all the time without depending on its open condition even if any of the power converters is opened. SOLUTION: This controller for electric vehicle is provided with a plurality of power converters 7a-7d which convert DC power into AC power of variable voltage and variable frequency and supply the AC power to a plurality of motors 8a-8d respectively. Further, the controller includes current sensors 9a-9d for detecting the input current of the respective power converters, a transmission channel 12 for transmitting an input current detecting value between the respective power converters mutually, a reference current setting part 16 for setting a reference current value, a maximum current computing part 15 for computing the maximum current running through the controller from the input current detecting value of the respective power converters, and a torque command computing part 17 for obtaining a deviation between the maximum input current and the reference current and computing the torque current command of its power converter for outputting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electric vehicle having a plurality of main power converters, each of which converts DC power into AC power and supplies the AC power to a motor for driving the electric vehicle.

[0002]

2. Description of the Related Art Conventionally, a control device for an electric vehicle as shown in FIG. 10 is known. The control device of this conventional electric car is:
In order to supply electric power to each of a plurality of electric motors (IM) 8a to 8d for driving an electric vehicle, PWM inverters 7a to 7 are used as power converters for converting DC power to AC power.
It has a main circuit configuration utilizing d. In this conventional electric vehicle control device, a DC voltage output from a substation 10 is collected through an overhead line 11 and a pantograph 1, and the collected DC power is input to and output from the high-speed circuit breakers 2a and 2b. A PWM inverter as a power converter for converting into AC power of a variable voltage and variable frequency via current breakers 3a to 3d that also open the output and the converter, charging resistors 4a and 4b, and filter reactors 5a to 5d. After that, VVVF
(Referred to as inverters) 7a to 7d.

The VVVF inverters 7a to 7d use a self-extinguishing type semiconductor switching element, for example, a GTO thyristor or an IGBT. The semiconductor switching element forms a three-phase bridge circuit and conducts at an arbitrary timing. A three-phase induction motor (IM) for controlling a non-conducting state, converting DC power to AC power, and driving an electric vehicle
8a to 8d are driven.

The VVVF inverters 7a to 7d are provided with control units 6a to 6d, respectively. The control units 6a to 6d output a powering operation command and a regenerative braking operation output from a command unit such as a mascon of a cab. Command and torque command and receive the VVVF inverter 7a.
To 7d. Each of these control units 6a-
6d obtains a torque current command for controlling each of the induction motors 8a to 8d, and controls the torque of each of the induction motors 8a to 8d.

[0005] In the case of electric vehicles, the DC power output from the substation is determined by the route, and is designed not to exceed the power. However, in electric vehicles such as electric locomotives that pull freight cars, the route of travel is not determined, and the maximum rating of VVVF inverters and induction motors is higher than that of ordinary trains so that a large amount of cargo can be carried at once. Due to the large capacity, some routes may exceed the power capacity of the substation. Therefore, it is necessary to control not to exceed the maximum power according to the substation conditions for each line, but conversely, to pull many vehicles such as wagons and run on slopes, strong traction force Requires
It is necessary to always be able to output the maximum allowable output of the substation.

On the other hand, at the time of regenerative braking, it is necessary to keep the regenerative brake balance between converters as constant as possible. However, if the regenerative current is started indefinitely, the voltage becomes too high, and exceeds the withstand voltage of the switching element. Therefore, in order to avoid this, usually, a limiter pattern for controlling the regenerative current according to the filter capacitor voltage is prepared, and the control is performed so that the regenerative torque command is reduced as the filter capacitor voltage increases.

[0007]

However, such a conventional electric vehicle control device has the following problems. Until now, the maximum power determined according to the running section has been equally divided from the maximum output of the plurality of VVVF inverters, and the torque limit has been set. For this reason, the torque command calculated from the equally divided maximum output is determined irrespective of the state of the other VVVF inverters. However, since it is necessary to limit the total output of the plurality of VVVF inverters, for example, even if the torque command of one VVVF inverter detects idling and reduces the torque current, the other The VVVF inverter is limited to equally divided torque commands and cannot output the maximum torque.

[0008] Further, during the regenerative braking operation, the torque current is calculated for each converter in order to control the torque current by the filter capacitor voltage. For this reason, a current imbalance occurs between the converters due to disturbance conditions or sensor detection, and the sharing of regeneration may not be uniform.
However, in order to compensate for the lack of regenerative braking force with air braking force, if the regenerative braking force is balanced in a small state, the load on the air brake increases, and the frequency of use of the brake shoe to apply the air brake increases,
As a result, the replacement time of frequently used brake shoes is advanced, which is not preferable in terms of vehicle maintenance.

The present invention has been made to solve such a conventional technical problem, and provides an electric vehicle control device that enables a plurality of power converters to always output a maximum output. The purpose is to:

[0010]

According to the first aspect of the present invention, there is provided an electric vehicle having a plurality of power converters for converting DC power into AC power having a variable voltage and a variable frequency and supplying the AC power to each of a plurality of motors. In the control device, a current sensor for detecting an input current of each of the plurality of power converters, and a transmission for mutually transmitting an input current detection value detected by each of the current sensors to each of the plurality of power converters Means, a reference current setting means for setting a reference current value, and a maximum current calculation for calculating a maximum current value flowing through the apparatus from input current detection values of each of the plurality of power converters received via the transmission means. Means for calculating a deviation between the maximum current calculated by the maximum current calculation means and the reference current value set by the reference current setting means, and obtaining a torque current command for its own power converter. It is obtained by a torque current calculator for calculating and outputting.

[0011] In the electric vehicle control device according to the first aspect of the present invention,
Instantly finds the total input current of multiple power converters, corrects the input current of each power converter by comparing it with the maximum current according to the reference route, and can always ensure the maximum power output . Also, when multiple power converters are opened,
Since the sum of the input currents is obtained, each power converter can be controlled to the torque current of the maximum power regardless of the number of open currents.

According to a second aspect of the present invention, in the electric vehicle control device according to the first aspect, a reference current value set by the reference current setting means is set according to a position of a motor driven by each of the power converters. The present invention is characterized in that a current set value correcting means for increasing / decreasing correction is provided.

[0013] According to a second aspect of the present invention, there is provided a control apparatus for an electric vehicle.
The state of the track and the wheels changes according to the wheel arrangement conditions such as the axis of the traveling direction and the leading axis, but it is suitable for the track and vehicle conditions by correcting the reference current command according to the wheel arrangement conditions. The torque current command can be obtained, and the control can be performed with the torque current of the maximum power.

According to a third aspect of the present invention, in the control device for an electric vehicle according to the first or second aspect, the input current detection value detected by the current sensor and the input current detection of each of the other power converters received by the transmission means are provided. A reference input current calculating means for calculating a reference input current of the power converter from the reference value, and a regenerative current command for correcting a regenerative current command between the power converters from a deviation between the input current detection value and the reference input current value. It is characterized by comprising a correcting means.

According to a third aspect of the present invention, there is provided the electric vehicle control device,
Corrects the imbalance of the regenerative braking force between the power converters and the imbalance of the regenerative limiter control due to the deviation of the filter capacitor voltage, makes the regenerative braking force even, and equalizes the electric brake and air brake sharing on each axis. Thus, wear of the brake shoes can be averaged.

According to a fourth aspect of the present invention, in the control device for an electric vehicle according to the third aspect, the position of the electric motor driven by each of the power converters is determined with respect to the reference input current value calculated by the reference current calculation means. And a regenerative brake current setting means for setting the regenerative brake current command accordingly.

According to a fourth aspect of the present invention, there is provided the electric vehicle control device,
The filter capacitor voltage due to regenerative braking changes according to the wheel placement conditions, such as the traveling axis and the leading axis,
By correcting the reference current command according to the arrangement condition, a torque current command suitable for the vehicle condition can be obtained, and the regenerative braking force is shared with the air brake so as to be suitable for the vehicle condition. And the wear of the brake shoes can be reduced.

According to a fifth aspect of the present invention, in the electric vehicle control device of the first aspect, a brake chopper circuit comprising a resistor and a semiconductor switching element is connected in parallel with each of the plurality of power converters. A current sensor and control means for instructing a flow rate to a brake chopper and a gate operation in accordance with a state of an input current from input current detection means of each of the plurality of power converters. .

According to a fifth aspect of the present invention, there is provided the electric vehicle control device,
If the regenerative braking force is low during the operation of the brake chopper, if the overhead line voltage rises above the filter capacitor voltage, current will flow from the substation and power will be consumed regardless of the brake mode. However, by instructing the operation of the brake chopper, it is possible to prevent the flow from the substation at the time of braking.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a configuration of a control device for an electric vehicle according to a first embodiment of the present invention. The electric vehicle control device shown in FIG. 1 is different from the conventional circuit configuration shown in FIG. 10 in that an input current detection sensor 9a for detecting the input current of each of a plurality of VVVF inverters 7a to 7d.
To 9d, and a detection current signal is input from each input current detection sensor to each of the control units 6a to 6d.
The control units 6a to 6d for controlling the respective VVVF inverters 7a to 7d are connected by a transmission line 12 so that each control unit can receive the input current detection value of each VVVF inverter from another control unit. There are features. Other components are shown in FIG.
Elements common to those of the conventional circuit shown in FIG. 0 are denoted by the same reference numerals.

FIG. 2 shows each control unit 6a in FIG.
6 to 6d show the internal configuration. In the following description, the control unit 6a will be described as a representative.
The same applies to the other control units 6b to 6d. The control unit 6a receives a current detection signal from an input current detection sensor 9a that monitors the input current of the VVVF inverter 7a to obtain an input current value, and an input current detection unit 13 that obtains an input current value. 6b to 6d, a transmission signal setting unit 14 for transmitting through the transmission path 12,
The input current detection value IS1 output from the input current detection unit 13 of the own device and the other control units 6b to
6d, the maximum input current calculation unit 15 for calculating the maximum input current to the apparatus by summing the input current detection values IS2 to IS4, and the reference current setting unit 1 for setting the route reference current
6. The maximum input current calculated by the maximum input current calculation unit 15 and the reference current set value ISre set by the reference current setting unit 16
A current command / torque command control unit 17 that calculates and outputs a torque command for a deviation from f is provided. The signal from the current command / torque command control unit 17 is the VVVF of the own device.
A drive signal for the inverter 7a.

Next, the operation of the electric vehicle control device according to the first embodiment having the above configuration will be described. Multiple VVs
In the VF inverters 7a to 7d, an input current detection sensor 9a for detecting a DC input current of the VVVF inverter
-9d are mutually transmitted and received between the VVVF inverters 7a-7d through the transmission line 12, so that one VVVF inverter 7a
Control unit 6a detects the input current of the entire apparatus.

In the control unit 6a shown in FIG.
The input current of the F inverter 7a is detected by the input current sensor 9a, and based on the detection signal, the input current detection unit 13 obtains the input current detection value IS1 and inputs it to the transmission signal setting unit 14. The transmission signal setting unit 14 updates the input current detection value IS1 to the own inverter 7a and transmits this to the other control units 6b to 6d via the transmission line 12. In each of the control units 6b to 6d, in the transmission signal setting unit 14, the Vs received from the control unit 6a is
The input current value IS1 to the VVF inverter 7a is updated.

In the maximum input current calculation section 15, each V
The input current of the entire device is always detected by summing the input current detection values of the entire VVF inverters 7a to 7d.

The route reference current setting section 16 sets a reference current value of the route. In the current designation / torque command control unit 17, based on the deviation between the input current of the entire apparatus obtained by the maximum input current calculation unit 15 and the route reference current value ISref set by the reference current setting unit 16, this deviation is negative. When the value becomes a value, the torque current command is reduced to control the input current.

Thus, the plurality of VVVF inverters 7
If any one of the devices a to 7d fails and is opened, the current set value ISref is normally changed from the open information. However, in the present embodiment, control is always performed based on the maximum current. This eliminates the need to control the open state. Also,
According to the present embodiment, regardless of the opening condition of the inverter, and even if another group of inverters continues to reduce the current command due to disturbance such as idling, the maximum output of the entire device is always output. Can be controlled.

Next, a control device for an electric vehicle according to a second embodiment of the present invention will be described with reference to FIGS. The overall configuration of the electric vehicle control device according to the second embodiment is shown in FIG.
Are common to the first embodiment shown in FIG. The feature of the present embodiment lies in the internal configuration of each of the control units 6a to 6d, which is the configuration shown in FIG. This will be described below.

FIG. 3 shows the internal configuration of the control unit 6a as a representative, but the same applies to the other control units 6b to 6d. In the case of the second embodiment, the control unit 6a is configured to further correct the reference current value of the reference current setting unit 16 with respect to the configuration of the control unit 6a in the first embodiment shown in FIG. It is characterized by including a current set value correction unit 21. The other components are common to those of the first embodiment shown in FIG.

As shown in FIG. 4, if wheels 110a to 110d are arranged before and after the electric vehicle 100 and each is driven by induction motors 8a to 8d, for example, when the traveling direction is F, the same torque is applied. Each wheel 110a-1
When applied to 10d, one-axis and three-axis wheels 110a, 110
c, a large torque is applied, and conversely, a two-axis, four-axis wheel 11
The torque is hardly applied to 0b and 110d.

Therefore, in the present embodiment, if the traveling direction is F and the axle is one axis and three axes, the torque is set by the current set value correction section 21 based on the traveling direction signal and the axle number signal controlled by the self. By increasing the command from the normal value, and conversely, if the axle has two axes and four axes, the reference current value is corrected so as to reduce the torque command from the normal value.
A driving force is evenly generated in 10a to 110d. For example, in the case of the control unit 6a, the one-axis wheel 110a
, Which controls the VVVF inverter 7a that supplies electric power to the motor 8a that drives the inverters 7a to 7d. 110d
The output according to the position is effectively used as the whole apparatus. When the traveling direction becomes the R direction, the control of the first axis, the third axis, the second axis, and the fourth axis is reversed.

Also, depending on the route, the maximum current may change depending on the current conditions of the substation. In this case as well, setting according to the route information is possible, and the substation current conditions are recognized by inputting a signal from a monitor or a point signal from the monitor to the current set value correction unit 21 to automatically set the reference current value. Is corrected, it is not necessary for the crew to manually set.

Next, a control device for an electric vehicle according to a third embodiment of the present invention will be described with reference to FIGS. The feature of the third embodiment is that the input currents of the VVVF inverters 7a to 7d detected by the input current detection sensors 9a to 9d are mutually transmitted to the respective control units 6a to 6d via the transmission line 12, and the regeneration is performed. In the mode, the imbalance of the regenerative current between the plurality of inverters is automatically corrected. FIG. 5 shows an internal configuration for the regeneration mode operation in the control unit 6a. That is, V
A detection signal from an input current detection sensor 9a that detects an input current to the VVF inverter 7a is input to obtain an input current detection value IS1, and the input current detection unit 13 determines the input current detection value IS1 for the inverter 7a controlled by itself. , A transmission signal setting unit 14, a reference current detection unit 18,
A regenerative limiter corrector 23 and a current command / torque command controller 17 for controlling regenerative current based on a command from the regenerative limiter corrector 23 are provided.

The reference current detecting section 18 is provided with the transmission signal setting section 1
4 other control unit 6 received through transmission line 12
The average of the input current detection values IS2 to IS4 of the VVVF inverters 7b to 7d from b to 6d and the input current detection value IS1 for the VVVF inverter 7a is obtained, and this is output as a reference current ISref.

The regenerative limiter correction section 23 detects the input current detection value IS1 for its own inverter 7a and the reference current IS
The regenerative torque current with respect to the filter capacitor voltage with respect to the VVVF inverter 7a is changed from the deviation from ref to control the reference input current.

In the control device for an electric vehicle according to the third embodiment, the input current IS1
Is larger than the reference current ISref, the current command or the torque command is reduced according to the filter capacitor voltage as shown by the line A → B in FIG. vice versa,
When the input current IS1 is smaller than the reference current ISref, a current command or a torque command is increased as shown by a line A → C in FIG. This allows
Correct the unbalance of the regenerative braking force between inverters and the imbalance of the regenerative limiter control due to the detection error of the filter capacitor voltage, equalize the regenerative power and equalize the electric brake and air brake in each axle. To even out the wear of the brake shoes.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 7 shows an internal configuration of a control unit 6a according to the fourth embodiment. The control unit 6a in this embodiment is similar to the control unit 6a in the third embodiment shown in FIG. 5, and includes an input current detection unit 13, a transmission signal setting unit 14, a regeneration limiter correction unit 23, and a current command / torque. A command control unit 17 is provided, and a reference current correction unit 18 ′ is provided instead of the reference current detection unit 18.

The reference current correction section 18 'is connected to the input current IS1 of its own VVVF inverter 7a input from the input current detection section 13 and the transmission signal setting section 14 in the same manner as in the third embodiment. Other control units 6b to 6d
The reference current ISref is obtained by averaging the input currents IS2 to IS4 of the other VVVF inverters 7b to 7d obtained from the above.
f is corrected and output as IS'ref.

The regenerative control by the control device for an electric vehicle according to the fourth embodiment will be described. As shown in FIG. 8, the load on the axle varies depending on the traveling direction of the vehicle 100 and the position of the axle. For this reason, the reference current correction unit 18 'corrects the reference current ISref according to which of the one to four axes the motor 7a drives by the inverter 7a controlled by the own control unit 6a.
Output as IS'ref. For example, when the traveling direction is F and one axis is the leading axle, and the VVVF inverter 7a controlled by the control unit 6a controls the one-axis electric motor 8a, if the road surface condition is poor, it is easy to glide. Therefore, control is performed to reduce the torque current so that the VVVF inverter 7a does not slide. For this reason, the reference current IS'r of the inverter 7a of the leading axle
The correction ef is set to be lower than the normal reference current ISref. Then, the reference current correction unit 18 'of the control units 6b to 6d performs correction for increasing the set value in the order of 2 axes → 4 axes. When the traveling direction is R, the reverse control is performed.

By reducing the torque of the leading axle in this way, it is possible to reduce the chances of running in a gliding state, and as a result, it is possible to increase the ratio of the regenerative braking load even when the road surface condition is poor.

Next, a fifth embodiment of the present invention will be described with reference to FIG. A feature of the fifth embodiment is that a brake chopper device 24 composed of a resistor and a semiconductor switching element is connected in parallel to each of a plurality of VVVF inverters 7a to 7d, and is connected to each of the control units 6a to 6d. The point is that a brake chopper command unit 25 is provided.

The brake chopper command section 25 is provided with the input current detection value IS1 of its own VVVF inverter 7a output from the input current detection section 13 similar to that of the third embodiment shown in FIG. The determined reference current ISre
Based on the deviation from f, the flow rate to the brake chopper device 24 and the gate operation are controlled.

When the brake chopper is operating by the brake chopper device 24, if the regenerative braking force is weak, the overhead wire voltage may be higher than the filter capacitor voltage. In that case, current flows from the substation, and powering power is consumed even in the brake mode.

Therefore, in the case of the fifth embodiment, the input current detection unit 13 of each of the control units 6a to 6d monitors the input current of each of the VVVF inverters 7a to 7d. When it flows, a command to stop the brake chopper operation and perform only the regenerative braking operation is output from the brake chopper command unit 25 to the brake chopper device 24 to prevent the current from flowing from the substation during braking.

[0044]

According to the first aspect of the present invention, the total of the input currents of the plurality of power converters is instantaneously obtained, and the sum of the input currents is compared with the maximum current corresponding to the reference route to determine the input current of each power converter. It is possible to compensate and always keep the maximum power output. In addition, even when a plurality of power converters are opened, the total input current is determined, so that each power converter can be controlled to the maximum power torque current regardless of the number of open converters.

According to the second aspect of the present invention, the state of the track and the wheels changes according to the wheel arrangement conditions such as the traveling direction and the leading axis, but the reference current command is corrected according to the wheel arrangement conditions. Therefore, a torque current command suitable for track and vehicle conditions can be obtained, and control can be performed with a torque current of the maximum power.

According to the third aspect of the present invention, the imbalance of the regenerative braking force between the power converters and the imbalance of the regenerative limiter control due to the deviation of the filter capacitor voltage are corrected, and the sharing of the regenerative braking force is made uniform. The sharing of the electric and pneumatic brakes on the shaft can be equalized and the wear of the brake shoes can be averaged.

According to the fourth aspect of the present invention, the filter capacitor voltage due to the regenerative braking changes according to the wheel arrangement conditions such as the traveling direction and the leading axis, but the reference current command is corrected according to the arrangement conditions. Therefore, a torque current command suitable for the vehicle condition can be obtained, and the regenerative braking force is shared with the air brake so as to be suitable for the vehicle condition, so that the regenerative rate can be increased and the wear of the brake shoes can be reduced.

According to the invention of claim 5, when the regenerative braking force is weak during the operation of the brake chopper, current flows from the substation even when the overhead wire voltage rises from the filter capacitor voltage, and the power running is performed in spite of the brake mode. Although the power is consumed, the input current is monitored to instruct the operation and stop of the brake chopper, so that the current can be prevented from flowing from the substation at the time of braking.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control unit according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of a control unit according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing torque control according to the second embodiment.

FIG. 5 is a block diagram showing a configuration of a control unit according to a third embodiment of the present invention.

FIG. 6 is an explanatory diagram showing regenerative control according to the third embodiment.

FIG. 7 is a block diagram showing a configuration of a control unit according to a fourth embodiment of the present invention.

FIG. 8 is an explanatory diagram showing regenerative control according to the fourth embodiment.

FIG. 9 is a block diagram showing a configuration of a control unit according to a fifth embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of a conventional example.

[Explanation of symbols]

 Reference Signs List 1 Pantograph 6a to 6d Control unit 7a to 7d VVVF inverter 8a to 8d Induction motor 9a to 9d Input current detection sensor 10 Substation 11 Overhead wire 12 Transmission line 13 Input current detection unit 14 Transmission signal setting unit 15 Maximum input current calculation unit 16 Reference Current setting unit 17 Current command / torque command control unit 18 Reference current detection unit 18 'Reference current correction unit 21 Current set value correction unit 23 Regenerative limiter correction unit 24 Brake chopper device 25 Brake chopper command unit

Continued on the front page F term (reference) 5H115 PG01 PI01 PU01 QI04 QN09 RB11 RB22 RB25 SJ13 5H572 AA01 BB07 CC01 DD03 EE04 FF05 FF09 GG04 HA01 HA02 HA07 HB02 HB08 HB09 HC01 HC04 HC07 JJ25 JJ26 JJ28 LL22 DD02 DD02 EE09 EE11 FF04 FF10 GG04 HA01 HB02 JJ25 JJ26 JJ28 LL22 LL60 MM02

Claims (5)

[Claims] 1. An electric vehicle control apparatus comprising: a plurality of power converters for converting DC power into AC power having a variable voltage and a variable frequency and supplying the AC power to each of a plurality of electric motors, wherein the plurality of power converters A current sensor for detecting each input current; transmission means for mutually transmitting the detected input current value detected by each of the current sensors to each of the plurality of power converters; a reference current for setting a reference current value Setting means, maximum current calculating means for calculating a maximum current value flowing through the device from input current detection values of the plurality of power converters received via the transmission means, and calculation of the maximum current calculating means A deviation between a maximum current and a reference current value set by the reference current setting means is calculated, and a torque current command for calculating and outputting a torque current command of its own power converter is output. The electric vehicle controller comprising a means. 2. The apparatus according to claim 1, further comprising a current set value correction unit for performing increase / decrease correction on a reference current value set by said reference current setting unit in accordance with a position of a motor driven by each of said power converters. The control device for an electric vehicle according to claim 1. 3. A reference input current calculation for calculating a reference input current of the own power converter from an input current detection value detected by the current sensor and an input current detection value of each of the other power converters received by the transmission means. 3. A regenerative current command correcting means for correcting a regenerative current command between power converters based on a deviation between the input current detection value and the reference input current value. Electric car control device. 4. A regenerative brake current setting means for setting the regenerative brake current command according to a position of a motor driven by each of the power converters with respect to the reference input current value calculated by the reference current calculation means. The control device for an electric vehicle according to claim 3, wherein the control device is provided. 5. A brake chopper circuit comprising a resistor and a semiconductor switching element is connected in parallel with each of the plurality of power converters, and input current detecting means for each of the current sensor and the plurality of power converters. 2. The control device for an electric vehicle according to claim 1, further comprising control means for instructing a flow rate to a brake chopper and a gate operation in accordance with a state of an input current.