JP2008172925A - Backup operation device of matrix converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a backup operation device of a matrix converter which can back up and operate the matrix converter even if there occur failures of two elements which constitute a series circuit between AC power supply phases over two input phases. <P>SOLUTION: The backup operation device of the matrix converter includes: a backup DC power supply (21); a backup semiconductor switch group (23) for one phase of an input phase; a failed-switch detection means (10) which detects the input phase to which a failed semiconductor switch in the matrix converter is connected; a connection phase switching selection means (22) which connects the backup DC power supply between the input phase of one phase other than the input phase in which a failure is detected and an input of the backup semiconductor switch group when the failure is detected by the failed-switch detection means; and a control means (7) which turns off the semiconductor switch connected to the input phase to which a direct current is fed by the connection phase switching selection means, and turns off all the other semiconductor switches. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a matrix converter backup operation apparatus that performs a backup operation when a semiconductor switch of a matrix converter fails.

  A conventional matrix converter backup operation apparatus includes a matrix converter that converts a polyphase AC voltage into a polyphase AC voltage using a virtual rectifier and a virtual inverter, and synthesizes control pulses for the virtual rectifier and the virtual inverter and applies them to the matrix converter. -Relating to AC power converters. Power supply abnormality detection means for detecting abnormality of the multiphase AC voltage on the power supply side, and when a power supply abnormality is detected, DC voltage is supplied to the input phase of the virtual rectifier instead of the polyphase AC voltage supplied to the virtual rectifier And a rectifier control means for turning on a predetermined semiconductor switch and turning off another semiconductor switch in accordance with a switch-on command so that a DC voltage appears in the virtual DC link section of the matrix converter. (For example, refer to Patent Document 1).

According to this matrix converter backup operation device, in an AC-AC power converter that does not have a large-capacity energy buffer such as a matrix converter, a DC voltage is applied to the input phase even when a power supply abnormality occurs or a semiconductor switch fails. Supplying and controlling on / off of a predetermined semiconductor switch enables continuous operation.
In addition, since it can be provided at a low cost with a relatively simple circuit configuration as compared with the prior art equipped with an uninterruptible power supply, improvement in reliability and economy can be expected.

JP 2004-254360 A

According to this conventional matrix converter backup operation apparatus, when a semiconductor switch connected to one input phase fails, a backup operation can be performed.
However, one element failure is usually not likely to occur. If one of the semiconductor elements fails, the other phase semiconductor elements that form a series circuit between AC power supply phases will also fail. Therefore, there is a high possibility of a two-element failure, but there is a problem that the conventional matrix converter backup operation device cannot perform the backup operation.

  An object of the present invention is to provide a matrix converter backup operation apparatus capable of performing a backup operation even in the case of a failure of two elements constituting a series circuit between AC power supply phases over two input phases.

  In the matrix converter backup operation device according to the present invention, the input phase and the multiphase AC motor are connected to the output phase through contacts that are closed during normal operation and opened during a power failure or backup operation. In addition, in a backup operation device for a matrix converter, which is constituted by a semiconductor switch and performs a backup operation of the matrix converter that controls the multiphase AC motor by switching the semiconductor switch, a backup DC power supply and a backup for one phase of the input phase A failure switch detecting means for detecting an input phase to which the failed semiconductor switch in the matrix converter is connected; and the failure is detected when the failure is detected by the failure switch detecting means. Any other than the input phase Connected phase switching selection means for connecting the backup DC power source between the input phase of the phase and the input of the backup semiconductor switch group, and connected to the input phase supplied with DC by the connection phase switching selection means. And a control means for turning off all the other semiconductor switches.

  The effect of the matrix converter backup operation device according to the present invention is that all the semiconductor switches connected to the faulty phase are fixed in the OFF state, and a direct current is connected between one of the other healthy phases and the line of the backup semiconductor switch group. A backup circuit is configured by connecting a power supply, and the semiconductor switches constituting the backup circuit are controlled to be turned on and off, so that the backup circuit can be operated as an inverter and AC power having a desired amplitude and frequency can be generated. And even if a semiconductor switch fails over two input phases, it is possible to continue the operation without degrading the control performance.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram showing the configuration of a matrix converter backup operation apparatus according to Embodiment 1 of the present invention.
The matrix converter 3 according to the first embodiment of the present invention will be described assuming that the number of phases of the input phase and the output phase is the most general three phases, but is not limited to this. Then, each phase of the input phase and the AC input terminal are R, S, and T, and each phase of the output phase and the AC output terminal are U, V, and W.
The matrix converter 3 according to the first embodiment of the present invention converts the AC power input from the three-phase AC power source 1 into desired AC power, and supplies it to the motor 2 for control. Then, three-phase AC power is input to the AC input terminals R, S, and T from the three-phase AC power source 1, and the converted AC power is output from the AC output terminals U, V, and W and supplied to the electric motor 2.

  The matrix converter backup operation apparatus according to the first embodiment of the present invention includes a matrix converter 3, an input opening / closing means 5 for opening / closing a connection between the three-phase AC power supply 1 and the matrix converter 3, and semiconductor switches 31 to 31 in the matrix converter 3. As a control means for controlling the failure switch detection means 10 for detecting 39 failures, the backup means 4 constituting part of the backup circuit, the matrix converter 3 and the backup means 4 when a failure of the semiconductor switches 31 to 39 is detected. Matrix converter control means 7 is provided.

The matrix converter 3 includes bidirectional semiconductor switches 31 to 39. In the semiconductor switches 31 to 39, two semiconductor switching elements such as IGBTs are connected in series in the reverse direction, and a free-wheeling diode is connected in antiparallel to each semiconductor switching element. Note that an IGBT having reverse breakdown voltage may be connected in reverse parallel.
By switching control of the bidirectional semiconductor switches 31 to 39, the three-phase motor 2 connected to the AC output terminals U, V, and W is controlled.

  Although not shown, the failure switch detection means 10 is connected to the input phase to detect the phase and amplitude of the input three-phase alternating current and transmit it to the controller, and a gate signal sent to the matrix converter 3. An output voltage detector for detecting a voltage output by turning on the semiconductor switches 31 to 39, and an input voltage value to the driven semiconductor switches 31 to 39 by driving the semiconductor switches 31 to 39 based on the diagnosis pattern at the time of failure diagnosis If the output voltage values of the matrix converter 3 and the matrix converter 3 match each other, it is determined to be normal, and if it is excessive or too small, it is determined to be abnormal, and the failure of the failed semiconductor switches 31 to 39 is specified from the result of each pass / fail determination for each diagnostic pattern A controller is provided.

The input switching means 5 includes contacts 51 to 53 that open and close between the three-phase AC power source 1 and the AC input terminals R, S, and T for each input phase, and a failure detection signal sent from the failure switch detection means 10. To open all contacts.
The backup means 4 receives the outputs of the backup DC power supply 21 and the failure switch detection means 10 and connects the input terminal of any one phase other than the failure phase with the backup DC power supply 21 and inputs the connection phase switching selection means 22. A backup semiconductor switch group 23 for one phase is provided.
The backup semiconductor switch group 23 includes bidirectional semiconductor switches 41 to 43.

  The matrix converter control means 7 controls the matrix converter 3 in normal times. The matrix converter control means 7 receives the failure phase detection signal from the failure switch detection means 10 and the connection phase information from the connection phase switching selection means 22 when the semiconductor switch in the matrix converter 3 fails, All the semiconductor switches in the matrix converter 3 connected to the input terminals other than the phase are turned off, and one sound input phase in the matrix converter 3 to which the backup DC power supply 21 is connected and the backup semiconductor The switch group 23 is controlled to be turned on / off, and a backup operation is performed.

  Next, the operation of the matrix converter backup operation apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 2 is a circuit diagram illustrating an example of a matrix converter in which a semiconductor switch has failed. FIG. 3 is a circuit diagram of an inverter circuit configured as a backup circuit during backup operation.

In the matrix converter 3 shown in FIG. 2, since the semiconductor switches 33 and 36 (semiconductor switches represented by black circles in FIG. 2) respectively connected to the input terminal R and the input terminal S have failed, the failure switch detection means 10 Indicates that the same input phase (hereinafter referred to as “failure phase”) of the failed semiconductor switches 33 and 36 as the failure phase detection signal is the R phase and the S phase; Send to 5.
Since the failure phase is the R phase and the S phase, the connection phase switching selection means 22 selects the T phase which is one of the other input phases (hereinafter referred to as “healthy phase”) as the connection phase, and the input terminal T is connected to the backup DC power source 21. Further, it transmits to the matrix converter control means 7 that the connection phase is the T phase as connection phase information. Since the number of input phases is three, the healthy phase is limited to the T phase, but when the number of phases is four or more, there are two or more healthy phases. Select.
The input opening / closing means 5 opens all the contacts 51 to 53.

When the input opening / closing means 5 and the connection phase switching selecting means 22 operate in this way, the backup circuit shown in FIG. 3 is configured. This backup circuit is an inverter circuit, and the upper arm is constituted by a backup semiconductor switch group 23 and the lower arm is constituted by semiconductor switches 37 to 39 connected to the T phase. Then, the DC power of the backup DC power supply 21 can be converted into AC power by the inverter circuit.
The matrix converter control means 7 performs on / off control of the semiconductor switches 37 to 39 and 41 to 43 constituting the inverter circuit, so that AC power for driving the three-phase motor 2 is output to the output terminals U, V, and W.

  The matrix converter backup operation apparatus according to the first embodiment fixes all the semiconductor switches 31, 32, 34, and 35 connected to the failure phase in the OFF state, and one of the other healthy phases is used for backup. A backup DC power source 21 is connected between the lines of the semiconductor switch group 23 to constitute a backup circuit, and the semiconductor switches 37 to 39 and 41 to 43 constituting the backup circuit are controlled to be turned on / off. A simple backup circuit can be operated as an inverter, and AC power having a desired amplitude and frequency can be generated.

The matrix converter backup operation apparatus according to the first embodiment can continue the operation without degrading the control performance even when the semiconductor switch fails over the two input phases.
In the above description of the first embodiment, an example of an open failure has been described. However, if there is one failure for each phase, a backup operation is possible even in a short-circuit failure. In addition, backup operation during a power failure is also possible.

  In the first embodiment, the upper arm of the inverter circuit is constituted by the backup semiconductor switch group 23 and the lower arm is constituted by the semiconductor switches 37 to 39 connected to the T phase. Similarly, in the backup means 4B shown in FIG. 4, the polarity of 21B is reversed, the lower arm is constituted by the semiconductor switch group 23B for backup, and the upper arm is constituted by the semiconductor switch connected to the healthy phase. Backup operation can be performed.

Embodiment 2. FIG.
FIG. 5 is a circuit diagram of backup means according to Embodiment 2 of the present invention.
The matrix converter backup operation device according to the second embodiment of the present invention is different from the matrix converter backup operation device according to the first embodiment in that the backup means 4C is the same. The same reference numerals are given and description thereof is omitted.
The backup means 4C according to the second embodiment of the present invention is the same as the backup means 4 according to the first embodiment except that the backup means 4 and the backup semiconductor switch group 23C are the same. Additional description will be omitted.

The backup semiconductor switch group 23C is composed of semiconductor switches 41C to 43C in which diodes are connected in reverse parallel to IGBTs that are unidirectional semiconductor switching elements having no reverse breakdown voltage.
The matrix converter backup operation apparatus according to the second embodiment provides an inexpensive matrix converter backup operation apparatus because the backup semiconductor switch group 23C is composed of a unidirectional semiconductor switching element such as an IGBT and a diode. can do.

Embodiment 3 FIG.
FIG. 6 is a block diagram showing the configuration of the matrix converter backup operation apparatus according to Embodiment 3 of the present invention.
The matrix converter backup operation apparatus according to the third embodiment of the present invention is different from the matrix converter backup operation apparatus according to the second embodiment in the backup means 4D. The same reference numerals are given and description thereof is omitted.

The backup means 4D according to Embodiment 3 of the present invention is inputted to the input phase of the matrix converter 3, the first full-wave rectifier circuit 61 for full-wave rectifying the three-phase AC power, and the input to the output phase of the matrix converter 3. A second full-wave rectifier circuit 62 for full-wave rectifying the phase AC power, a capacitor 63 and a discharge circuit 64 connected in parallel to the DC side of the first full-wave rectifier circuit 61 are provided.
Further, the backup means 4D receives the output of the backup DC power supply 21 having the positive pole connected to the positive terminal P on the DC side of the first full-wave rectifier circuit 61 and the failure switch detection means 10, and receives any output other than the failure phase. A semiconductor switch 41C comprising a semiconductor switching element connected in reverse parallel to each of the upper phase diode of the second full-wave rectifier circuit 62 and the connection phase switching selection means 22 for connecting the one-phase input terminal to the backup DC power source 21. The semiconductor switch group 23C for backup comprised from -43C is provided.

  The first full-wave rectifier circuit 61, the second full-wave rectifier circuit 62, the capacitor 63, and the discharge circuit 64 constitute a snubber circuit. Further, when a failure of the semiconductor switch of the matrix converter 3 is detected by the backup DC power source 21, the connection phase switching selection means 22 and the backup semiconductor switch group 23C, it is used for the configuration of the backup circuit. Since the configuration of this backup circuit is the same as that of the second embodiment, description thereof is omitted.

  The matrix converter backup operation apparatus according to the third embodiment is configured by adding three unidirectional semiconductor switching elements having no reverse withstand voltage to the snubber circuit required for normal operation of the matrix converter 3. Therefore, it is possible to provide an inexpensive matrix converter backup operation device.

  In the above-described third embodiment, the semiconductor switching element of the backup semiconductor switch group 23 is connected in reverse parallel to the diode of the upper arm of the second full-wave rectifier circuit 62. As shown in FIG. Even if the semiconductor switching element of the backup semiconductor switch group 23 is connected in reverse parallel to the diode of the lower arm of the two full-wave rectifier circuit 62, the backup operation can be similarly performed.

It is a block diagram showing the structure of the backup operation apparatus of the matrix converter concerning Embodiment 1 of this invention. It is a circuit diagram showing the example of the matrix converter in which the semiconductor switch failed. It is a circuit diagram of the inverter circuit comprised as a backup circuit at the time of backup operation. It is a block diagram which shows the structure of another backup means concerning Embodiment 1 of this invention. It is a block diagram showing the structure of the backup means concerning Embodiment 2 of this invention. It is a block diagram showing the structure of the backup operation apparatus of the matrix converter concerning Embodiment 3 of this invention. It is a block diagram which shows the structure of another backup means concerning Embodiment 3 of this invention.

Explanation of symbols

  1 3-phase AC power supply, 2 3-phase motor, 3 matrix converter, 4, 4B, 4C, 4D backup means, 5 input switching means, 7 matrix converter control means, 10 fault switch detection means, 21, 21B DC power supply for backup, 22 connected phase switching selection means, 23, 23B, 23C backup semiconductor switch group, 31-39, 41-43 semiconductor switch, 51, 52 contacts, 61, 62 full-wave rectifier circuit, 63 capacitor, 64 discharge circuit.

Claims (4)

The multi-phase AC power supply is closed during normal operation and opened during a power failure or backup operation. The input phase and the multi-phase AC motor are connected to the output phase via a contact, and the semiconductor switch is configured by a semiconductor switch. In the matrix converter backup operation device for performing the backup operation of the matrix converter for controlling the multiphase AC motor,
DC power supply for backup,
A group of backup semiconductor switches for one input phase;
Fault switch detection means for detecting an input phase to which a faulty semiconductor switch in the matrix converter is connected;
When a failure is detected by the failure switch detection means, the backup DC power supply is connected between any one input phase other than the input phase where the failure is detected and the input of the backup semiconductor switch group. Connection phase switching selection means to be connected;
Control means for turning on and off the semiconductor switch connected to the input phase supplied with direct current by the connection phase switching selection means, and turning off all other semiconductor switches;
A matrix converter backup operation apparatus comprising:   2. The matrix converter backup operation apparatus according to claim 1, wherein the backup semiconductor switch group for one input phase includes three bidirectional reverse withstand voltage semiconductor switches.   2. The backup semiconductor switch group for one phase of the input phase is constituted by three unidirectional semiconductor switching elements having no reverse breakdown voltage in which diodes are connected in reverse parallel. Matrix converter backup operation device. A snubber circuit connected between the input phase and the output phase of the matrix converter and having two full-wave rectifier circuits and a capacitor;
The backup semiconductor switch group for one input phase does not have a reverse breakdown voltage connected in reverse parallel to the upper three rectifier elements of the full-wave rectifier circuit of the snubber circuit connected to the output phase. 2. The matrix converter backup operation device according to claim 1, wherein the matrix converter backup operation device is constituted by a directional semiconductor switching element.

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