JP2022007579A - Control device - Google Patents

Abstract

To provide a control device for a separately excited power converter capable of more stably performing a bypass pair operation even when a control circuit and a drive circuit are made redundant.SOLUTION: A control device comprises a plurality of control circuits for generating control signals for controlling conduction of a plurality of switch parts of a separately excited power converter, and a plurality of drive circuits for generating driving pulses for making the plurality of switch parts conductive based on the control signals input from any of the plurality of control circuits. When a bypass pair command is input, the plurality of control circuits select the switch part of a conduction phase based on the last output control signal, select the switch part for performing the bypass pair operation based on the switch part of the conduction phase, input the control signal for the switch part for performing the bypass pair operation to the plurality of drive circuits, and, in a normal operation, set a selection inhibition period during which the selection of the switch part of the conduction phase is inhibited during a predetermined period from a timing of the output of the control signal.SELECTED DRAWING: Figure 3

Description

Embodiments of the present invention relate to a control device.

There is a power conversion device including a separately-excited power converter using a separately-excited switching element such as a thyristor, and a control device for controlling the operation of the separately-excited power converter. The power conversion device is used in, for example, a power conversion system that converts AC power into DC power and returns the DC power to AC power.

The power conversion system is, for example, a direct current transmission (HVDC: High Voltage Direct Current) that transmits power by direct current power, a frequency converter (FC: Frequency Converter) that converts frequency, or two alternating currents without frequency conversion. It is used for BTB (Back-To-Back) that interconnects power systems.

The control device has a control circuit and a drive circuit. The control circuit inputs a control signal for controlling the firing of the separately excited switching element to the drive circuit. The drive circuit generates a drive pulse that ignites the separately excited switching element based on the input control signal, and inputs the drive pulse to the separately excited power converter. As a result, the control device controls the conversion of electric power by the separately excited power converter.

In such a control device, the control circuit and the drive circuit are made redundant. For example, two control circuits input control signals to each of the two drive circuits. The two drive circuits generate drive pulses based on control signals input from at least one of the two control circuits. Then, each of the two drive circuits inputs a drive pulse to the separately excited power converter. As a result, even if one control circuit and drive circuit breaks down, the operation can be continued by the other control circuit and drive circuit, and the operation continuity of the power conversion device can be improved.

However, in a control device in which the control circuit and the drive circuit are made redundant in this way, a bypass pair (hereinafter, "" In some cases, the operation of "BPP") could not be performed normally.

The control device performs a BPP operation when the power conversion system is stopped, or when an abnormality is detected in the power conversion system and protection is stopped. This makes it possible to disconnect the DC circuit and the AC circuit. In order to smoothly commutate to the BPP phase during BPP operation, it is necessary to select an appropriate BPP phase for the current conduction phase. At this time, in the redundant control device, different BPP phases may be selected among a plurality of control circuits due to timing deviation or the like. In the drive circuit, the control signal for BPP operation is selected on a first-come, first-served basis. Therefore, in the drive circuit, there is a possibility that the control signal of the BPP operation output from any control circuit is also selected. As a result, a selection state such as selecting a different BPP phase among a plurality of drive circuits occurs. For example, a drive pulse may be output to four phases, a UX phase and a VY phase, for a six-phase thyristor bridge.

Therefore, in the control device that controls the operation of the separately excited power converter, it is desired that the BPP operation can be performed more stably even when the control circuit and the drive circuit are made redundant.

Japanese Unexamined Patent Publication No. 4-150776 Japanese Unexamined Patent Publication No. 5-49162

The embodiment provides a control device for a separately excited power converter capable of more stably performing a bypass pair operation even when the control circuit and the drive circuit are made redundant.

The control device according to the embodiment is a control device that controls power conversion by a separately excited power converter having a plurality of bridge-connected switch portions, and is a control signal for controlling conduction of the plurality of switch portions. Based on the plurality of control circuits that generate A plurality of drive circuits to be input to the unit are provided, and operation can be continued by any one of the plurality of control circuits and any one of the plurality of drive circuits. When a bypass pair command is input to instruct the execution of a bypass pair operation that makes the high-voltage side switch section and the low-voltage side switch section connected to the same phase of multiple switch sections in a conductive state at the same time. Based on the control signal output last, the switch unit of the conduction phase among the plurality of switch units is selected, and the switch unit that performs the bypass pair operation is selected based on the switch unit of the conduction phase. In the normal operation of inputting the control signal to the switch unit performing the bypass pair operation to the plurality of drive circuits and controlling the power conversion by the separately excited power converter, the output timing of the control signal is performed. The period from 1 to 2 is set as a selection prohibition period for prohibiting selection of the switch portion of the conduction phase even when the bypass pair command is input.

In the present embodiment, there is provided a control device for a separately excited power converter that can perform bypass pair operation more stably even when the control circuit and the drive circuit are made redundant.

It is a block diagram schematically showing the power conversion system which concerns on 1st Embodiment. It is a block diagram schematically showing the 1st power conversion apparatus which concerns on 1st Embodiment. It is a timing chart schematically showing an example of the operation of the 1st control device which concerns on 1st Embodiment. It is a block diagram schematically showing the 1st power conversion apparatus which concerns on 2nd Embodiment. It is a timing chart schematically showing an example of the operation of the 1st control device which concerns on 2nd Embodiment. It is a block diagram schematically showing the 1st control apparatus which concerns on 3rd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
It should be noted that 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 necessarily 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.

(First Embodiment)
FIG. 1 is a block diagram schematically showing a power conversion system according to the first embodiment.
As shown in FIG. 1, the power conversion system 10 includes a first power conversion device 11 (power conversion device), a second power conversion device 12 (power conversion device), and a DC circuit 14. The first power converter 11 includes a first separately excited power converter 21 (other-excited power converter) and a first control device 31 (control device). The second power converter 12 includes a second separately excited power converter 22 (other-excited power converter) and a second control device 32 (control device).

The DC circuit 14 is provided between the first power conversion device 11 and the second power conversion device 12. More specifically, the DC circuit 14 is provided between the first separately excited power converter 21 and the second separately excited power converter 22. The DC circuit 14 connects the first separately excited power converter 21 and the second separately excited power converter 22.

The first separately excited power converter 21 is connected to the first AC power system 2a and the DC circuit 14. The second separately excited power converter 22 is connected to the second AC power system 2b and the DC circuit 14. That is, the first separately excited power converter 21 and the second separately excited power converter 22 are connected to each other via the DC circuit 14.

The first separately excited power converter 21 converts the AC power supplied from the first AC power system 2a into DC power, and supplies the DC power to the DC circuit 14. The second separately excited power converter 22 converts the DC power supplied from the DC circuit 14 into AC power, and supplies the AC power to the second AC power system 2b.

The AC power of each AC power system 2a and 2b is, for example, three-phase AC power. The separately excited power converters 21 and 22 perform, for example, conversion from three-phase AC power to DC power and conversion from DC power to three-phase AC power. The AC power of each AC power system 2a and 2b may be single-phase AC power or the like.

In this way, the power conversion system 10 converts the AC power of the first AC power system 2a into DC power, returns it to AC power again, and supplies it to the second AC power system 2b. Further, in the power conversion system 10, contrary to the above, power can be supplied from the second AC power system 2b side to the first AC power system 2a side. In other words, the power conversion system 10 interconnects the AC power systems 2a and 2b via the separately excited power converters 21 and 22. However, the direction of supplying power is only one direction from the first separately excited power converter 21 to the second separately excited power converter 22 or from the second separately excited power converter 22 to the first separately excited power converter 21. But it may be.

The DC circuit 14 has a positive DC bus 14p, a negative DC bus 14n, a DC reactor 14x, and a DC reactor 14y. The DC reactor 14x and the DC reactor 14y are provided on the positive DC bus 14p.

The power conversion system 10 is used, for example, for DC power transmission. In this case, the positive DC bus 14p is a DC cable such as a submarine cable. The negative DC bus 14n may be a cable return route, a ground return route, a seawater return route, or the like. That is, the negative DC bus 14n is provided as needed and can be omitted. The DC reactors 14x and 14y are provided, for example, on the positive DC bus 14p and suppress the harmonics of the current flowing through the positive DC bus 14p (DC circuit 14).

The power conversion system 10 includes a frequency converter, BTB, etc. that directly connects the DC side of the first separately excited power converter 21 and the DC side of the second separately excited power converter 22 without using a power transmission cable or the like. But it may be. In this case, for example, the wiring member such as a bus bar connecting the DC side of the first separately excited power converter 21 and the DC side of the second separately excited power converter 22 may be the DC circuit 14. In this case, either the DC reactor 14x or 14y can be omitted. Either the DC reactor 14x or 14y may be provided in the DC circuit 14 as needed.

The first control device 31 is connected to the first separately excited power converter 21 via a signal line 41. The first control device 31 controls the conversion of electric power by the first separately excited power converter 21. The first separately excited power converter 21 has, for example, a plurality of bridge-connected switch units. Each switch unit has a separately excited switching element. The first control device 31 is connected to each switch unit of the first separately excited power converter 21 via, for example, a signal line 41, and is provided in each switch unit by inputting a drive pulse to each switch unit. Controls the on-timing of the switching element. In this way, the first control device 31 controls the power conversion by the first separately excited power converter 21 by controlling the on-timing of the switching element of each switch portion of the first separately excited power converter 21. ..

Further, the first control device 31 acquires various data (feedback values) required for control from the first separately excited power converter 21. The first control device 31 measures, for example, the AC voltage value of each phase of the first AC power system 2a, the DC voltage value of the DC circuit 14, the DC current value of the DC circuit 14, and the like in the power conversion system 10. Get from.

The second control device 32 is connected to the second separately excited power converter 22 via the signal line 42. Similar to the first control device 31, the second control device 32 acquires various data from the second separately excited power converter 22, and the on-timing of the switching element of each switch portion of the second separately excited power converter 22. By controlling the above, the conversion of electric power by the second separately excited power converter 22 is controlled.

The first control device 31 and the second control device 32 are connected to each other via a network 44 or the like. The first control device 31 and the second control device 32 coordinately control the operations of the first separately excited power converter 21 and the second separately excited power converter 22 by communicating with each other. The first control device 31 and the second control device 32 coordinate with each other to convert the first separately excited power when, for example, the first separately excited power converter 21 or the second separately excited power converter 22 fails. The device 21 and the second separately excited power converter 22 are protected and stopped.

The configuration of the second power conversion device 12 can be substantially the same as the configuration of the first power conversion device 11. Therefore, in the following, the configuration of the first power conversion device 11 will be described, and the description of the configuration of the second power conversion device 12 will be omitted. In the power conversion system 10, the configuration of the second power conversion device 12 does not necessarily have to be the same as the configuration of the first power conversion device 11. The configuration of the second power conversion device 12 may differ from the configuration of the first power conversion device 11 to the extent that the operation of the power conversion system 10 can be realized.

FIG. 2 is a block diagram schematically showing a first power conversion device according to the first embodiment.
As shown in FIG. 2, the first separately excited power converter 21 of the first power converter 11 has six switch portions 51u, 51v, 51w, 51x, 51y, 51z connected by a three-phase bridge. Hereinafter, for convenience, when the switch units 51u, 51v, 51w, 51x, 51y, and 51z are collectively referred to, they are referred to as "switch unit 51". In the following, the switch unit 51u is referred to as a U phase, the switch portion 51v is referred to as a V phase, the switch portion 51w is referred to as a W phase, the switch portion 51x is referred to as an X phase, the switch portion 51y is referred to as a Y phase, and the switch portion 51z is referred to as a Z phase. There is also.

Each switch unit 51 has a separately excited switching element 51s. For the switching element 51s, for example, a thyristor or the like is used. The switch unit 51 has, for example, a plurality of switching elements 51s connected in series. Each switch section 51 is, for example, a thyristor valve. In this example, the first separately excited power converter 21 is a 6-phase thyristor bridge. However, the first separately excited power converter 21 is not limited to this, and may be, for example, a 12-phase thyristor bridge or the like.

The first control device 31 includes a first control circuit 61, a second control circuit 62, a first drive circuit 71, and a second drive circuit 72. The first control circuit 61 and the second control circuit 62 generate a control signal for controlling the continuity of the plurality of switch units 51 provided in the first separately excited power converter 21, and the generated control signal is first. Input to each of the drive circuit 71 and the second drive circuit 72. In other words, the first control circuit 61 and the second control circuit 62 are control signals for controlling the firing of the separately excited switching element 51s provided in each switch portion 51 of the first separately excited power converter 21. To generate. The control signal is, for example, a pulsed signal. The control signal may also be called a phase control pulse or the like.

The first control circuit 61 and the second control circuit 62 control the on-timing of each switch unit 51 based on, for example, the voltage phase of the AC voltage of the first AC power system 2a. In the normal operation of controlling the power conversion by the first separately excited power converter 21, the first control circuit 61 and the second control circuit 62 are switched, for example, based on the voltage phase of the first AC power system 2a. Each switch unit 51 is made conductive in the order of 51u → switch unit 51z → switch unit 51v → switch unit 51x → switch unit 51w → switch unit 51y, and a control signal is generated so as to repeat this. Further, the on-timing of each switch unit 51 is also referred to as a control angle. The first control circuit 61 and the second control circuit 62 control the voltage value of the DC voltage or the current value of the DC current applied to the DC circuit 14 by controlling the control angle of each switch unit 51.

The first drive circuit 71 and the second drive circuit 72 are connected to each switch unit 51 via a signal line 41, respectively. The first drive circuit 71 and the second drive circuit 72 generate a drive pulse for conducting each switch unit 51 based on the control signal input from either the first control circuit 61 or the second control circuit 62. The drive pulse is input to each switch unit 51. As a result, the first control device 31 controls the conversion of electric power by the first separately excited power converter 21.

The signal line 41 is, for example, an optical fiber cable. As a result, the first separately excited power converter 21 and the first control device 31 can be electrically isolated. The drive pulse generated by the first drive circuit 71 and the second drive circuit 72 is, for example, an optical signal. The signal line 41 has, for example, a two-branch light guide 41a, and inputs drive pulses output from each of the first drive circuit 71 and the second drive circuit 72 to each switch unit 51.

The first drive circuit 71 and the second drive circuit 72 receive, for example, control signals input from each of the first control circuit 61 and the second control circuit 62 in the OR circuit. As a result, the first drive circuit 71 and the second drive circuit 72 generate a drive pulse based on the control signal input from at least one of the first control circuit 61 and the second control circuit 62.

Each switch unit 51 receives drive pulses input from each of the first drive circuit 71 and the second drive circuit 72 in the OR circuit. As a result, each switch unit 51 ignites based on the drive pulse input from at least one of the first drive circuit 71 and the second drive circuit 72.

As described above, in the first control device 31, the control circuit and the drive circuit are duplicated. As a result, even if one control circuit and drive circuit breaks down, the operation can be continued by the other control circuit and drive circuit, and the operation continuity of the first power conversion device 11 can be improved. Can be done.

In this example, two control circuits 61 and 62 and two drive circuits 71 and 72 are shown, but the number of control circuits and the number of drive circuits provided in the first control device 31 are the same. The number is not limited to three or more. Further, the number of drive circuits does not necessarily have to be the same as the number of control circuits. The number of drive circuits may be different from the number of control circuits.

The first control circuit 61 and the second control circuit 62 are connected to the host device 4. The higher-level device 4 is, for example, a higher-level controller of the first control device 31 such as an operation control device or a protection device. The host device 4 has the same phase of the plurality of switch units 51 when the power conversion system 10 is stopped, or when an abnormality in the power conversion system 10 is detected and the power conversion system 10 is protected and stopped. A BPP command instructing the execution of the BPP operation in which the high-voltage side switch unit 51 and the low-voltage side switch unit 51 connected to the above are simultaneously in a conductive state is input to the first control device 31. The BPP command is not limited to the higher-level device 4, and may be input to the first control device 31 according to the operation of the operation panel by the operator, for example, or the detected value of the current or voltage of each part. It may be generated in the first control device 31 based on.

The first control device 31 inputs a BPP command to each of the first control circuit 61 and the second control circuit 62. In the first control circuit 61 and the second control circuit 62, the BPP operation in which the high-voltage side switch section 51 and the low-voltage side switch section 51, which are connected to the same phase by the BPP command in response to an input, are simultaneously made conductive. To execute.

In the case of BPP operation, the first control circuit 61 and the second control circuit 62 select the next switch section 51 next to the switch section 51 of the conduction phase as the BPP phase in the normal operation, and control the switch section 51 to conduct the switch section 51. The operation of inputting a signal to the first drive circuit 71 and the second drive circuit 72 is performed. The switch unit 51 of the conduction phase is, in other words, the switch unit 51 that was finally conducted. The first control circuit 61 and the second control circuit 62 select the switch portion 51 of the conduction phase based on the control signal output last.

For example, when the switch unit 51 of the conduction phase is the switch unit 51u, the next next switch unit 51v is selected as the BPP phase, and the switch unit 51v is made conductive. As a result, the BPP operation can be performed by the VY phase of the switch unit 51v and the switch unit 51y. In this way, by including the conducting phase in the BPP phase, commutation for performing the BPP operation can be smoothly performed. The above is an example of selecting the phase of the control signal output second from the last as the BPP phase, but the present invention is not limited to this, and the phase of the control signal output last may be selected as the BPP phase. ..

The first drive circuit 71 and the second drive circuit 72 receive the control signal of the BPP operation on a first-come, first-served basis. That is, in the first drive circuit 71 and the second drive circuit 72, regarding the control signal of the BPP operation, only the control signal of the BPP operation input first from either the first control circuit 61 or the second control circuit 62. To receive. The first drive circuit 71 and the second drive circuit 72 generate a drive pulse based on the received control signal of the BPP operation, and input the drive pulse to the corresponding switch unit 51 to BPP the first separately excited power converter 21. Put it in a working state.

FIG. 3 is a timing chart schematically showing an example of the operation of the first control device according to the first embodiment.
As described above, the first control circuit 61 and the second control circuit 62 select the switch portion 51 of the conduction phase based on the last output control signal when the BPP command is input. At this time, as shown in FIG. 3, in the normal operation, the first control circuit 61 and the second control circuit 62 also receive a BPP command for a predetermined period from the output timing of the control signal. The selection prohibition period is set to prohibit the selection of the switch portion 51 of the conduction phase.

As shown in FIG. 3, the output timing of the control signal of the first control circuit 61 is the control signal of the second control circuit 62 due to a synchronization deviation between the first control circuit 61 and the second control circuit 62 or the like. It may be different from the output timing of.

When the selection prohibition period is not set as described above and the BPP command is input in the period in which the output timing of the control signal is deviated as shown in FIG. 3, the first control circuit 61 and the first control circuit 61 2 A different BPP phase is selected in the control circuit 62. For example, in the example shown in FIG. 3, the first control circuit 61 selects the switch section 51u (U phase) as the conduction phase, whereas the second control circuit 62 conducts the switch section 51z (Z phase). Select as a phase. As a result, the first control circuit 61 selects the switch unit 51v (V phase), and the second control circuit 62 selects the switch unit 51x (X phase) as the BPP phase.

As described above, the first drive circuit 71 and the second drive circuit 72 receive the BPP operation control signal on a first-come, first-served basis. Therefore, when the control signals of different BPP operations from the first control circuit 61 and the second control circuit 62 are input to the first drive circuit 71 and the second drive circuit 72 substantially at the same time, it depends on the input timing. There is a possibility that the first drive circuit 71 and the second drive circuit 72 receive control signals of different BPP phases. For example, there is a possibility that the first drive circuit 71 receives the control signal of the first control circuit 61, and the second drive circuit 72 receives the control signal of the second control circuit 62. In this way, if the first drive circuit 71 and the second drive circuit 72 receive control signals of different BPP phases, normal BPP operation cannot be performed. For example, in the above example, the drive pulse is output to the four phases of the UX phase and the VY phase, and normal BPP operation cannot be performed.

On the other hand, in the first control device 31 according to the present embodiment, the first control circuit 61 and the second control circuit 62 select the conduction phase switch unit 51 from the timing of the output of the control signal to a predetermined period. It is a selection prohibition period that prohibits.

For example, in the example shown in FIG. 3, in the first control circuit 61, the BPP command is input after the end of the selection prohibition period. Therefore, the first control circuit 61 outputs a control signal for BPP operation immediately after receiving the input of the BPP command. On the other hand, in the second control circuit 62, the BPP command is input during the selection prohibition period. Therefore, after inputting the BPP command, the second control circuit 62 outputs a control signal for BPP operation according to the end of the selection prohibition period. In other words, the second control circuit 62 delays the output of the control signal for the BPP operation until the selection prohibition period ends.

As a result, it is possible to prevent the control signals of different BPP operations from the first control circuit 61 and the second control circuit 62 from being input to the first drive circuit 71 and the second drive circuit 72 substantially at the same time. In this example, the first-come-first-served circuit of the first drive circuit 71 and the second drive circuit 72 can receive only the control signal of the BPP operation from the first control circuit 61.

As described above, in the first control device 31 according to the present embodiment, the BPP operation can be performed more stably even when the control circuits 61 and 62 and the drive circuits 71 and 72 are made redundant.

In order to appropriately suppress that the control signals of different BPP operations from the first control circuit 61 and the second control circuit 62 are input to the first drive circuit 71 and the second drive circuit 72 substantially at the same time, the selection is made. It is necessary to make the length of the prohibition period longer than the length of the timing shift of the output of the control signal. The length of the timing deviation of the output of the control signal is, for example, about 5 ° in the phase angle. For example, when the system frequency of the first AC power system 2a is 50 Hz, it is about 270 μs. Therefore, the length of the selection prohibition period is preferably set to 300 μs or more. As a result, it is possible to appropriately prevent the control signals of different BPP operations from the first control circuit 61 and the second control circuit 62 from being input to the first drive circuit 71 and the second drive circuit 72 substantially at the same time. can. Further, if the length of the selection prohibition period is set to be excessively long, the BPP operation is delayed and the timing of inputting the next control signal in the normal operation is approached. Therefore, the length of the selection prohibition period is preferably set to 500 μs or less. That is, it is preferable to set the length of the selection prohibition period to about 300 μs or more and 500 μs or less. The length of the selection prohibition period is preferably shorter than the interval at which the control signal is input to each switch unit 51 in normal operation.

Further, in the first control circuit 61 and the second control circuit 62, one of the first control circuit 61 and the second control circuit 62 fails, and the other of the first control circuit 61 and the second control circuit 62 Under the condition of operating alone, the selection prohibition period is canceled. For example, when the number of control circuits is three or more, the selection prohibition period is canceled under the condition that the plurality of control circuits are operated independently by only one of the plurality of control circuits. As a result, it is possible to prevent the transition to the BPP operation from being delayed due to the selection prohibition period under the condition of independent operation.

(Second embodiment)
FIG. 4 is a block diagram schematically showing the first power conversion device according to the second embodiment.
As shown in FIG. 4, in the first power conversion device 11a of the power conversion system 10a, each of the switch portions 51 of the first separately excited power converter 21 has the separately excited switching element 51s and is a detection unit. Has 51a. In the present embodiment, those having substantially the same function and configuration as the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The detection unit 51a detects the conduction state of the switch unit 51, and inputs the continuity state signal indicating the continuity state of the switch unit 51 to the first control device 31a via the signal line 41. More specifically, the conduction state of the switch unit 51 is the state of the voltage applied to the switch unit 51 and the state of the current flowing through the switch unit 51. The detection unit 51a detects that the switch unit 51 is conducting, for example, when a voltage of a predetermined value or more is applied to the switch unit 51 or when a current of a predetermined value or more is flowing through the switch unit 51.

The first control device 31a inputs the continuity state signal input from the detection unit 51a of each switch unit 51 to the first drive circuit 71 and the second drive circuit 72, and also inputs the first drive circuit 71 and the second drive circuit 72. Is input to the first control circuit 61 and the second control circuit 62 via.

FIG. 5 is a timing chart schematically showing an example of the operation of the first control device according to the second embodiment.
As shown in FIG. 5, in this example, the first control circuit 61 and the second control circuit 62 select the switch portion 51 of the conduction phase based on the continuity state signal in response to the input of the BPP command. That is, when the BPP command is input, the first control circuit 61 and the second control circuit 62 select the switch unit 51 whose conduction state signal represents the continuity state as the switch unit 51 of the conduction phase.

At this time, as shown in FIG. 5, the first control circuit 61 and the second control circuit 62 are BPP for a predetermined period from the timing when the conduction state signal is switched from the non-conduction state to the continuation state in the normal operation. Even when a command is input, the selection prohibition period is set to prohibit the selection of the switch unit 51 of the conduction phase.

As shown in FIG. 5, the timing of switching the continuity state signal of the first control circuit 61 is determined by the deviation of the incoming timing of the continuity state signal between the first control circuit 61 and the second control circuit 62. 2 There is a possibility that the timing of switching the continuity state signal of the control circuit 62 will be different.

When the selection prohibition period is not set as described above and the BPP command is input in the period in which the switching timing of the conduction state signal is deviated as shown in FIG. 5, the first control circuit 61 and A different BPP phase is selected in the second control circuit 62. For example, in the example shown in FIG. 5, the first control circuit 61 selects the switch unit 51u (U phase) as the switch unit 51 of the conduction phase, whereas the second control circuit 62 selects the switch unit 51z (Z). Phase) is selected as the switch portion 51 of the conductive phase. Therefore, as in the above embodiment, there is a possibility that normal BPP operation cannot be performed.

On the other hand, in the first control device 31a according to the present embodiment, the first control circuit 61 and the second control circuit 62 have a predetermined period from the timing when the conduction state signal is switched from the non-conducting state to the conducting state. The selection prohibition period is set to prohibit the selection of the switch portion 51 of the conduction phase.

For example, in the example shown in FIG. 5, in the first control circuit 61, the BPP command is input after the end of the selection prohibition period. Therefore, the first control circuit 61 outputs a control signal for BPP operation immediately after receiving the input of the BPP command. On the other hand, in the second control circuit 62, the BPP command is input during the selection prohibition period. Therefore, after inputting the BPP command, the second control circuit 62 outputs a control signal for BPP operation according to the end of the selection prohibition period. In other words, the second control circuit 62 delays the output of the control signal for the BPP operation until the selection prohibition period ends.

As a result, similarly to the first embodiment, control signals of different BPP operations from the first control circuit 61 and the second control circuit 62 are input to the first drive circuit 71 and the second drive circuit 72 substantially at the same time. It is possible to prevent it from being lost. Even when the control circuits 61 and 62 and the drive circuits 71 and 72 are made redundant, the BPP operation can be performed more stably.

In order to appropriately suppress that the control signals of different BPP operations from the first control circuit 61 and the second control circuit 62 are input to the first drive circuit 71 and the second drive circuit 72 substantially at the same time, the selection is made. It is necessary to make the length of the prohibition period longer than the length of the timing shift of the switching of the continuity state signal. The length of the timing shift of the switching of the conduction state signal is about 100 μs at the longest. Therefore, the length of the selection prohibition period is preferably set to 100 μs or more. The length of the selection prohibition period is preferably set to, for example, about 100 μs or more and 500 μs or less.

Further, also in this example, in the first control circuit 61 and the second control circuit 62, a failure or the like occurs in either one of the first control circuit 61 and the second control circuit 62, and the first control circuit 61 and the second control circuit 62 Under the condition that only the other side of the control circuit 62 is operated independently, the selection prohibition period is canceled. For example, when the number of control circuits is three or more, the selection prohibition period is canceled under the condition that the plurality of control circuits are operated independently by only one of the plurality of control circuits. As a result, it is possible to prevent the transition to the BPP operation from being delayed due to the selection prohibition period under the condition of independent operation.

(Third embodiment)
FIG. 6 is a block diagram schematically showing the first control device according to the third embodiment.
As shown in FIG. 6, in the first control device 31b of this example, the first drive circuit 71 and the second drive circuit 72 have selection circuits 71a and 72a, respectively. Since the configurations other than the first control device 31b can be the same as the configurations of the first embodiment, detailed description thereof will be omitted.

In the first control device 31b, the first control circuit 61 and the second control circuit 62 select the continuity phase switch unit 51 based on the control signal or the continuity state signal finally output in response to the input of the BPP command. At the same time, the switch unit 51 of the BPP phase is selected, and the control signal of the BPP operation for firing the switch unit 51 is input to the first drive circuit 71 and the second drive circuit 72. In this example, the first control circuit 61 and the second control circuit 62 do not set the selection prohibition period when selecting the switch portion 51 of the conduction phase.

The selection circuits 71a and 72a provide a confirmation period for the control signal for the BPP operation when the control signal for the BPP operation is input from one of the first control circuit 61 and the second control circuit 62. The selection circuits 71a and 72a set a predetermined period as a confirmation period from the timing at which the control signal for BPP operation is input. The selection circuits 71a and 72a do not input the drive pulse to the switch unit 51 based on the control signal of the BPP operation during the confirmation period.

In the selection circuits 71a and 72a, after the control signal for BPP operation is input from one of the first control circuit 61 and the second control circuit 62, the selection circuits 71a and 72a are input from the other of the first control circuit 61 and the second control circuit 62 during the confirmation period. When the BPP operation control signal is not input, the drive pulse is input to the switch unit 51 based on the input BPP operation control signal.

On the other hand, in the selection circuits 71a and 72a, after the control signal for the BPP operation is input from one of the first control circuit 61 and the second control circuit 62, the selection circuits 71a and 72a of the first control circuit 61 and the second control circuit 62 during the confirmation period. When the control signal for BPP operation is input from the other side, the control signal for BPP operation in the delayed phase is selected. The lagging phase is a phase that conducts later in normal operation.

For example, when the control signal of the BPP operation of the UX phase and the control signal of the BPP operation of the VY phase are input, the selection circuits 71a and 72a select the control signal of the BPP operation of the VY phase. For example, when the control signal of the BPP operation of the VY phase and the control signal of the BPP operation of the WZ phase are input, the selection circuits 71a and 72a select the control signal of the BPP operation of the WZ phase. For example, when the control signal of the BPP operation of the WZ phase and the control signal of the BPP operation of the UX phase are input, the selection circuits 71a and 72a select the control signal of the BPP operation of the UX phase.

For example, as shown in FIG. 6, the control signal of the BPP operation of the UX phase is output from the first control circuit 61, the control signal of the BPP operation of the VY phase is output from the second control circuit 62, and the first drive circuit. It is assumed that the control signal from the first control circuit 61 arrives first in 71, and the control signal from the second control circuit 62 arrives first in the second drive circuit 72. In this case, in both the first drive circuit 71 and the second drive circuit 72, the control signal for the BPP operation of the VY phase, which is the delayed phase, is selected.

Therefore, it is possible to prevent the first drive circuit 71 and the second drive circuit 72 from selecting different BPP phases. As a result, even when the control circuits 61 and 62 and the drive circuits 71 and 72 are made redundant, the BPP operation can be performed more stably.

When the number of control circuits and drive circuits is three or more, the plurality of drive circuits receive the BPP operation control signal when the BPP operation control signal is input from any of the plurality of control circuits. A predetermined period is set as the confirmation period from the input timing, and if the BPP operation control signal is not input from any of the plurality of control circuits during the confirmation period, the input BPP operation control is performed. When a drive pulse is input to the switch unit 51 that performs BPP operation based on the signal and a control signal for BPP operation is input from another of a plurality of control circuits during the confirmation period, a plurality of input signals are input. The control signal of the delayed phase may be selected from the control signals, and the drive pulse may be input to the switch unit 51 that performs the BPP operation based on the control signal of the delayed phase.

In order to appropriately suppress the selection of different BPP phases in the first drive circuit 71 and the second drive circuit 72, the length of the confirmation period is set in the first control circuit 61 and the second control circuit 62. It is necessary to make it longer than the length of the input timing deviation of the control signal input from each. The length of the timing deviation of the input of the control signal is about 100 μs at the longest. Therefore, the length of the confirmation period is preferably set to 100 μs or more. The length of the confirmation period is preferably set to, for example, about 100 μs or more and 500 μs or less.

Note that control signals for BPP operations of different phases were input to the first drive circuit 71 and the second drive circuit 72 from the redundant first control circuit 61 and second control circuit 62 within the confirmation period. At this time, as a rule for selecting the BPP phase, a method of selecting a leading phase and a method of selecting a lagging phase can be considered.

Regarding the method of selecting the lead phase, the first drive circuit 71 and the second drive circuit 71 and the second drive circuit 71 are used when the control signal for BPP operation is input from the first control circuit 61 and the second control circuit 62 before and after the end of the confirmation period. The BPP phase selected with the drive circuit 72 may be different.

For example, the first control circuit 61 inputs a control signal for BPP operation in the VY phase to the first drive circuit 71 and the second drive circuit 72, and the second control circuit 62 is in the UX phase before and after the end of the confirmation period. It is assumed that a control signal for BPP operation is input.

The timing at which the first drive circuit 71 and the second drive circuit 72 receive the control signal for BPP operation is different due to individual differences in the operation delay of the optical input / output circuit, individual differences in the operation delay of the electronic components, and the like. The first drive circuit 71 receives the control signal of the BPP operation of the UX phase from the second control circuit 62 before the confirmation period ends, and the second drive circuit 72 receives the UX from the second control circuit 62 after the confirmation period ends. There is a possibility of receiving the control signal of the phase BPP operation.

At this time, when the method of selecting the lead phase is adopted, the second drive circuit 72 selects the VY phase, which is the only BPP operation control signal received within the confirmation period, but the first drive circuit 71 determines. The UX phase is selected in order to select the leading phase from the BPP operation control signals received within the confirmation period. As a result, the BPP phase selected between the first drive circuit 71 and the second drive circuit 72 is different. On the other hand, when the method of selecting the delayed phase is adopted, since the VY phase is selected for both the first drive circuit 71 and the second drive circuit 72, selection is made between the first drive circuit 71 and the second drive circuit 72. The BPP phases to be made match.

When the first control circuit 61 and the second control circuit 62 output the control signal of the BPP operation with a sufficient time difference of the confirmation period, the control circuit that outputs the control signal of the BPP operation later (delayed by the confirmation period) , The BPP phase of the same phase or the leading phase is selected for the control circuit that outputs the control signal of the BPP operation in advance. Therefore, in the first drive circuit 71 and the second drive circuit 72, the BPP phase selected between the first drive circuit 71 and the second drive circuit 72 does not match by adopting the method of selecting the delayed phase. Can be avoided.

Further, in the first drive circuit 71 and the second drive circuit 72, one of the first drive circuit 71 and the second drive circuit 72 fails, and the other of the first drive circuit 71 and the second drive circuit 72 Under the condition of operating alone, the confirmation period is canceled. For example, when the number of drive circuits is three or more, the confirmation period is canceled under the condition that the plurality of drive circuits are operated independently by only one of the plurality of drive circuits. As a result, it is possible to prevent the transition to the BPP operation from being delayed due to the confirmation period under the condition of independent operation.

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 variations 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.

2a 1st AC power system, 2b 2nd AC power system, 4 host device, 10, 10a power conversion system, 11, 11a 1st power conversion device, 12 2nd power conversion device, 14 DC circuit, 14n negative DC bus , 14p positive DC bus, 14x DC reactor, 14y DC reactor, 21 1st separately excited power converter, 22 2nd separately excited power converter, 31, 31a, 31b 1st controller, 32 2nd controller, 41 Signal line, 41a light guide, 42 signal line, 44 network, 51 switch section, 61 1st control circuit, 62 2nd control circuit, 71 1st drive circuit, 72 2nd drive circuit

Claims (6)

A control device that controls power conversion by a separately excited power converter having a plurality of bridge-connected switches.
A plurality of control circuits that generate control signals for controlling the continuity of the plurality of switch units, and
With a plurality of drive circuits that generate a drive pulse for conducting the plurality of switch units based on the control signal input from any of the plurality of control circuits and input the drive pulse to the plurality of switch units. ,
Equipped with
The operation can be continued by any one of the plurality of control circuits and any one of the plurality of drive circuits.
The plurality of control circuits are bypass pairs instructing execution of a bypass pair operation in which the high-voltage side switch unit and the low-voltage side switch unit connected to the same phase of the plurality of switch units are simultaneously in a conductive state. When a command is input, the switch section of the conduction phase is selected from the plurality of switch sections based on the control signal output last, and the bypass pair operation is performed based on the switch section of the conduction phase. In the normal operation of selecting the switch unit to perform the bypass pair operation, inputting the control signal to the switch unit performing the bypass pair operation to the plurality of drive circuits, and controlling the power conversion by the separately excited power converter. A control device having a predetermined period from the output timing of the control signal as a selection prohibition period for prohibiting selection of the switch portion of the conduction phase even when the bypass pair command is input. The control device according to claim 1, wherein the plurality of control circuits are operated independently by only one of the plurality of control circuits, and the selection prohibition period is canceled. A control device that controls power conversion by a separately excited power converter having a plurality of bridge-connected switches.
A plurality of control circuits that generate control signals for controlling the continuity of the plurality of switch units, and
With a plurality of drive circuits that generate a drive pulse for conducting the plurality of switch units based on the control signal input from any of the plurality of control circuits and input the drive pulse to the plurality of switch units. ,
Equipped with
The operation can be continued by any one of the plurality of control circuits and any one of the plurality of drive circuits.
The plurality of control circuits receive a continuity state signal indicating a continuity state of the plurality of switch units from the plurality of switch units.
The plurality of control circuits are bypass pairs instructing execution of a bypass pair operation in which the high-voltage side switch section and the low-voltage side switch section connected to the same phase of the plurality of switch sections are simultaneously in a conductive state. When a command is input, a switch unit of the conduction phase among the plurality of switch units is selected based on the conduction state signal, and a switch that performs the bypass pair operation based on the switch unit of the conduction phase. In the normal operation of selecting a unit, inputting the control signal to the switch unit performing the bypass pair operation to the plurality of drive circuits, and controlling the power conversion by the separately excited power converter, the continuity A control device in which a predetermined period from the timing at which the state signal is switched from the non-conducting state to the conducting state is a selection prohibition period in which selection of the switch portion of the conduction phase is prohibited even when the bypass pair command is input. The control device according to claim 3, wherein the plurality of control circuits cancel the selection prohibition period under the condition that only one of the plurality of control circuits is operated independently. A control device that controls power conversion by a separately excited power converter having a plurality of bridge-connected switches.
A plurality of control circuits that generate control signals for controlling the continuity of the plurality of switch units, and
With a plurality of drive circuits that generate a drive pulse for conducting the plurality of switch units based on the control signal input from any of the plurality of control circuits and input the drive pulse to the plurality of switch units. ,
Equipped with
The operation can be continued by any one of the plurality of control circuits and any one of the plurality of drive circuits.
The plurality of control circuits are bypass pairs instructing execution of a bypass pair operation in which the high-voltage side switch unit and the low-voltage side switch unit connected to the same phase of the plurality of switch units are simultaneously in a conductive state. When a command is input, the switch section of the conduction phase among the plurality of switch sections is selected, the switch section that performs the bypass pair operation is selected based on the switch section of the conduction phase, and the bypass pair is selected. The operation of inputting the control signal to the operation switch unit to the plurality of drive circuits is performed, and the operation is performed.
The plurality of drive circuits confirm a predetermined period from the timing at which the control signal of the bypass pair operation is input when the control signal of the bypass pair operation is input from any of the plurality of control circuits. If the control signal for the bypass pair operation is not input from any of the plurality of control circuits during the confirmation period, the control signal for the bypass pair operation is input. Based on this, when the drive pulse is input to the switch unit that performs the bypass pair operation and the control signal of the bypass pair operation is input from another of the plurality of control circuits during the confirmation period, the control signal is input. A control device that selects the control signal of the delayed phase from the plurality of input control signals and inputs the drive pulse to the switch unit that performs the bypass pair operation based on the control signal of the delayed phase. The control device according to claim 5, wherein the plurality of drive circuits cancel the confirmation period under the condition that only one of the plurality of drive circuits is operated independently.

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