JP2003333862A - Power-converting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power-converting device of high working ratio by using a plurality of low-voltage inverters that are manufactured as a standardized device. <P>SOLUTION: This power-converting device comprises: a converter 2 that converts AC power to DC power; a plurality of inverters 4 each connected in series to a DC power source and connected in parallel to each other; output transformers 5 each connected to the output side of each inverter 4 via an output breaker 12 and whose secondary sides are connected in series to each other; fuses 11 connected to the input side of the inverters 4; short circuit breakers 13 each connected to short-circuit the primary side of each output transformer; and a failure detecting device 8 that detects failures of the inverters 4. When the failure-detecting device detects a failure of one of the inverters 4, the gate of the failed inverter 4 is blocked and its output breaker 12 is opened so that its short circuit breaker 13 is closed to separate the failed inverter 14. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter for converting a DC voltage into an AC voltage, and more particularly to a high voltage and large capacity power converter in which small capacity inverter devices are connected in parallel.

[0002]

2. Description of the Related Art For the purpose of increasing the capacity and voltage of a power conversion device and improving the output waveform, for example, a power conversion device disclosed in Japanese Patent Laid-Open No. 2000-209870 is known. There is. This power converter supplies three-phase AC power to a plurality of unit inverters through a transformer having a plurality of windings on the secondary side from a three-phase power supply. The unit inverters are divided into three groups, the outputs of the unit inverters of each group are respectively connected in series, one of the groups is connected as a neutral point, and the other is connected to each phase of a three-phase electric motor. As a result, three-phase AC power is supplied to the electric motor.

Further, the above publication discloses a main circuit of a unit inverter, in which electric power from a secondary winding of a transformer is converted into DC electric power by a rectifying circuit and a DC smoothing capacitor, and further by a single-phase inverter circuit. It is converted into electric power with frequency and voltage.

In such a conventional power converter, since the main circuit of the unit inverter is directly connected to the high voltage motor, it has a high voltage specification. Therefore, it was necessary to adopt a unit inverter with a voltage specification according to the purpose of use.

[0005]

As described above, in the conventional large-capacity high-voltage power converter, since the unit inverter has a high-voltage specification, the panel size is inevitably large in order to secure the insulation distance. Since it is necessary to use high voltage components for the main circuit components such as the main circuit element and circuit breaker, there is a problem of economic efficiency. Furthermore, the gate signal must be transmitted by an optical signal for the insulation of the control system. There was a problem that it had to be.

Further, considering cost and installation conditions, it is difficult to make the main circuit redundant. When a failure such as an element damage of the main circuit occurs, the apparatus is stopped and the failed part is replaced. Had to do.

The present invention has been made in view of the above points,
It is an object of the present invention to solve the problems of insulation and cost, and to provide a power conversion device with a high operating rate that does not stop the device even if a failure occurs during operation.

[0008]

In order to achieve the above object, a power converter of the present invention comprises a converter device for converting an alternating current into a direct current and a converter device connected in series and connected in parallel with each other. Multiple inverter devices,
Output transformers connected to the output sides of the respective inverter devices through output breakers, and secondary sides of which are connected in series with each other, and fuses connected to the input sides of the respective inverter devices, A short circuit breaker connected to the primary side of the output transformer so as to short-circuit the primary side of each of the output transformers, and a failure detection device for detecting a failure of each of the inverter devices. When any one of the failure detecting devices detects a failure of the inverter device, the corresponding inverter device is gate-blocked,
By opening the output circuit breaker and closing the short circuit breaker, the defective inverter device is disconnected.

In order to achieve the above object, a power converter of the present invention comprises a converter for converting alternating current to direct current,
A plurality of inverter devices connected in series to the converter device and connected in parallel with each other, and connected to the output sides of the respective inverter devices, and their respective secondary sides via the first circuit breaker. Connected in parallel to each output transformer connected in series, a fuse connected to the input side of each inverter device, and a series circuit formed by the first breaker and the secondary winding of the output transformer. A second circuit breaker,
And a failure detection device for detecting a failure of each of the inverter devices, and when any of the failure detection devices detects a failure of the inverter device, gate blocks the corresponding inverter device, By opening the circuit breaker No. 1 and closing the second circuit breaker, the faulty inverter device is disconnected.

In order to achieve the above object, the power converter of the present invention comprises a converter for converting alternating current to direct current,
A plurality of inverter devices connected in series to the converter device and connected in parallel with each other, and output transformers connected to the output sides of the respective inverter devices and having their respective secondary sides connected in series with each other; A fuse connected to the input side of each of the inverter devices, a semiconductor circuit connected to the output side of each of the inverter devices so as to short-circuit or open the output of the inverter device, and a failure of the inverter device. Each of the failure detecting devices for detecting, when any one of the failure detecting devices detects a failure of the inverter device, gate-block the corresponding inverter device, and further short-circuit or open the semiconductor circuit. Thus, the defective inverter device is disconnected.

As described above, according to the present invention, since a plurality of low-voltage power converters manufactured as standard products are used, not only the problems of insulation and cost are avoided, but also a failure occurs during operation. It is possible to provide a power conversion device that has a high operating rate and that does not stop the device even when the above occurs.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of a power conversion device according to the present invention will be described below with reference to FIG. FIG. 1 is a block diagram of a power conversion device according to the present invention.

The three-phase AC power supply stepped down by the input transformer 1 is converted into a DC power supply by the converter device 2, the DC power supply is converted into an AC output by a plurality of inverter cells 7, and the AC output of the inverter cell 7 is converted into an AC output. The output transformer 5 provided on the output side of the inverter cell 7 is connected in series on the secondary side, and the output is supplied to the electric motor 6. A separately excited converter device is usually used as the converter device 2.

The main circuit of each inverter cell 7 receives a DC power source by the smoothing circuit 3 and is connected via a fuse 11 to an inverter device 4, an inverter output breaker 12 and an output transformer provided on the output side thereof. Primary side short circuit breaker 13
Is equipped with. Further, the inverter cell 7 is provided with a failure detection device 8. The failure detection device 8 is adapted to detect a failure of the inverter cell 7 by detecting an abnormality in the voltage or current of the inverter device 4 and the smoothing circuit 3.

The operation of the power converter of the present invention having the configuration of FIG. 1 will be described below. During normal operation, the inverter output breaker 12 in each inverter cell 7 connected in parallel
Is closed and the output transformer primary side short circuit breaker 13 is open.

When a failure occurs in one inverter cell 7 of the plurality of inverter cells 7, the failure detection circuit 8 of the corresponding inverter cell 7 detects this and the inverter device 4 of the failed inverter cell 7 is detected. The gate signal to the inverter circuit is stopped (hereinafter referred to as a gate block), and the inverter output breaker 12 of the defective inverter cell 7 is opened, and at the same time, the output transformer primary side short circuit breaker 1
By closing the switch 3, the defective inverter cell 7 is disconnected from the entire power conversion device to continue the operation.

When an overcurrent failure occurs in the inverter device 4 of the defective inverter cell 7 or its output side, the defective inverter cell 7 is completely disconnected from the device by blowing the fuse 11, and the power source side is disconnected. To prevent the inflow of abnormal current.

In this way, it is possible to provide a power converter having a high operating rate by using a plurality of low-voltage inverter devices manufactured as standard products.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention.
It is a block configuration diagram of a power conversion device according to an embodiment of. About each part of this 2nd Embodiment, the 1st of FIG.
The same parts as those of the power conversion device according to the embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The second embodiment differs from the first embodiment in that the inverter output breaker 12 and the output transformer primary side short-circuit breaker 13 in the inverter cell 7 are removed, and instead the output transformer series is used. The connection breaker 14 and the output transformer secondary side short-circuit breaker 15 are installed corresponding to each inverter cell 7. That is, the secondary windings of the respective output transformers 5 are connected in series via the series connection breaker 14, and the secondary side short circuit breaker 15 is connected in series with the secondary winding of the output transformer 5. It is connected in parallel to the series circuit formed by 14.

Output transformer series connection circuit breaker 1 during normal operation
4 is turned on, and the output transformer secondary side short circuit breaker 15
Is open. When a failure occurs in one inverter cell 7 of the plurality of inverter cells 7, the failure detection device 8 of the corresponding inverter cell 7 detects the failure, gate-blocks the failed inverter cell 7, and further fails. By opening the output transformer series connection breaker 14 connected to the output transformer 5 of the inverter cell 7 and turning on the output transformer secondary side short-circuit breaker 15, the entire power conversion device failed. The inverter cell 7 is separated.

In this way, since the defective inverter cell 7 is bypass-operated on the secondary side of the output transformer 5, the power converter can be continuously operated, and the low-voltage inverter manufactured as a standard product. It is possible to provide a power conversion device having a high operating rate by using a plurality of devices.

(Third Embodiment) FIG. 3 shows a third embodiment of the present invention.
It is a block configuration diagram of a power conversion device according to an embodiment of. About each part of this 3rd Embodiment, the 1st of FIG.
The same parts as those of the power conversion device according to the embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The third embodiment differs from the first embodiment in that the inverter output breaker 12 and the output transformer primary side short-circuit breaker 13 in the inverter cell 7 are removed, and instead the inverter device 4 is used. The rectifier 16 and the switching element 17 are provided on the output side of the. The rectifier 16 provided on the output side has a bridge structure, and this DC output is short-circuited by the switching element 17.

During normal operation, the switching element 17 in each inverter cell 7 is off.

When a failure occurs in one inverter cell 7 among the plurality of inverter cells 7, the failure detection circuit 8 of the failed inverter cell 7 detects this and gate-blocks the failed inverter cell 7, Further, the switching element 17 in the defective inverter cell 7 is turned on to short-circuit the output of the inverter cell 7.

In this way, the defective inverter cell 7 can be substantially separated, and a plurality of low-voltage inverter devices manufactured as standard products can be used to provide a power converter with a high operating rate. .

(Fourth Embodiment) FIG. 4 shows a fourth embodiment of the present invention.
It is a block configuration diagram of a power conversion device according to an embodiment of. About each part of this 4th Embodiment, the 1st of FIG.
The same parts as those of the power conversion device according to the embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The fourth embodiment is different from the first embodiment in that the inverter output breaker 12 and the output transformer primary side short-circuit breaker 13 in the inverter cell 7 are removed and instead the inverter device 4 is used.
The switching element 17 is provided in each phase on the output side of the, and the rectifying element 19 and the cut-off switching element 18 connected in antiparallel with the switching element 17 are provided.

During normal operation, the switching element 17 in each inverter cell 7 is in the on state and the shut-off switching element 18 is in the off state, so that each inverter cell 7 supplies electric power via the switching element 17 and the rectifying element 19. We are supplying.

Next, the operation when a failure occurs will be described. When a failure occurs in one inverter cell 7 of the plurality of inverter cells 7, the failure detection circuit 8 of the failed inverter cell 7 detects the failure, gate-blocks the failed inverter cell 7, and further fails. Inverter cell 7
Switching element for disconnection 1 connected to each output phase in
8 is turned on, whereby the switching element 17 is turned off.

Even in this case, the defective inverter cell 7 can be substantially separated from the entire power converter, and the operation can be continued, and the operation can be performed by using a plurality of low-voltage inverter devices manufactured as standard products. A power conversion device with a high rate can be provided.

(Fifth Embodiment) FIG. 5 shows a fifth embodiment of the present invention.
It is a block configuration diagram of a power conversion device according to an embodiment of. Regarding each part of this fifth embodiment, the first part of FIG.
The same parts as those of the power conversion device according to the embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The fifth embodiment differs from the first embodiment in that the inverter input breaker 2 is provided in the input part of the smoothing circuit 3 in the inverter cell 7.
This is the point where 1 is added.

During normal operation, the inverter input breaker 21 is on. The operation when a failure occurs is shown below. When a failure occurs in one inverter cell 7 of the plurality of inverter cells 7, the failure detection circuit 8 of the failed inverter cell 7 detects this and gates the failed inverter cell 7 to shut off the inverter output. The switch 12 is opened, the output transformer primary side short circuit breaker 13 is closed, and the newly provided inverter input breaker 21 is opened. By this operation, the defective inverter cell 7 is separated from the entire power conversion device.

In this way, the defective inverter cell 7 can be completely separated and the operation can be continued, and a plurality of low-voltage inverter devices manufactured as standard products are used to further improve the operation rate of the power conversion device. Can be provided.

(Sixth Embodiment) FIG. 6 shows a sixth embodiment of the present invention.
It is a block configuration diagram of a power conversion device according to an embodiment of. About each part of this 6th Embodiment, the 1st of FIG.
The same parts as those of the power conversion device according to the embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The sixth embodiment differs from the first embodiment in that the phase signal of the PWM carrier wave in the inverter device 4 of each inverter cell 7 is obtained from the multi-PWM distribution device 20. is there.

The operation of the multi-PWM distribution device 20 is as follows. That is, when N inverter cells 7 of a control system called multi-PWM control are used, a phase that shifts the phase of the PWM control carrier frequency used in each inverter cell 7 by 360 degrees for N Output a signal. In this way, the output transformer 5
It is possible to reduce harmonics contained in the output voltage combined on the secondary side of the. Since the PWM waveforms of the output are combined while the phase is being shifted, the degree of reduction of harmonics has almost the same effect as N times the carrier frequency in one inverter.

In the sixth embodiment, if one inverter cell 7 fails during operation of the N inverter cells 7 under the multi PWM control by the multi PWM distributor 20, the failure corresponds to the failure. The failure detection device 8 in the inverter cell 7 detects the failure and the failed inverter cell 7
Block the gate of the inverter cell, and further open the inverter output circuit breaker 12 of the defective inverter cell 7 and at the same time close the output transformer primary side short circuit breaker 13, thereby removing the defective inverter cell 7 from the entire power converter. Separate.

On the other hand, the failure detection device 8 sends a failure signal to the multi-PWM distribution device 20. Multi PWM distribution device 20
In response to this, the phase signal corresponding to the multi-PWM control for the N-1 inverter cells is sent to the healthy N-1 inverter cells 7 to continue the operation.

By doing so, it is possible to provide a power converter having a high operating rate by using a plurality of low-voltage inverter devices manufactured as standard products, and even if one inverter cell fails, the highest harmonic It is possible to continue the operation of the power conversion device with the optimum PWM waveform with less.

When the multi-PWM control by the multi-PWM distribution device 20 is applied when one inverter cell 7 is operated as a standby system, the above-mentioned re-distribution operation is not necessary and the defective inverter cell It is sufficient to supply the same phase signal as that of the defective inverter cell 7 to the inverter cell 7 of the standby system which is turned on instead of the inverter 7.

Further, the multi-PWM distribution device 20 may not only generate the phase signal of the carrier wave, but may directly generate the gate signal of each inverter device 4. Furthermore, the multi-PWM distribution device 20 does not need to be installed independently of each inverter unit 7, and may be installed in the master inverter unit and supply the phase signal from there.

(Seventh Embodiment) FIG. 7 shows a seventh embodiment of the present invention.
It is a block configuration diagram of a power conversion device according to an embodiment of. About each part of this 7th Embodiment, the 5th of FIG.
The same parts as those of the power conversion device according to the embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The seventh embodiment is different from the fifth embodiment in that the secondary winding of the input transformer 1 is divided into a plurality of parts, a converter device 2 is provided for each winding, and the converter device 2 is multiplexed. It is the point of connection.

By shifting the phase of the secondary winding of the input transformer 1 and adopting the multiple connection method of the converter device 2, it is possible to reduce the inflow of the harmonic current into the input transformer 1, and Also, the voltage ripple on the DC bus can be reduced.

Also in this case, the separately excited converter is usually used as the converter. Although the converter device 2 in FIG. 7 is connected in series multiplex, it may be connected in parallel multiplex.

As described above, by using the converter devices 2 connected in multiple, it is possible to provide a power converter having a high operating rate by using a plurality of low-voltage inverter devices manufactured as standard products, and further input of the device. The waveform can be improved to have a sinusoidal shape.

(Eighth Embodiment) FIG. 8 shows an eighth embodiment of the present invention.
It is a block configuration diagram of a power conversion device according to an embodiment of. About each part of this 8th Embodiment, the 7th of FIG.
The same parts as those of the power conversion device according to the embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The eighth embodiment differs from the seventh embodiment in that a converter input fuse 22 is provided between a plurality of secondary windings of the input transformer 1 and a converter device 2 connected to each winding. Is the point where is inserted, and the connection method of the converter device 2 is changed from serial to parallel. Although not shown, each converter device 2 is provided with a converter failure detection device.

The operation when a failure occurs will be described below. When one converter device 2 out of a plurality of converter devices 2 fails, the converter failure detection device detects this and performs the gate block operation of the converter device 2. If this failure is a short-circuit failure of the converter device 2, the converter input fuse 22 is blown to disconnect the converter device 2 and continue the operation.

By doing so, a plurality of low-voltage inverter devices manufactured as standard products can be used to provide a power conversion device having a high operating rate in consideration of redundancy not only in the inverter device but also in the converter device. .

(Ninth Embodiment) FIG. 9 shows a ninth embodiment of the present invention.
It is a block configuration diagram of a power conversion device according to an embodiment of. About each part of this 9th Embodiment, the 8th of FIG.
The same parts as those of the power conversion device according to the embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The ninth embodiment differs from the eighth embodiment in that a converter input breaker is provided between a plurality of secondary windings of the input transformer 1 and a converter device 2 connected to each winding. The point where 23 is inserted,
And a DC bus circuit breaker 24 is inserted on the output side of each converter device 2.

The operation of the power converter of the present invention having the configuration of FIG. 9 will be described below. During normal operation, the converter input circuit breaker 23 and the DC bus circuit breaker 24 are closed.

When a failure occurs in one converter apparatus 2 among the plurality of converter apparatuses 2, the failure detection circuit of the failed converter apparatus 2 detects this and gate-blocks the corresponding converter apparatus 2. Further, open the converter input circuit breaker 23 and the DC bus circuit breaker 24,
The failed converter device 2 is reliably separated to continue the operation.

By doing so, a plurality of low-voltage inverter devices manufactured as standard products are used, and not only the inverter device but also the converter device is considered to have more reliable redundancy. A converter can be provided.

(Tenth Embodiment) FIG. 10 is a block configuration diagram of a power conversion device according to a tenth embodiment of the present invention. FIG. 7 shows the parts of this ninth embodiment.
The same parts as those of the power converter according to the seventh embodiment of the present invention are designated by the same reference numerals, and the description thereof will be omitted. The ninth embodiment differs from the seventh embodiment in that the input transformer 1 is changed to a transformer having a common primary winding.

By thus sharing the iron core of the input transformer, it is possible to provide a more economical power converter.

(Eleventh Embodiment) FIG. 11 is a block diagram of a power converter according to an eleventh embodiment of the present invention. With respect to each part of the eleventh embodiment, the same parts as those of the power conversion device according to the eighth embodiment of FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted. This first
The 0th embodiment is different from the 8th embodiment in that the converter device 2 is replaced with a self-excited conversion device.

By replacing the converter device 2 with a self-excited converter device, regenerative operation of the electric motor becomes possible, and by PWM controlling the converter device 2, it is possible to reduce input harmonics and improve input power factor. Becomes

By doing so, it is possible to provide a power converter with a high operating rate that can be regenerated and has good input characteristics by using a plurality of low-voltage inverter devices manufactured as standard products.

(Twelfth Embodiment) FIG. 12 is a block diagram of a power converter according to a twelfth embodiment of the present invention. With respect to each part of this twelfth embodiment, the same parts as those of the power conversion device according to the seventh embodiment of FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted. This first
The second embodiment is different from the seventh embodiment in that the inverter cells 7 connected in parallel to the DC power supply and the converter devices 2 connected in parallel to the DC bus are divided into two groups. Each of the inverter cell 7 and the converter device 2 is divided into a DC bus fuse 22
This is the point where connections are made at A and 22B.

With such a configuration, the converter device 2
Alternatively, when the inverter cell 7 fails, the DC bus fuses 22A or 22B connected to the respective groups are blown, so that the failed portion can be cut off by the DC bus to reduce the output and continue the operation. This idea is
It is suitable for applications in which continuous operation is prioritized even when the output is reduced to about half.

Even in this case, it is possible to provide a power converter having a high operating rate by using a plurality of low voltage inverter devices manufactured as standard products.

(Thirteenth Embodiment) FIG. 13 is a block diagram of a power converter according to a thirteenth embodiment of the present invention. With respect to each part of the thirteenth embodiment, the same parts as those of the power conversion device according to the twelfth embodiment of FIG. 12 are denoted by the same reference numerals, and the description thereof will be omitted. The thirteenth embodiment differs from the twelfth embodiment in that a DC busbar breaker 25 is inserted so as to connect the DC buses of the two divided groups.

In normal operation, DC busbar breaker 25
Open up. Consider a case where the DC bus fuse 22A on the converter device 2 side is blown due to an abnormality in the converter device 2. In this case, the DC bus connection breaker 25 is turned on, and about half the rated power is supplied from the sound converter device 2 to all the inverter cells 7 to continue the operation.
On the other hand, consider a case where the DC bus fuse 22B on the inverter cell 7 side is blown due to an abnormality on the inverter cell 7 side. In this case, the operation may be continued by using only the converter device 2 on one side, but the DC busbar circuit breaker 25 is turned on and the power of about half of the rated power is supplied so that the loads of the converter devices 2 are balanced. , The input waveform can be improved.

As described above, a plurality of low-voltage inverter devices manufactured as standard products can be used to provide a power conversion device having a high operating rate in consideration of the redundancy of the converter device.

(Fourteenth Embodiment) FIG. 14 is a block diagram of a power conversion device according to a fourteenth embodiment of the present invention. With respect to each part of the fourteenth embodiment, the same parts as those of the power conversion device according to the first embodiment of FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. This first
The fourth embodiment is different from the first embodiment in that an output transformer bypass circuit breaker 26 is added between the input side and the output side of the output transformer 5.

In the fourteenth embodiment of the present invention, the output transformer bypass circuit breaker 26 is closed at startup,
By bypassing the output transformer 5, operation is possible even in the low frequency range immediately after startup. After startup, when the output transformer 5 reaches a frequency capable of transmitting output, the output transformer bypass breaker 26 of each inverter cell 7 is opened to start normal operation.

In this way, it becomes possible to start the electric motor 6 at an extremely low frequency, which has been a problem in the characteristics of conventional transformers.

The first to fourteenth embodiments of the present invention described above are characterized in that the number of inverter cells 7 can be freely selected. That is, for example, if the power conversion device required for rated operation of the electric motor 6 requires N inverter cells 7, if a redundant system is assembled using N + 1 inverter cells 7, one inverter cell 7 will fail. Even so, it is possible to provide a system capable of continuous operation at full load. Alternatively, one of the inverter cells 7 may be placed in a standby state and the inverter cell 7 in the standby state may be turned on when a failure occurs in one of the plurality of inverter cells 7.

In the sixth to fourteenth embodiments of the present invention, the number of converter devices 2 can be freely selected.
That is, for example, if the power conversion device required for the rated operation of the electric motor 6 requires M converter devices 2, M +
If a redundant system on the converter side is assembled using one converter device 2, even if one converter device 2 fails,
It is possible to provide a system that can continue operation at full load. Alternatively, one of them may be placed in a standby state, and when one of the plurality of converter apparatuses 2 has a failure, the standby converter apparatus 2 may be turned on.

[0067]

According to the present invention, it is possible to provide a power converter having a high operating rate by using a plurality of low voltage inverter devices manufactured as standard products.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a power conversion device according to a first embodiment of the present invention.

FIG. 2 is a block configuration diagram of a power conversion device according to a second embodiment of the present invention.

FIG. 3 is a block configuration diagram of a power conversion device according to a third embodiment of the present invention.

FIG. 4 is a block configuration diagram of a power conversion device according to a fourth embodiment of the present invention.

FIG. 5 is a block configuration diagram of a power conversion device according to a fifth embodiment of the present invention.

FIG. 6 is a block configuration diagram of a power conversion device according to a sixth embodiment of the present invention.

FIG. 7 is a block configuration diagram of a power conversion device according to a seventh embodiment of the present invention.

FIG. 8 is a block configuration diagram of a power conversion device according to an eighth embodiment of the present invention.

FIG. 9 is a block configuration diagram of a power conversion device according to a ninth embodiment of the present invention.

FIG. 10 is a block configuration diagram of a power conversion device according to a tenth embodiment of the present invention.

FIG. 11 is a block configuration diagram of a power conversion device according to an eleventh embodiment of the present invention.

FIG. 12 is a block configuration diagram of a power conversion device according to a twelfth embodiment of the present invention.

FIG. 13 is a block configuration diagram of a power conversion device according to a thirteenth embodiment of the present invention.

FIG. 14 is a block configuration diagram of a power conversion device according to a fourteenth embodiment of the present invention.

[Explanation of symbols]

1 input transformer 2 converter device 3 smoothing circuit 4 Inverter device 5 output transformer 6 electric motor 7 Inverter cell 8 Failure detection device 11 fuse 12 Inverter output circuit breaker 13 Output transformer Primary side short circuit breaker 14 Output transformer series connection circuit breaker 15 Output transformer Secondary side short circuit breaker 16 Rectifier 17 Switching element 18 Switching element for breaking 19 Rectifying element 20 Multi PWM control circuit 21 Inverter input circuit breaker 22, 22A, 22B DC bus fuse 23 Converter input circuit breaker 24 DC bus circuit breaker 25 DC bus connection breaker 24 output transformer bypass circuit breaker

Continued front page    F-term (reference) 5H007 AA05 AA06 AA17 BB06 CA01                       CC05 CC33 DC02 FA03 FA13                       FA19 GA09

Claims (11)

[Claims] 1. A converter device for converting alternating current into direct current, a plurality of inverter devices connected in series to the converter device and connected in parallel with each other, and an output breaker on the output side of each of the inverter devices. Output transformers connected through the respective secondary sides in series with each other,
A fuse connected to the input side of each of the inverter devices, a short circuit breaker connected to the primary side of the output transformer so as to short-circuit the primary side of the output transformer, and And a failure detecting device for detecting a failure of the inverter device.When any of the failure detecting devices detects a failure of the inverter device, the inverter device is gate-blocked and the output circuit breaker is turned on. A power conversion device, characterized in that the faulty inverter device is disconnected by opening and closing the short circuit breaker. 2. A converter device for converting alternating current into direct current, a plurality of inverter devices connected in series to the converter device and connected in parallel with each other, and connected to output sides of the respective inverter devices, respectively. Output transformers whose secondary sides are connected in series with each other via a first circuit breaker, fuses connected to the input side of the respective inverter devices, the first circuit breaker and the output transformer A second circuit breaker connected in parallel to a series circuit formed by the secondary windings of the above-mentioned secondary windings, and respective failure detecting devices for detecting a failure of each of the inverter devices. Detects a failure of the inverter device, the gate of the corresponding inverter device is blocked, the first circuit breaker is opened, and the second circuit breaker is closed. A power conversion device characterized in that the power device is separated. 3. A converter device for converting alternating current into direct current, a plurality of inverter devices connected in series to the converter device and connected in parallel with each other, and connected to output sides of the respective inverter devices, respectively. Output transformers whose secondary sides are connected in series with each other, fuses connected to the input sides of the respective inverter devices, and the outputs of the inverter devices to the output side of the respective inverter devices are short-circuited or opened. And a failure detection device for detecting a failure of the inverter device. When any of the failure detection devices detects a failure of the inverter device, the corresponding inverter device is detected. Block the gate circuit, and further short-circuit or open the semiconductor circuit so as to disconnect the defective inverter device. A power conversion device characterized by the above. 4. An input circuit breaker is provided on the input side of each of the inverter devices, and when any of the failure detection devices detects a failure of the inverter device, the input circuit breaker is opened to ensure reliability. The power conversion device according to any one of claims 1 to 3, wherein the failed inverter device is disconnected. 5. A plurality of inverter devices connected in parallel are controlled by multi-PWM, and when any one of the inverter devices fails, the corresponding inverter device is disconnected and the remaining inverter devices are separated. The power converter according to any one of claims 1 to 4, wherein the phase signal of the carrier wave generated by the multi-PWM distributor is redistributed. 6. The power conversion device according to claim 1, wherein the converter device is multiplexed. 7. The converter device is multiplexed, and a fuse or a circuit breaker is provided in at least one of an input and an output of each converter device, and when a failure occurs in any of the converter devices, the corresponding converter device is gated. The power converter device according to any one of claims 1 to 5, wherein the converter device that is blocked and broken is disconnected by at least one of the fuse and the circuit breaker. 8. A plurality of converter devices and a plurality of inverter devices, each of which are connected in parallel to the DC busbar, are provided in two units.
Divide into groups, connect each group of the converter device and the inverter device to a DC bus through a fuse, and when either the converter device or the inverter device fails, the fuse operates to cause a failure. The power converter device according to claim 6 or 7, wherein the converter device or the inverter device group is separated. 9. A group in which a converter device and an inverter device connected in parallel to a DC bus bar are divided into two groups, and the converter device and the inverter device in the group are respectively connected to the DC bus bar through fuses. And then connect the DC busbars between the groups via a circuit breaker, and during normal operation, the circuit breaker is opened to perform operation, and either the converter device or the inverter device fails. The power converter according to claim 6 or 7, wherein when the fuse operates, the circuit breaker is turned on to connect the sound converter device or the inverter device to continue the operation. apparatus. 10. The power conversion device according to claim 1, wherein a regenerative converter device is used as the converter device. 11. A bypass circuit breaker configured to bypass an output transformer connected to the output of the inverter device, wherein the bypass circuit breaker is closed when the load motor is started to bypass the output transformer. The power conversion device according to claim 1, wherein the power conversion device is a power conversion device.