JP2001016701A - Control device for ac electric car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a control device for an AC electric car that prevents deterioration of its performance at the time of occurrence of a failure. SOLUTION: This control device is provided with a converter 4 that converts a first AC voltage Va1 from an AC line 1 into a first DC voltage Vd1, a filter capacitor 5 that filters the first DC voltage to generate a second DC voltage Vd2, an inverter 6 that generates a second AC voltage Va2 of a given frequency from the second DC voltage to supply it to an electric motor 7, a control circuit 11a that controls the converter 4 and inverter 9, and failure detecting circuit 21, 22 that detect the failures of the converter 4 and inverter 9. The control circuits 11a includes failure discriminating means 21, 22 that discriminate which of the converter 4 or inverter 9 failed, and stops the operation of the failed one only in response to the result of the discrimination by the discriminating means 21, 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC electric vehicle control device provided with a converter or inverter failure detection circuit, and more particularly, to control the operation of only one of the converters or the inverter which has failed when a failure occurs in the converter or the inverter. To improve the performance of the AC electric vehicle by continuing the control of the AC electric vehicle.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a conventional control device for an AC electric vehicle disclosed in Japanese Patent Application Laid-Open No. 7-31001. In FIG. 5, an AC overhead line 1 is provided along the track of the electric vehicle, and a pantograph 2 of the AC electric vehicle is in contact with the AC overhead line 1.

The main transformer 3 transforms an AC voltage received from the AC overhead line 1 via the pantograph 2 and takes it into a vehicle-mounted circuit. A pulse width modulation converter (hereinafter, simply referred to as a “converter”) 4 is connected to a secondary winding of the main transformer 3, and is input from the AC overhead line 1 via the pantograph 2 and the main transformer 3. The first AC voltage Va1 is converted into a first DC voltage Vd1.

[0004] The smoothing capacitor 5 forms an intermediate DC circuit, and smoothes the first DC voltage Vd1 to generate a second DC voltage Vd2. The inverter 6 generates a second AC voltage Va2 having a predetermined frequency from the second DC voltage Vd2, and the electric motor 7 is driven by supplying the second AC voltage Va2.

The converter 4 and the inverter 6 have built-in failure detectors 8 and 9, respectively. Each of failure detectors 8 and 9 is formed of, for example, an ammeter or a voltmeter, and has a detection signal D composed of a current value or a voltage value.
1 and D2 are output.

A failure detection circuit 10 detects a failure of converter 4 and inverter 6 based on detection signals D1 and D2 from failure detectors 8 and 9, and outputs a failure detection signal E when a failure occurs.

The control circuit 11 outputs an operation command signal C in response to various operation commands (not shown) and a failure detection signal E, and controls the converter 4 and the inverter 6.

Next, the operation of the conventional control device for an AC electric vehicle shown in FIG. 5 will be described. First, the AC voltage applied to the main transformer 3 from the AC overhead line 1 via the pantograph 2 is stepped down through the secondary winding of the transformer 3 and is input to the converter 4 as the first AC voltage Va1. .

The converter 4 performs a pulse width modulation control on the first AC voltage Va1 to output the first DC voltage Vd1 while keeping the power factor substantially at 1, and converts the first DC voltage Vd1. Control to a constant value.

[0010] The smoothing capacitor 5 connected to the output side of the first DC voltage Vd1 functions as a DC voltage source for generating the second DC voltage Va2. The inverter 6 controls the variable voltage variable frequency (VV) based on the second DC voltage Va2.
VF) to output a second AC voltage Va2 to drive and control the electric motor 7.

On the other hand, failure detectors 8 and 9 housed in converter 4 and inverter 6 input detection signals D1 and D2 such as the current value or voltage value of converter 4 or inverter 6 to failure detection circuit 10.

When the detection signals D1 and D2 indicate abnormal values, the failure detection circuit 10 considers that a failure has occurred and inputs a failure detection signal E to the control circuit 11. Control circuit 11 immediately turns off operation command signal C for converter 4 and inverter 6 in response to failure detection signal E, and stops the operation of the control device for the AC electric vehicle.

At this time, even if only one of the converter 4 and the inverter 6 fails, the operation of both the converter 4 and the inverter 6 is stopped by turning off the operation command signal C. The operation is stopped.

Therefore, when a plurality of control devices are mounted on a single train train, the vehicle performance is degraded due to the complete stoppage of one control device.
When an electric train is operated only by one control device, the train itself becomes inoperable.

As shown in, for example, JP-A-8-50703, an AC electric car of one train is shown in FIG.
By installing a plurality of control devices having the same configuration as above and providing a phase difference (in the case of two, a phase difference of １ ／ of the wavelength λ of the harmonic) in the pulse width modulation control for each converter 4 Also, a technique has been proposed in which harmonics generated from each converter 4 are canceled by the entire train to suppress the influence on the AC voltage on the AC overhead line 1.

However, in such a device for canceling harmonics, if one of the plurality of control devices stops operating, harmonics generated from the entire train cannot be canceled, and harmonics are greatly reduced. To adversely affect the AC voltage on the AC overhead line 1.

Further, in order to cancel harmonics when one of the control devices fails, the phase difference of the pulse width modulation control set for each converter 4 in the remaining control devices is determined by:
It will be necessary to set again.

[0018]

As described above, a conventional AC electric vehicle control device is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-31001.
In the case of the device described in the official gazette, even if only one of the converter 4 and the inverter 6 fails, the operation of both the converter 4 and the inverter 6 is stopped. However, there was a problem that it became inoperable.

In a case where harmonics generated by a plurality of control devices are cancelled, as in a device described in Japanese Patent Application Laid-Open No. 50703/1996, the operation of one control device There has been a problem that harmonics generated from the entire train at the time of stoppage are greatly increased, which adversely affects the AC voltage on the AC overhead line 1.

Further, in order to restore the function of canceling the harmonics, there is a problem that it is necessary to reset the phase difference of the pulse width modulation control of another converter 4 which has not stopped due to a failure.

The present invention has been made in order to solve the above-mentioned problems, and when a failure occurs in a converter or an inverter, only one of the failed units is stopped and the other is operated, thereby reducing the performance. It is an object of the present invention to obtain a control device for an AC electric vehicle that can prevent the electric vehicle.

Further, in the case of a device having a plurality of control devices mounted thereon for canceling harmonics, even if the inverter in one control device fails, the converter in the failure control device is operated. By maintaining the harmonic cancellation function,
An object of the present invention is to provide a control device for an AC electric vehicle that can suppress an increase in harmonics.

[0023]

According to a first aspect of the present invention, a control apparatus for an AC electric vehicle converts a first AC voltage input from an AC overhead line via a main transformer into a first DC voltage. A converter that smoothes the first DC voltage to generate a second DC voltage, an inverter that generates a second AC voltage having a predetermined frequency from the second DC voltage and supplies the second AC voltage to the electric motor, A control circuit that controls the converter and the inverter; and a failure detection circuit that detects a failure of at least one of the converter and the inverter and outputs a failure detection signal. A failure determining means for determining which of the inverter and the inverter has failed, and responding to the determination result of the failure determining means, The operation of the one when taken alone is intended to stop.

According to a second aspect of the present invention, there is provided a control device for an AC electric vehicle.
It is composed of a plurality of circuits individually corresponding to the converter and the inverter, and the failure determination means in the control circuit responds to individual failure detection signals from the plurality of failure detection circuits,
This is to determine the occurrence of a failure in either the converter or the inverter.

According to a third aspect of the present invention, in the control apparatus for an AC electric vehicle, the converter according to the first aspect includes a self-extinguishing element and a diode connected in anti-parallel to the self-extinguishing element. Including a plurality of element pairs combined, the control circuit stops the pulse width modulation operation of the self-extinguishing element in the converter when the failure of the converter is determined, and causes the converter to function as a diode rectifier. Things.

According to a fourth aspect of the present invention, there is provided a control apparatus for an AC electric vehicle, wherein the converter, the inverter, the control circuit, and the failure detecting circuit are arranged in parallel with the AC electric vehicle constituting one train. The control circuit includes a plurality of systems mounted, and when the failure of at least one of the inverters in the plurality of systems is determined, the control circuit stops the inverter in which the failure is determined and connects to the inverter in which the failure is determined. By performing a predetermined pulse width modulation operation on the converted converter and canceling out the harmonics individually generated from a plurality of systems, the harmonic generation amount on the AC overhead line side is maintained at the same level as in the normal operation.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention.
In the figure, the same components as those described above (see FIG. 5) are denoted by the same reference numerals, and detailed description thereof is omitted. The control circuit 11A corresponds to the control circuit 11 described above.

In this case, separate fault detection circuits 21 and 22 are provided corresponding to converter 4 and inverter 6, respectively.

Fault detection circuit 2 connected to converter 4
1 detects a failure of only the converter 4 based on the detection signal D1 from the failure detector 8, and outputs a failure detection signal E1 when the failure of the converter 4 occurs.

Failure detection circuit 2 connected to inverter 6
2 detects a failure of only the inverter 6 based on the detection signal D2 from the failure detector 9, and outputs a failure detection signal E2 when a failure occurs in the inverter 6.

When a failure is detected by the failure detection circuits 21 and 22, the control circuit 11A outputs a failure detection signal E.
1 and E2, a failure determining means for determining which of the converter 4 and the inverter 6 has failed.

The control circuit 11A provides the failure detection signals E1, E
The operation command signals C1 and C2 are turned off in response to the result of the determination by the failure determination means based on No. 2, and only the operation of one of the failed circuits is stopped.

That is, since the failure detection signal E1 for the converter 4 and the failure detection signal E2 for the inverter 6 are separately input to the control circuit 11A, the non-faulty converter 4 is controlled in accordance with each failure detection signal E1 or E2. Alternatively, the operation command signal C1 or C2 is separated and output so that only the inverter 6 can operate.

For example, when a failure detection signal E1 indicating a failure of converter 4 is input, control circuit 11A outputs only operation command signal C2 to inverter 6, and a failure detection signal E2 indicating a failure of inverter 6 is provided. Is input, the operation command signal C for the converter 4 is input.
Output only 1

FIG. 2 is a circuit diagram showing a basic configuration example of converter 4 in FIG. Generally, the converter 4 that performs the pulse width modulation operation is configured by a rectifying bridge circuit having a semiconductor switching element as shown in FIG.

That is, the rectifying bridge circuit in the converter 4 includes a plurality of semiconductors combined by a self-extinguishing element 4G such as GTO or IGBT and a diode 4D connected in anti-parallel to the self-extinguishing element 4G. Includes element pairs.

Next, referring to the circuit diagram of FIG.
A specific operation at the time of failure of converter 4 according to the first embodiment of the present invention will be described. First, the converter 4 in the normal state responds to the operation command signal C1 from the control circuit 11A to perform switching control of the self-extinguishing element 4G to perform a boosting operation, so that the DC voltage Vd
1 is controlled to a constant value.

On the other hand, when the failure of converter 4 is detected, control circuit 11A turns off operation command signal C1, and
The control operation of the converter 4 is stopped. At this time, the converter 4 stops the boosting operation, but the diode 4
Since the rectification operation via D is possible, it functions as a diode rectifier.

Therefore, converter 4 can supply DC voltage Vd2 to inverter 6 via smoothing capacitor 5. As a result, when the converter 4 is out of order, although the performance is reduced as much as the DC voltage Vd1 is lower than the predetermined target value, the control operation of the inverter 6 can be continued. Can be.

As described above, the failure of the converter 4 or the inverter 6 is determined, the operation of only the failed circuit is stopped, and the control operation of the sound circuit is continued, so that the minimum operation function is maintained. Thus, a decrease in control function can be suppressed.

Next, with reference to the waveform diagrams of FIGS. 3 and 4, one example of a case where a plurality of control devices of FIG.
The operation when one of the inverters 6 fails will be described. 3 and 4 show input current waveforms at the time of pulse width modulation operation of converter 4 and show respective current waveforms when two control systems including converter 4 and inverter 6 are provided in one train. .

FIG. 3 shows current waveforms when both converters 4 and inverters 6 of the two systems are sound, and FIG. 4 shows that the inverter 6 in the first (No. 1) control circuit of the two systems has failed. It is a current waveform in the case.

In each figure, the input current ia11 of the first converter 4 of the two systems, the input current ia12 of the second converter 4 of the two systems, and the input current ia1 from the AC overhead line 1 of the entire train And each time change is shown in contrast.

As shown in FIG. 3, when converter 4 and inverter 6 are sound, converter 4 in one train set
The modulation operation is performed with a phase difference so as to cancel harmonics. That is, as shown by the broken line, the input current ia11 of the first converter 4 and the input current ia12 of the second converter 4 of the two systems are 1/1 / of the wavelength λ of the harmonic.
It has a phase difference of two so that harmonics cancel each other.

Therefore, the AC voltage on the AC overhead line 1 does not affect the harmonics, and as shown in FIG. 3, the input current ia1 from the AC overhead line 1 has a waveform containing almost no harmonics.

On the other hand, even if the first inverter 6 in the two systems fails, the first converter 4 in the failed system continues the predetermined pulse width modulation operation. That is, as shown in FIG. 4, the input current ia11 of the first converter 4 is
In the no-load state where no load is applied to the inverter 6, the modulation operation is continuously performed on the input current ia12 of the second converter 4 while maintaining the same phase difference (see the broken line) as in FIG. .

At this time, the harmonic current generated from the first converter 4 is hardly affected by the size of the load, but is affected only by the modulation operation frequency of the converter 4. Therefore, by continuing the operation of only the first system converter 4 when the first inverter 6 fails, the input current ia1 (see FIG. 4) on the AC overhead line 1 becomes
The same waveform as in the normal operation (see FIG. 3) is maintained.

As described above, even when one inverter 6 fails and stops when a plurality of systems are operated in parallel, the converter 4
Continuation of the pulse width modulation operation of
The amount of harmonic generation on the side can be maintained equal to that during normal operation before the occurrence of a failure, and adverse effects due to superposition of harmonics on the AC overhead wire 1 can be prevented.

As described above, the failure of the converter 4 or the inverter 6 is determined, the control of only the failed part is stopped, and the other operation is continued, so that a large performance drop and a large increase in harmonics are prevented. And high-performance control can be maintained.

[0050]

As described above, according to the first aspect of the present invention, a converter for converting a first AC voltage input from an AC overhead line via a main transformer into a first DC voltage,
A smoothing capacitor that smoothes the DC voltage of the second DC voltage to generate a second DC voltage, an inverter that generates a second AC voltage having a predetermined frequency from the second DC voltage and supplies the second AC voltage to the electric motor, and controls the converter and the inverter. A control circuit, and a failure detection circuit that detects a failure of at least one of the converter and the inverter and outputs a failure detection signal. When the failure detection signal is generated, the control circuit detects which of the converter and the inverter has a failure. The failure determination means for determining whether a failure has occurred, and in response to the determination result of the failure determination means, stops the operation of only one of the converter and the inverter in which the failure has occurred. There is an effect that a control device for an AC electric vehicle that can be obtained is obtained.

According to a second aspect of the present invention, in the first aspect, the failure detection circuit is constituted by a plurality of circuits individually corresponding to a converter and an inverter, and the failure determination means in the control circuit is provided by a plurality of failure determination means. In response to an individual failure detection signal from the failure detection circuit of (1), the occurrence of failure of either the converter or the inverter is determined, so that the effect of obtaining an AC electric vehicle control device capable of preventing performance degradation can be obtained. is there.

According to a third aspect of the present invention, in the first aspect, the converter comprises a plurality of elements combined by a self-extinguishing element and a diode connected in anti-parallel to the self-extinguishing element. When a converter failure is determined, the control circuit stops the pulse width modulation operation of the self-extinguishing element in the converter and causes the converter to function as a diode rectifier. In some cases, the inverter can be operated while only the converter is stopped, and there is an effect that a control device for an AC electric vehicle that can prevent a decrease in performance can be obtained.

According to a fourth aspect of the present invention, in the first aspect, the converter, the inverter, the control circuit, and the failure detection circuit are provided by a plurality of systems mounted in parallel on an AC electric vehicle constituting one train. And the control circuit is
When a failure of at least one inverter in the plurality of systems is determined, the inverter whose failure is determined is stopped, and a converter connected to the inverter whose failure is determined is subjected to a predetermined pulse width modulation operation, By canceling harmonics generated individually from a plurality of systems with each other, the amount of harmonics generated on the AC overhead line is maintained at the same level as during normal operation, so even if the inverter in one control device fails, By operating the converter in the failure control device, it is possible to maintain the function of canceling harmonics, and to obtain a control device for an AC electric vehicle capable of suppressing an increase in harmonics.

[Brief description of the drawings]

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

FIG. 2 is a circuit diagram showing a basic configuration example of a converter in FIG.

FIG. 3 is a waveform diagram showing converter input currents and AC overhead wire input currents of a plurality of systems during normal operation according to the first embodiment of the present invention.

FIG. 4 is a waveform chart showing converter input currents and AC overhead wire input currents of a plurality of systems when an inverter failure occurs according to the first embodiment of the present invention.

FIG. 5 is a block diagram showing a conventional control device for an AC electric vehicle.

[Explanation of symbols]

1 AC overhead line, 2 pantograph, 3 main transformer, 4
Converter, 4D diode, 4G self-extinguishing element, 5 smoothing capacitor, 6 inverter, 7 motor,
8, 9 Failure detector, 11A control circuit, 21, 22
Failure detection circuit, C1, C2 operation command signal, E1, E2
Failure detection signal, input current of ia11, ia12 converters, input current of ia1 AC overhead wire, Va1 first AC voltage, Vd1 first DC voltage, Vd2 second DC voltage, Va2 second AC voltage.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02P 7/63 302 H02P 7/63 302S // H02H 7/122 H02H 7/122 Z F term (Reference) 5G053 CA02 DA01 EB01 EB08 FA04 5H007 AA05 AA08 AA17 BB06 CC01 CC03 DA04 DB01 FA12 FA13 GA01 GA08 5H115 PA08 PA14 PC02 PG01 PI02 PU08 PV07 PV09 PV23 PV28 RB22 TO12 TO13 TR05 TU01 TU04 TW10 TZ04 TZ10 H05 BB10 H05 BB10 H05 BB10 H05 BB10 H05 BB10 LL24 MM01

Claims (4)

[Claims] 1. A converter for converting a first AC voltage input from an AC overhead line via a main transformer into a first DC voltage, and smoothing the first DC voltage to generate a second DC voltage. A smoothing capacitor to be generated, an inverter that generates a second AC voltage having a predetermined frequency from the second DC voltage and supplies the second AC voltage to an electric motor, a control circuit that controls the converter and the inverter, A control device for an AC electric vehicle, comprising: a failure detection circuit that detects at least one failure and outputs a failure detection signal. The control circuit, when the failure detection signal is generated, the converter and the inverter A failure determining means for determining which of the above has caused a failure, and in response to a determination result of the failure determining means, AC electric vehicle control apparatus characterized by stopping the fault occurred only one of the operation of the inverter. 2. The fault detecting circuit includes a plurality of circuits individually corresponding to the converter and the inverter, and the fault determining means in the control circuit detects an individual fault from the plurality of fault detecting circuits. The control device for an AC electric vehicle according to claim 1, wherein a failure occurrence of any of the converter and the inverter is determined in response to a signal. 3. The converter according to claim 1, wherein the converter includes a self-extinguishing element.
The control circuit includes a plurality of element pairs combined by a diode connected in anti-parallel to the self-extinguishing element, and the control circuit, when a failure of the converter is determined, the self-extinguishing type in the converter. The control device for an AC electric vehicle according to claim 1, wherein the pulse width modulation operation of the elements is stopped, and the converter functions as a diode rectifier. 4. The converter and the inverter,
The control circuit and the failure detection circuit are composed of a plurality of systems mounted in parallel on an AC electric vehicle constituting one train, and the control circuit is configured to determine a failure of at least one inverter in the plurality of systems. In this case, the inverter whose failure has been determined is stopped, the converter connected to the inverter whose failure has been determined is subjected to a predetermined pulse width modulation operation, and harmonics individually generated from the plurality of systems are mutually transmitted. The control apparatus for an AC electric vehicle according to claim 1, wherein the harmonic generation amount on the AC overhead line side is maintained equal to that during normal operation by canceling out.