JP2014117116A - Control device of power conversion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a power conversion apparatus capable of determining which system in multiplex-system gate pulses is abnormal.SOLUTION: There is provided a gate pulse generator 1 configured to ignite a thyristor 22 by duplex-system gate pulses GPa, GPb. When gate pulses GPa, GPb of a system that ignites the thyristor 22 first are selected from duplex-system gate pulses GPa, GPb, ignition of the thyristor 22 is detected, and the detected ignition of the ignition thyristor 22 is determined as not being performed by the gate pulses of the system that ignites the thyristor 22 first, the system is determined as being abnormal.

Description

  The present invention relates to a control device that controls a power converter.

  In general, a power conversion device using a switching element is known. The switching element is driven by a gate pulse. In addition, in order to improve the operation continuity against a failure, it is known that the switching element is driven by a gate pulse configured in a double system. For example, gate control of a thyristor valve in which gate pulses are generated by two sets of gate pulse generators is disclosed (see Patent Document 1).

JP-A-9-322524

  However, when the switching element is driven by a double gate pulse, even if the one-system gate pulse is abnormal, the switching element is driven normally, so it is not known which system is abnormal.

  Accordingly, an object of the present invention is to provide a control device for a power conversion device that can determine which of the multiple gate pulses is abnormal.

  A control device for a power conversion device according to an aspect of the present invention is a control device for a power conversion device that ignites a switching element by a multi-system gate pulse. Gate pulse selection means for selecting a gate pulse of the system to be fired on, ignition detection means for detecting the ignition of the switching element, and ignition of the switching element detected by the ignition detection means, When it is determined that the system has not been fired by the gate pulse of the system selected by the gate pulse selection unit, the system includes an abnormality determination unit that determines that the system is abnormal.

  ADVANTAGE OF THE INVENTION According to this invention, the control apparatus of the power converter device which can determine which system is abnormal among the multiplex system gate pulses can be provided.

The block diagram which shows the structure of the power converter device to which the gate pulse generator which concerns on embodiment of this invention is applied. FIG. 3 is a simplified diagram showing a first pulse pattern generation method according to the present embodiment. FIG. 5 is a simplified diagram showing a second pulse pattern generation method according to the present embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment)
FIG. 1 is a configuration diagram showing a configuration of a power conversion device to which a gate pulse generator 1 according to an embodiment of the present invention is applied. In addition, the same code | symbol is attached | subjected to the same part in drawing, the detailed description is abbreviate | omitted, and a different part is mainly described.

  The gate pulse generator 1 is incorporated in a VBE (valve base electronics) board. The VBE board is a control device that controls the thyristor valve 2. The gate pulse generator 1 is a double gate pulse for driving the thyristor 22 of the thyristor valve 2 based on a thyristor valve control signal (TVC (thyristor valve control) signal) Stvc received from the control panel 3 of the host control system. GPa and GPb are generated.

  The thyristor valve 2 is a power conversion device including a plurality of thyristors 22. In the thyristor valve 2, two laser diode units 21 a and 21 b, one resistor 23, and one forward voltage detector 24 are provided for one thyristor 22. Here, the configuration of one thyristor 22 will be mainly described, and the description of the other thyristor 22 is omitted because it is configured similarly.

  The thyristor 22 is a switching element that constitutes a power conversion circuit. The thyristor 22 is an optical trigger thyristor that is ignited by an optical signal.

  The two laser diode units 21a and 21b are configured in a double system including an A system and a B system. The A-system laser diode unit 21 a outputs an A-system optical signal (gate pulse) for firing the thyristor 22 by the A-system gate pulse GPa received from the gate pulse generator 1. The B-system laser diode unit 21 b outputs a B-system optical signal (gate pulse) for firing the thyristor 22 by the B-system gate pulse GPb received from the gate pulse generator 1.

  The resistor 23 is a voltage dividing resistor for uniformly dividing a DC voltage component applied between the poles of the thyristor valve 2 to each thyristor 22. Further, the resistor 23 suppresses a current flowing through the forward voltage detector 24.

  The forward voltage detector 24 is a detector for detecting a voltage (hereinafter referred to as “forward voltage”) applied in the forward direction of the thyristor 22 (direction in which current flows through the thyristor). The forward voltage detector 24 outputs an FV signal (forward voltage signal) Sfv when the thyristor 22 is off. Therefore, the forward voltage detector 24 does not output the FV signal Sfv when the thyristor 22 is fired (turned on). The forward voltage detector 24 is composed of a light emitting diode. The light emitting diode emits light using a voltage generated by the impedance of the snubber circuit. The light emitted from the light emitting diode is output to the gate pulse generator 1 of the VBE board as the FV signal Sfv through the light guide.

  The gate pulse generator 1 includes a pulse pattern selection unit 11, a gate pulse output unit 12, and a failure detection unit 13.

  When receiving the TVC signal Stvc from the control board 3, the pulse pattern selection unit 11 selects one of the two pulse patterns PT1 and PT2 shown in FIGS. In the pulse patterns PT1 and PT2, the order of the gate pulses of the system for turning on the thyristor 22 is determined in advance. By selecting the pulse patterns PT1 and PT2, a system for first turning on the thyristor 22 is determined. The pulse pattern selection unit 11 may select any method for selecting the pulse patterns PT1 and PT2. For example, the pulse pattern selection unit 11 alternately selects two pulse patterns PT1, PT2. The pulse pattern selection unit 11 outputs the selected pulse patterns PT1 and PT2 to the gate pulse output unit 12 and the failure detection unit 13.

  The gate pulse output unit 12 outputs the gate pulses GPa and GPb to the laser diode units 21a and 21b of both systems of the thyristor valve 2 according to the pulse patterns PT1 and PT2 selected by the pulse pattern selection unit 11, respectively.

  FIG. 2 is a simplified diagram showing a method for generating the first pulse pattern PT1. FIG. 3 is a simplified diagram showing a method for generating the second pulse pattern PT2.

  In the first pulse pattern PT1, the A pulse P is input to the thyristor 22 earlier than the B pulse Pb. Therefore, if both the A system and the B system are normal, the thyristor 22 is turned on by the A system pulse Pa. That is, when the A-system pulse Pa is generated at time t1, and then the B-system pulse Pb is generated at time t2, the thyristor 22 is normally turned on by the A-system pulse Pa at approximately time t1.

  In the second pulse pattern PT2, the B pulse Pb is input to the thyristor 22 earlier than the A pulse P. Therefore, if both the A system and the B system are normal, the thyristor 22 is turned on by the B system pulse Pb. That is, when the B-system pulse Pb is generated at time t1 and thereafter the A-system pulse Pa is generated at time t2, the thyristor 22 is normally turned on by the B-system pulse Pb at approximately time t1.

  The failure detection unit 13 detects an A-system or B-system failure based on the FV signal Sfv detected by the forward voltage detector 24 and the pulse patterns PT1 and PT2 selected by the pulse pattern selection unit 11. When the failure detection unit 13 detects a failure, it outputs a failure detection signal NG. The failure detection signal NG is output to a display device or devices.

  For example, the display device that has received the failure detection signal NG displays whether the failure is in the A system or the B system. Thereby, the administrator or the like can know the failure of the A system or the B system. In addition, the devices that have received the failure detection signal NG can automatically perform an operation for responding to a failure in the A system or the B system.

  Next, a failure detection method by the failure detection unit 13 will be described.

  When the first pulse pattern PT1 is selected, the failure detector 13 detects an A-system failure (for example, a failure of the A-system laser diode unit 21a). When the second pulse pattern PT2 is selected, the failure detection unit 13 detects a B-system failure (for example, a failure of the B-system laser diode unit 21b).

  First, a case where the first pulse pattern PT1 selected by the pulse pattern selection unit 11 is selected will be described.

  In the case of the first pulse pattern PT1, if the A system is normal, the thyristor 22 is turned on by the A system pulse Pa first input to the thyristor 22. When the thyristor 22 is turned on, the FV signal Sfv disappears. Thereafter, even if the B-system pulse Pb is input to the thyristor 22, since the thyristor 22 has already been turned on, the FV signal Sfv remains extinguished. The failure detection unit 13 determines the time when the thyristor 22 is turned on based on the time when the FV signal Sfv disappears.

  Here, if the system A is normal, the thyristor 22 is turned on at time t1 shown in FIG. That is, the thyristor 22 is turned on by the A-system pulse Pa. On the other hand, if there is an abnormality in the A system, the thyristor 22 is turned on at time t2 shown in FIG. That is, the thyristor 22 is turned on by the B-system pulse Pb.

  When the failure detection unit 13 receives a signal indicating the pulse pattern PT1 selected from the pulse pattern selection unit 11, the failure detection unit 13 predicts a time t1 at which the thyristor 22 is turned on by the A-system pulse Pa first input to the thyristor 22. The failure detection unit 13 predicts a time t1 at which the thyristor 22 is turned on in consideration of transmission time, operation time of various detectors, calculation processing time, and the like. The failure detection unit 13 may receive another signal in order to predict the time t1 when the thyristor 22 is turned on. For example, the failure detection unit 13 may receive a signal indicating that the gate pulses GPa and GPb are output from the gate pulse output unit 12 when the gate pulses GPa and GPb are output from the gate pulse output unit 12. Good.

  The failure detection unit 13 determines whether or not the time when the thyristor 22 measured by the disappearance of the FV signal Sfv is actually turned on is substantially the same as the time t1 when the thyristor 22 is predicted to be turned on. If the failure detection unit 13 determines that the thyristor 22 is not turned on at the predicted time t1, the failure detection unit 13 determines that the A system is in failure. Specifically, the failure detection unit 13 determines that the A system is in failure if the FV signal Sfv does not disappear within a preset time from the predicted time t1. On the other hand, when the failure detection unit 13 determines that the thyristor 22 is turned on at the predicted time t1, the failure detection unit 13 determines that the A system is normal.

  Next, a case where the second pulse pattern PT2 selected by the pulse pattern selection unit 11 is selected will be described. Since this is basically the same as when the first pulse pattern PT1 is selected, a brief description will be given.

  When the failure detection unit 13 receives the signal indicating the pulse pattern PT2 selected from the pulse pattern selection unit 11, the failure detection unit 13 predicts the time t1 shown in FIG. 3 when the thyristor 22 is turned on if the B system is normal. If the failure detection unit 13 determines that the thyristor 22 is not turned on at the predicted time t1 due to the disappearance of the received FV signal Sfv, the failure detection unit 13 determines that the B system is in failure. On the other hand, when the failure detection unit 13 determines that the thyristor 22 is turned on at the predicted time t1, the failure detection unit 13 determines that the B system is normal.

  According to the present embodiment, in the gate pulse generator 1 that ignites the thyristor 22 with the double gate pulses GPa and GPb, by providing a time difference between the outputs of the A gate pulse GPa and the B gate pulse GPb, It is possible to detect whether an abnormality has occurred in either the A system or the B system.

  In the present embodiment, the configuration for driving the thyristor 22 has been described. However, as long as the switching element is switched by a gate pulse, an element other than the thyristor may be driven. The switching element is not limited to being driven by an optical signal, but may be driven by an electrical signal.

  In the present embodiment, the configuration in which the thyristor 22 is driven by the dual gate pulses GPa and GPb has been described. However, the configuration is not limited to the dual system, and may be configured by a multiple system. First, an abnormality in each system can be detected by selectively changing the gate pulse of the system that drives the switching element.

  In this embodiment, the ignition of the thyristor 22 is detected by the FV signal Sfv. However, any configuration may be used as long as the ignition of the thyristor 22 can be detected.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 1 ... Gate pulse generator, 2 ... Thyristor valve, 3 ... Control board, 11 ... Pulse pattern selection part, 12 ... Gate pulse output part, 13 ... Failure detection part, 21a, 21b ... Laser diode unit, 22 ... Thyristor, 23 ... resistance, 24 ... forward voltage detector, GPa, GPb ... gate pulse, NG ... failure detection signal, Stvc ... TVC signal, Sfv ... FV signal.

Claims (5)

A control device for a power conversion device that ignites a switching element by a multi-system gate pulse,
Gate pulse selection means for selecting a gate pulse of the system that first ignites the switching element among the gate pulses of the multiple system;
Ignition detection means for detecting the ignition of the switching element;
An abnormality that determines that the system is abnormal when it is determined that the ignition of the switching element detected by the ignition detection means is not ignited by the gate pulse of the system selected by the gate pulse selection means And a control unit for the power conversion device. 2. The control device for a power converter according to claim 1, wherein the gate pulse selecting means selects a pulse pattern in which a gate pulse of a system for igniting the switching element is determined in advance. The control device for a power conversion apparatus according to claim 1 or 2, wherein the abnormality determination unit detects ignition of the switching element based on a voltage between terminals of the switching element. A control method of a power converter that ignites a switching element by a multi-system gate pulse,
Selecting a gate pulse of the system that first fires the switching element among the gate pulses of the multiple system;
Detecting the ignition of the switching element;
A control method for a power converter, comprising: determining that the detected switching element is not ignited by a gate pulse of the selected system, and determining that the system is abnormal. A switching element ignited by a multi-system gate pulse;
Gate pulse selection means for selecting a gate pulse of the system that first ignites the switching element among the gate pulses of the multiple system;
Ignition detection means for detecting the ignition of the switching element;
An abnormality that determines that the system is abnormal when it is determined that the ignition of the switching element detected by the ignition detection means is not ignited by the gate pulse of the system selected by the gate pulse selection means A power conversion device comprising: a determination unit.

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