JP2021191069A - Inspection method of power conversion device - Google Patents

Abstract

To provide an inspection method of a power conversion device, capable of simply inspecting the presence/absence of an abnormality of an optical divider.SOLUTION: An inspection method of a power conversion device, comprises: a plurality of thyristors that are connected in series; a plurality of voltage detectors that are provided so as to detect both end voltages of the plurality of thyristors, and output logical values in accordance with ON/OFF of the plurality of thyristors; a power converter that contains an optical divider dividing a first optical fiber and a plurality of second optical fibers connected to the optical divider and supplying a gate signal to the plurality of thyristors; and a gate control device that supplies the gate signal to the first optical fiber. A DC voltage is applied to between first and second terminals, an optical signal is transmitted from the first optical fiber, and the logical arithmetic operation of the plurality of logical values output from the plurality of voltage detectors is performed. On the basis of arithmetic results by the plurality of logical values, the determination is made so that any one of the first and second fibers and the optical divider has a failure.SELECTED DRAWING: Figure 2

Description

An embodiment of the present invention relates to an inspection method for a power conversion device.

The power conversion device includes a power converter that mutually converts power between AC and DC, and a gate control device and a control panel that supply a gate signal to the power converter to control the power conversion operation. The power converter may have a high voltage and is often installed at a location away from the gate controller.

The thyristor is connected to the gate control device via an optical fiber and is ignited by a gate signal generated by the gate control device. The power converter uses thyristors connected in series in multiple stages according to the voltage to be handled. Therefore, depending on the number of thyristors used, the number of long optical fibers increases, and the cost of the optical fiber itself and the installation cost may become high.

The gate signal supplied to the thyristor is the same signal in the thyristor bulb of the same phase, so if one optical fiber is branched and supplied in or near the power converter, a long optical fiber can be supplied. The number can be reduced.

By adding a circuit element for an optical signal such as an optical splitter that splits the optical fiber and distributes the optical signal transmitted through the optical fiber, it is possible to reduce the number of long optical fibers. On the other hand, there is a demand for an inspection method that can easily determine the presence or absence of such an abnormality of the optical splitter at the time of installation of the power conversion device and at regular or irregular inspections.

Japanese Unexamined Patent Publication No. 2002-305839

The embodiment provides a method for inspecting a power conversion device that can easily inspect the presence or absence of an abnormality in an optical turnout that branches an optical fiber.

In the embodiment, a first terminal, a second terminal to which a voltage higher than that of the first terminal can be input, a plurality of thyristors connected in series between the first terminal and the second terminal, and the above-mentioned It is provided so as to detect the voltage across each of the plurality of thyristors, and when any one of the plurality of thyristors is turned on, a logical value of 0 is output according to the one of the thyristors, and any of the above. The number of the plurality of thyristors of the first gate signal consisting of a plurality of voltage detectors that output a logic value 1 according to any of the thyristors when the thyristor is off and an optical signal transmitted by the first optical fiber. A power converter comprising an optical branching device that branches into the second gate signal of the minute and a plurality of second optical fibers connected to the optical branching device and supplying the second gate signal to the plurality of thyristors. This is an inspection method for a power conversion device including a gate control device that generates the first gate signal and supplies the first optical fiber. In this inspection method, a DC voltage is applied between the first terminal and the second terminal, the first gate signal having a logical value of 1 is transmitted from the transmission end of the first optical fiber, and the plurality of voltages are transmitted. A plurality of logical values output from the detector are logically calculated, and based on the calculation results of the plurality of logical values, the first optical fiber, the optical brancher, or the plurality of second optical fibers is defective. It is determined that there is.

In the present embodiment, a method for inspecting a power conversion device that can easily inspect the presence or absence of an abnormality in an optical turnout that branches an optical fiber is realized.

It is a schematic block diagram which illustrates the power conversion apparatus which concerns on embodiment. It is a schematic block diagram which illustrates a part of the power conversion apparatus of an embodiment. It is an example of the flowchart for demonstrating the inspection method of the power conversion apparatus of embodiment. It is a schematic block diagram which illustrates a part of the power conversion apparatus of the comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio of the sizes between the parts, and the like are not always the same as the actual ones. Further, even when the same part is represented, the dimensions and ratios may be different from each other depending on the drawing.
In addition, in the present specification and each figure, the same elements as those described above with respect to the above-mentioned figures are designated by the same reference numerals, and detailed description thereof will be omitted as appropriate.

FIG. 1 is a schematic block diagram illustrating the power conversion device according to the embodiment.
As shown in FIG. 1, the power converter of the embodiment includes a power converter 12 and a gate control device 20. The power converter 12 and the gate control device 20 are connected to each other.

The power converter 12 includes terminals 13a to 13c and terminals 13d and 13e. The power converter 12 is connected to the AC circuit 1000 via the terminals 13a to 13c. The AC circuit 1000 is, for example, an AC power system including an AC power supply, an AC transmission line, and the like.

The power converter 12 is connected to the DC circuit 1002 via the terminals 13d and 13e. The DC circuit 1002 is a DC power system including, for example, a DC power supply, a DC transmission line, or the like.

The power converter 12 performs phase control according to the gate signals G1 to G6 transmitted from the gate control device 20, and converts AC power into DC power, or converts DC power into AC power. The power conversion between AC and DC may be bidirectional or unidirectional.

In this example, the power conversion device 1 also includes a control panel 30, and the control panel 30 transmits and receives various signals to and from the gate control device 20 to control and monitor the power conversion by the power converter 12. ..

The power converter 12 includes a thyristor valve 10. In this example, the power converter 12 includes a 6-phase thyristor valve 10. The thyristor valve 10 is not limited to 6 phases, but may be 12 phases or the like. Gate signals G1 to G6 having different phases for each phase are supplied to the thyristor valve 10. Each thyristor valve 10 performs a phase control operation according to the gate signals G1 to G6.

The thyristor valve 10 generates FV signals FV1 to FV6 and transmits them to the gate control device 20. The FV signal is a signal for determining whether or not the thyristor constituting the thyristor valve 10 is normally turned on. Therefore, the FV signal is generated for each thyristor. For example, in the thyristor valve 10 that receives the gate signal G1 and controls the phase, m thyristors generate FV signals FV11 to FV1m and transmit them to the gate control device 20.

The thyristor valve 10 includes a plurality of thyristors. Multiple thyristors are connected in series to achieve the required withstand voltage. Therefore, a plurality of thyristors connected in series in one thyristor valve 10 are ignited by a gate signal having the same phase.

In the inspection method of the power conversion device of the present embodiment, the logical operation of the FV signal generated for the thyristor to which the gate signal of the same phase is input is performed, and the presence or absence of the abnormality of the optical splitter is determined based on the logical operation result. ..

FIG. 2 is a schematic block diagram illustrating a part of the power conversion device of the embodiment.
FIG. 2 shows a more detailed configuration example for realizing the inspection method of the power conversion device of the embodiment, and shows a part of the thyristor valve 10.
As shown in FIG. 2, the thyristor valve 10 includes a plurality of thyristor valve modules 100 as in this example. A plurality of thyristor valve modules 100 are connected in series. The number of series of thyristor valves 10 is determined by the withstand voltage of the thyristor valve module 100 and the voltage handled by the power converter 12, and depending on these, the thyristor valve 10 may include one thyristor valve module 100.

Since the plurality of thyristor valve modules 100 have the same configuration, one thyristor valve module 100 illustrated will be described.
The thyristor valve module 100 includes a plurality of thyristors 102. The plurality of thyristors 102 are connected in series. In this example, n thyristors 102 are connected in series. The number n of the thyristors 102 can be arbitrarily set, but in the present embodiment, it is preferable to match the number n with the number of branches of the optical splitter 106 in order to determine whether or not there is an abnormality in the optical splitter 106.

The series circuit of the thyristor 102 is connected between the terminals 101p and 101n. The terminal 101p (second terminal) is a terminal on the high potential side, and the terminal 101n (first terminal) is a terminal on the low potential side. The thyristor valve module 100 is connected to another thyristor valve module 100 via terminals 101p and 101n.

The thyristor 102 is preferably an optical thyristor. By using the optical thyristor, the gate drive circuit can be simplified and the thyristor valve module 100 can be downsized.

The terminals 101p and 101n are used not only for connecting the thyristor valve modules 100 to each other, but also as terminals for connecting a DC power supply when the inspection method of the embodiment is carried out.

A voltage detector 104 is connected to each of the plurality of thyristors 102. The voltage detector 104 is connected so as to detect the voltage between the anode and the cathode of the thyristor 102. The voltage detector 104 produces an FV signal. The FV signal is a logic signal, is generated as an optical signal, and is output. The voltage detector 104 generates and outputs a logical value “0” (or low level) as an FV signal when the anode-cathode voltage of the thyristor 102 is at the voltage level (low voltage) in the ON state. When the anode-cathode voltage of the thyristor 102 is at the voltage level (high voltage) in the off state, the voltage detector 104 generates and outputs a logical value “1” (or high level) as an FV signal.

The voltage detector 104 is configured to have a path for passing a latching current so that even if some of the thyristors 102 connected in series do not turn on, the other thyristors 102 turn on. It is assumed that it has been done.

Each voltage detector 104 is connected to the determination circuit 24. The voltage detector 104 supplies the generated FV signal to the determination circuit 24.

The determination circuit 24 is built in, for example, the gate control device 20. The connection between the voltage detector 104 and the determination circuit 24 is made by, for example, an optical fiber. The determination circuit 24 may be provided in the power converter 12. Further, the determination circuit 24 may be housed in a housing separate from the power converter 12 and the gate control device 20 so as to be connected to the thyristor valve module 100 when performing the inspection method of the embodiment. good.

The thyristor bulb module 100 includes an optical splitter 106. The optical splitter 106 branches one optical fiber into a plurality of optical fibers. The optical splitter 106 may be a waveguide type or an optical fiber coupler. In this example, the number of branches is n, and one optical fiber is branched into n lines, and one optical signal is distributed to the gates of n thyristors 102. In this embodiment, since the gate control device 20 side is a dual system, two optical signals are input. The two input optical signals are the same signal and are merged into one optical signal in the optical splitter 106. The merged optical signal is further branched into n optical fibers 108 (second optical fiber).

The optical splitter 106 is connected to the optical signal output circuit 22 via optical fibers 26A and 26B (first and third optical fibers). Although not shown, another thyristor bulb module 100 connected in series to the thyristor bulb module 100 also has an optical splitter connected to the optical signal output circuit 22 via optical fibers 26C and 26D.

In this example, the four optical fibers 26A to 26D are a four-core collective optical fiber cable 26. By using a multi-core collective optical fiber cable, the construction method at the time of laying the optical fiber can be simplified, the working time can be shortened, the cost can be reduced, and the like.

The optical signal output circuit 22 includes a plurality of light emitting elements LD_A to LD_D. The plurality of light emitting elements LD_A to LD_D are, for example, laser diodes. The light emitting element LD_A is connected to the transmission end of the optical fiber 26A. The light emitting element LD_B is connected to the transmission end of the optical fiber 26B. That is, the optical signal output by the light emitting element LD_A is input to the optical splitter 106 via the optical fiber 26A. The optical signal output by the light emitting element LD_B is input to the optical splitter 106 via the optical fiber 26B.

The optical signal output circuit 22 is built in, for example, the gate control device 20. In that case, the gate control device 20 includes a test mode, and when the test mode is set, the light emitting elements LD_A to LD_D can be made to emit light at a predetermined timing or the like. The predetermined timing is, for example, the timing at which the light emitting elements LD_A to LD_D simultaneously emit light. A predetermined timing may be a timing for sequentially causing the light emitting elements to emit light, or a timing for simultaneously lighting the light emitting elements for each thyristor bulb module 100. In this example, since the optical fibers 26A and 26B form a dual transmission line, the light emitting elements LD_A and LD_B emit light at the same time regardless of whether or not they are in the test mode, and the light has the same phase. It is assumed that signals (first gate signal, third gate signal) are output.

As described above, the optical signal output circuit 22 and the determination circuit 24 can be provided at any location. The optical signal output circuit 22 and the determination circuit 24 can be realized by using software for operating circuit elements, programs, and the like already installed in the gate control device 20 and the control panel 30. Therefore, when it is provided in the gate control device 20 or the control panel 30, it can be introduced by adding or modifying a part of the existing software.

An inspection method of the power conversion device of the embodiment will be described.
FIG. 3 is an example of a flowchart for explaining an inspection method of the power conversion device of the embodiment.
Each step of the flowchart of FIG. 3 is executed in the determination circuit 24 in this embodiment. The determination circuit 24 acquires n FV signals FV1 to FVn from the n voltage detectors 104 in the thyristor valve module 100. The determination circuit 24 logically operates n FV signals to determine whether all the gate signals are received on the power converter 12 side, or whether some or all of the gate signals are not delivered. If part or all of the gate signal is not reached, the determination circuit 24 determines whether the cause is the optical splitter 106 and the optical fiber cable 26, or the optical fiber 108 in the thyristor valve module 100. It can be determined.

In executing the flowchart of FIG. 3, a DC voltage is applied between the terminals 101p and 101n of the thyristor valve module 100. For example, by connecting a DC power supply between the terminals 101p and 101n, a DC voltage is applied to both ends of the thyristor valve module 100. Of course, other methods may be used as long as an appropriate value of DC voltage can be applied to both ends of the thyristor valve module 100.

As shown in FIG. 3, in step S1, the optical signal output circuit 22 sets the gate signal GP to the logic value “1” and causes the light emitting elements LD_A to LD_D to emit light.

In the block diagram of FIG. 2, when there is no defect in the transmission path of the optical signal, the thyristor bulb module 100 operates as follows.
The optical signal (first gate signal) output by the light emitting element LD_A reaches the optical splitter 106 through the optical fiber 26A. The optical splitter 106 branches the transmitted optical signal into n optical fibers 108 to obtain n optical signals (second gate signals). When the optical signal reaches the gate of the thyristor 102 via the optical fiber 108, the thyristor 102 turns on. When the thyristor 102 is turned on, the anode-cathode voltage of the thyristor 102 is lowered, the voltage detector 104 is turned off, and the FV signal outputs the logic value “0”.

The operation of the thyristor valve module 100 when there is a defect in the transmission path of the optical signal and the transmission of the optical signal is hindered is as follows.
The optical signal output by the light emitting element LD_A cannot reach the gate of the thyristor 102 because it causes transmission failure to reach any of the optical fiber 26A, the optical splitter 106, and the optical fiber 108. Therefore, the thyristor 102 is in the off state, the voltage detector 104 remains in the on state, and outputs an FV signal having a logic value of “1”.

As described below, the determination circuit 24 can determine whether all of the n FV signals FV1 to FVn are undeliverable or some of them are undeliverable, and output the determination result. ..

In step S2, the determination circuit 24 acquires n FV signals FV1 to FVn. The determination circuit 24 calculates the logical product (AND) of n FV signals FV1 to FVn. When the result of the operation of the logical product is the logical value "1", the determination circuit 24 shifts the process to step S3. When the result of the operation of the logical product is the logical value "0", the determination circuit 24 shifts the process to step S4. The fact that the operation result of the logical product is "1" means that all the FV signals FV1 to FVn have the logical value "1". When the logical value of all FV signals FV1 to FVn is "1", it means that all thyristors 102 cannot be turned on.

In step S3, the determination circuit 24 determines that there is a defect in the optical signal transmission path. The problem in this case is determined to be either the optical fiber cable 26 or the optical splitter 106 because all thyristors 102 cannot turn on. In this embodiment, since the control side is a dual system, the light emitting elements LD_A and LD_B are driven so as to emit light at the same time. Therefore, the place where the non-delivery factor occurs in the transmission path before the optical splitter 106 is the case where both the optical fibers 26A and 26B simultaneously cause the non-delivery factor. In order for a plurality of optical fibers to become a non-delivery factor, the factor is presumed to be, for example, the location of the 4-core collective optical fiber cable 26.

In step S4, the determination circuit 24 performs a logical operation using the acquired n FV signals FV1 to FVn. The determination circuit 24 calculates the logical sum (OR) of n FV signals FV1 to FVn. When the calculation result of the logical sum is the logical value "1", the determination circuit 24 shifts the process to step S5. When the calculation result of the logical sum is the logical value "0", the determination circuit 24 shifts the process to step S6.

The fact that the calculation result of the logical sum of the FV signals is the logical value "1" indicates that there is a thyristor 102 that cannot be turned on among the thyristors 102 connected in series. If the thyristor cannot be turned on, the thyristor itself may be defective. However, in the present embodiment, the thyristor 102 is housed in, for example, a pressure welding type package, and when the thyristor 102 fails, it fails in the short-circuit mode. do. That is, when the thyristor 102 is out of order, the voltage detector 104 connected to the thyristor 102 outputs an FV signal having a logic value of "0" regardless of the logic value of the gate signal GP. .. Such a defect can be determined by the FV signal when the logical value of the gate signal GP is “0”.

In step S5, the determination circuit 24 determines that there is a defect in the optical signal transmission path. From the determination result in step S2, since there is no defect in the transmission path to the optical splitter 106, it is determined that the defect in this case is one of the optical fibers 108 in the thyristor valve module 100.

In step S6, the determination circuit 24 determines that there is no problem in the transmission path of the optical signal.

The determination result of the determination circuit 24 may be, for example, to turn on the lamp of the emission color corresponding to each of steps S3, S5, S6, or a display device may be separately provided to describe the contents of steps S3, S5, S6. The text or the like may be displayed.

In this way, in the inspection method of the power conversion device of the embodiment, it is possible to inspect whether or not there is a defect in the transmission path of the optical signal, and if there is a defect, it is possible to determine the defective portion.

The effect of the inspection method of the power conversion device of the embodiment will be described.
FIG. 4 is a schematic block diagram illustrating a power conversion device of a comparative example.
As shown in FIG. 4, the power conversion device of the comparative example includes the thyristor valve module 200. The thyristor valve module 200 includes a thyristor 102 connected in series, and an optical fiber 228A or the like is connected to the gate of each thyristor 102. The optical fiber 228A and the like are formed so that double redundant optical signals merge, and the two optical signals are transmitted via the two optical fibers 226A, 226B and the like. The optical fibers 226A and 226B are connected to the optical fiber 228A by the optical connectors 227A and 227B.

In the power conversion device of the comparative example, the gate of each thyristor 102 is thus connected to the optical signal output circuit 22 via an optical fiber. When the installation location of the gate control device having the optical signal output circuit 22 and the installation location of the power converter having the thyristor valve module 200 are separated, a large number of optical fibers are used according to the number of thyristors 102. Fiber 226A or the like needs to be laid.

In the power conversion device 1 of the embodiment, the optical signal (gate pulse) transmitted via the optical fiber is branched and distributed for each thyristor 102 by the optical splitter 106 provided in the power converter 12. Therefore, the number of long optical fibers can be reduced according to the number of optical splitters 106 installed.

On the other hand, by adding the optical splitter 106 in the power converter 12, it is necessary to additionally inspect the presence or absence of abnormality in the optical splitter 106. If the optical splitter 106 and the optical fiber are removed and inspected each time the power converter 12 is installed or in the periodic or irregular inspection of the power converter 12, the inspection time becomes long and the inspection becomes costly. An increase is inevitable.

Therefore, in the present embodiment, by logically operating the FV signals FV1 to FVn in the determination circuit 24, it becomes possible to easily inspect the presence or absence of a defect in the transmission path including the optical splitter 106.

According to the present embodiment, the output of the determination circuit 24 is not limited to inspecting the presence or absence of a defect in the transmission path, and it is possible to determine where the defect is in the transmission path. Time can be shortened.

According to the embodiment described above, it is possible to realize a method for inspecting a power conversion device that can easily inspect the presence or absence of an abnormality in an optical turnout that branches an optical fiber.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention and its equivalents described in the claims. In addition, each of the above-described embodiments can be implemented in combination with each other.

1 power converter, 10 thyristor valve, 12 power converter, 20 gate control device, 22 optical signal output circuit, 24 judgment circuit, 26 optical fiber, 30 control panel, 100 thyristor valve module, 101p, 101n terminal, 102 thyristor, 104 voltage detector, 106 optical splitter, 108 optical fiber

Claims (5)

1st terminal and
A second terminal to which a voltage higher than that of the first terminal can be input, and
A plurality of thyristors connected in series between the first terminal and the second terminal,
It is provided so as to detect the voltage across each of the plurality of thyristors, and when any one of the plurality of thyristors is turned on, a logical value of 0 is output according to the one of the thyristors, and any of the above. Multiple voltage detectors that output a logical value of 1 according to any of the above thyristors when the thyristor is off.
An optical turnout that branches a first gate signal consisting of an optical signal transmitted by the first optical fiber into a second gate signal corresponding to the number of the plurality of thyristors.
A plurality of second optical fibers connected to the optical turnout and supplying the second gate signal to the plurality of thyristors.
With power converters, including
A gate control device that generates the first gate signal and supplies it to the first optical fiber,
It is an inspection method of a power conversion device equipped with
A DC voltage is applied between the first terminal and the second terminal,
The first gate signal having a logic value of 1 is transmitted from the transmission end of the first optical fiber.
A plurality of logical values output from the plurality of voltage detectors are logically operated to perform a logical operation.
A method for inspecting a power conversion device for determining that one of the first optical fiber, the optical turnout, or the plurality of second optical fibers has a defect based on the calculation result of the plurality of logical values. It is possible to perform a logical operation on a plurality of logical values output from the plurality of voltage detectors.
Including computing the logical product of the plurality of logical values
The method for inspecting a power conversion device according to claim 1, wherein when the calculation result of the logical product of the plurality of logical values is the logical value 1, it is determined that there is a defect in either the first optical fiber or the optical turnout. It is possible to perform a logical operation on a plurality of logical values output from the plurality of voltage detectors.
Including the operation of the logical sum of the plurality of logical values.
The operation result of the logical product of the plurality of logical values is the logical value 0, and
The method for inspecting a power conversion device according to claim 2, wherein when the calculation result of the logical sum of the plurality of logical values is the logical value 1, it is determined that there is a defect in any of the plurality of second optical fibers. The optical branching device is connected to a third optical fiber, and the optical signal transmitted by the third optical fiber is branched into optical signals corresponding to the number of the plurality of thyristers by the second optical fiber.
The gate control device supplies the first gate signal to the first optical fiber, and supplies a third gate signal having the same phase as the first gate signal to the third optical fiber.
The first aspect of claim 1, wherein it is determined that there is a defect in any of the first optical fiber, the optical branching device, the plurality of second optical fibers, and the third optical fiber based on the calculation results based on the plurality of logical values. How to inspect the power converter. The method for inspecting a power conversion device according to claim 4, wherein the first optical fiber and the third optical fiber form an collective optical fiber cable.

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