JP3162546B2 - Control device of AC / DC converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an AC / DC converter used for a frequency converter, a DC power transmission facility, and the like.

[0002]

2. Description of the Related Art FIG. 5 is a schematic block diagram for explaining a control device of a conventional AC / DC converter using a DC / DC converter in DC power transmission equipment. The converters 1A and 1B are connected by a DC transmission line 3, and the DC side of each converter 1A and 1B is connected via a DC reactor 2A and 2B, respectively, and the AC side is connected to converter transformers 4A and 4B and circuit breakers 5A and 5B. Are connected to the respective AC systems 6A and 6B via the power supply.

Conventionally, converters 1A and 1B have constant margin angle control circuits 12A and 12B, constant voltage control circuits 11A and 11B,
Constant current control circuits 13A and 13B are provided, and the constant margin angle control circuits 12A and 12B
A, 18B output the converter 1A, 1
It operates so that the margin angle of B follows.

[0006] A voltage reference value which is an output of each of the DC voltage setting units 14A and 14B and a DC voltage are converted into DC voltage detectors 15A and 15A.
The difference between the DC voltage detection value input to the summing circuits 17A and 17B via the voltage / voltage conversion circuits 16A and 16B for detection at 5B and conversion to a value that can be easily handled by the control circuit is determined by the summing circuits 17A and 17B. The obtained value is input to the constant voltage control circuits 11A and 11B, so that the DC voltage of the DC transmission line 3 is controlled so as to follow the voltage reference value. Transmission control circuit 2
6A and 26B, and a DC current detection value, which is a DC current detected by DC current detectors 21A and 21B and converted to a value which can be easily handled as a control circuit by current / voltage conversion circuits 22A and 22B. Summing circuits 23A, 23
B is input. The value of the difference is the constant current control circuit 13A,
By being input to 13B, the DC current flowing through the DC transmission line 3 is controlled to follow the current reference.

The switches 24A and 24B are closed only for the converter that performs the reverse conversion operation of the converter, and the current margins output from the current margin setting units 25A and 25B are input to the summing circuits 23A and 23B. Is done. The function of the current margin and the output of the constant margin control circuits 12A and 12B, the constant voltage control circuits 11A and 11B, and the constant current control circuits 13A and 13B are the most suitable for the control angle of the converter. If the switch 24B is now closed and the switch 24A is not open due to the function of the control advance angle priority circuits 28A and 28B that make only the advanced output the output, the control advance angle priority circuit 28A The output of the constant current control circuit 13A is output, and the control advance angle priority circuit 28B outputs to the control margin angle control circuit 12B and the output of the constant voltage control circuit 11B the one that is advanced as the control angle. Generally, the output of the constant voltage control circuit 11B is output. Each of the control lead angle priority circuits 28A,
The output of 28B is input to phase control circuits 29A and 29B, where it is converted into a pulse signal that determines the ignition timing of the converter, and is provided as a gate pulse signal to each converter via pulse amplifier circuits 30A and 30B. It is configured to be.

The construction of the control circuit as described above and the control operation thereof are known techniques. Next, a general control method when the control device is configured as a double system will be described. FIG. 6 shows a schematic block diagram of a general dual system control system. Components having the same functions as those described in FIG. 5 are denoted by the same reference numerals. Since the converter control devices 100AA and 100AB are of a dual system, the function of each control device is provided with a code indicating a control device sequence.

When the control circuit is a dual system, control amounts are coordinated at a stage prior to output to the phase control circuit in order to prevent variations in the output of each control system. As the method, the output value of the control angle advance priority circuit 28AA of the own series and the output value of the control angle advance priority circuit 28AB of the other series are selected by the selection circuit 50AA.
In general, a control amount to be input to the phase control circuit 29A and output to the phase control circuit 29A is selected. The selection circuit 50AB performs the same operation. Further, when an abnormality occurs in one of the series of control devices, the phase control output of the series in which the abnormality has occurred is stopped and the series is separated, and the healthy series selection circuit 50 does not select the control amount of the series in which the abnormality has occurred. Operate.

[0008]

The prior art shown in FIG. 6 has the following disadvantages. When recovering from the disconnected state, the sequence in which an error has occurred is determined by the time it takes to determine that the sequence is normal and the time the control operation value transitions to the converter operating point at that time. There is a difference. In the case of a normal device, the time when the control calculation value is shifted to the operating point because the control signal is calculated so that the input signal to the device becomes a normal value and the control signal follows the normal value after the sequence is judged to be normal Is longer. For example, it is assumed that the output value of the control calculation is a value whose phase is considerably advanced from the actual operating point when the sequence is determined to be normal and the selection of inter-series cooperation is started. When the selection circuit is advanced selection, the phase is advanced instantaneously, the overcurrent occurs in the case of forward converter operation, the voltage becomes low in the case of reverse converter operation, and the DC system is disturbed. And may adversely affect systems and equipment. Such a phenomenon similarly occurs even when the selection circuit gives priority to the phase delay.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. When the control device of the AC / DC converter is constituted by a multiplex system and one system is restored from a disconnected state, the operation state is adversely affected. It is an object of the present invention to provide a control device of an AC / DC conversion device, which can perform control while giving inter-sequence coordination of control amounts without giving.

[0010]

In order to achieve the above object, the present invention provides a constant voltage control circuit, a constant margin angle control circuit, a constant current control circuit, and an output value of each of the control circuits. And a selection circuit for selecting a value to be output to the phase control circuit from an output value of the circuit and an output value of the control advance angle priority circuit of another system. In the control device of the AC / DC converter, detecting that one of the control circuits of the own series has failed, and applying the output of the control advance angle priority circuit of the own series to the selection circuit of the own series and the other series. And a means for comparing the output values of the control lead angle priority circuits of the own series and the other series and canceling the interruption on condition that the difference is within a certain constant value. is there.

According to another aspect of the present invention, there is provided a constant voltage control circuit, a constant margin angle control circuit, a constant current control circuit, and a control angle which is an output value of each of the control circuits. Of a control lead angle priority circuit that takes advance lead of the control circuit, and a selection circuit that selects a value output to the phase control circuit from an output value of the circuit and an output value of the control lead angle priority circuit of another series. In the control device, means for detecting that one of the control circuits of the own series has failed, and interrupting application of the output of the control lead angle priority circuit of the own series to the selection circuits of the own series and the other series. And a means for comparing the output values of the control lead angle priority circuits of the own series and the other series and releasing the cutoff on condition that the difference is within a certain constant value for a predetermined time period. Things.

Further, in order to achieve the above object, a third aspect is provided.
The invention of a constant voltage control circuit, a constant margin angle control circuit, a constant current control circuit, a control advance angle priority circuit for taking advance priority of the control angle which is the output value of each control circuit, In a control device of an AC / DC converter having a minimum value selection circuit for selecting a value to be output to a phase control circuit from an output value and an output value of a control advance angle priority circuit of another system, any one of the control circuits of the own system Means that the output of the control advance angle priority circuit of the own series is applied to the selection circuits of the own series and the other series, and the control advance angle priority of the own series and the other series. The output values of the circuits are compared, and the output value of the control advance angle priority circuit of the own series is larger than the output value of the control advance angle of the other series, and it is continued for a predetermined time that the difference is within a certain constant value. Means for releasing the cutoff on the condition that It is obtained by Bei.

Further, in order to achieve the above object, the invention according to claim 4 comprises a constant voltage control circuit, a constant margin angle control circuit,
A constant current control circuit, a control advance angle priority circuit that takes advance priority of a control angle that is an output value of each of the control circuits, a phase from an output value of the circuit and an output value of another series of control advance angle priority circuits. In the control device of the AC / DC conversion device having a maximum value selection circuit for selecting a value to be output to the control circuit, the control device detects that any of the control circuits in the own system has failed, and the control lead angle priority circuit in the own system. Means for interrupting the output of the control circuit from being applied to the selection circuits of the own series and the other series, and comparing the output values of the control advance angle priority circuits of the own series and the other series. A means for canceling the interruption is provided on condition that the output value is smaller than the output value of the control lead angle of the other series and that the difference is within a certain constant value for a predetermined time.

[0014]

According to the first aspect of the present invention, when operating in a multiplex system, the output value of the control lead angle priority circuit is transmitted and received between the sequences and the selection circuit cooperates between the sequences. When there is a disconnected series, the system is operated with the output value of the healthy series without selecting the output value of the separated series, and when restoring the separated series, the control output of the series restoration is restored. In order to prevent adverse effects on operating conditions due to disturbance,
After it is confirmed by the comparator that the difference between the output value of the separated sequence and the output value of the healthy sequence is within a certain fixed value, the selection circuit starts coordination between the sequences.

According to the second aspect of the present invention, by giving a certain time limit to the judgment of the comparator, when the control operation of the recovery sequence is in a transient state, the output values needlessly coincide with each other. It is no longer determined to be present, and disturbance of the control output when the inter-system cooperation is started is prevented.

Further, according to the third aspect of the present invention, when the selection circuit selects the minimum value, the comparator sets the output value of the control advance angle priority circuit of the restored series to the control advance angle of the healthy series. Judgment that the output value is larger than the output value and within a certain fixed value difference is performed to prevent disturbance of the control output when the inter-sequence cooperation is started.

Further, according to the fourth aspect of the present invention, when the selection circuit selects the maximum value, the comparator sets the output value of the control advance angle priority circuit of the restored series to the control advance angle of the healthy series. By judging that the output value is smaller than the output value and within a certain value difference, when performing series restoration, selection is started in a state where the output value of the series to be restored is not selected. The sequence can be restored without giving any disturbance to the output.

[0018]

FIG. 1 is a block diagram of an embodiment according to the present invention. In FIG. 1, elements performing the same functions as in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted. Control circuit 100AA
Is a constant voltage control circuit 11AA, a constant margin angle control circuit 12A
A, constant current control circuit 13AA, control lead angle priority circuit 28
AA, selection circuit 50AA, abnormality detection circuit 31AA, flip-flop circuits 32AA, 33AA, and circuit 34
AA, 35AA, comparator 36AA, switch 37AA,
38AA.

Since the functions of the control circuits 100AA and 100AB are the same, only the operation of 100AA will be described here. Output value of constant voltage control circuit 11AA, output value of constant margin angle control circuit 12AA, and constant current control circuit 13
The output value of AA is input to the control advance priority circuit 28AA,
The value of the control advance is selected.

In the abnormality detection circuit 31AA, the control device 100
The AA abnormality is monitored, and if an abnormality occurs, "1" is output upon abnormality detection. Its output is also output to other streams. The flip-flop circuit 32AA is connected to the abnormality detection circuit 31.
When the output of AA is "1", the output is set and the switch 37AA is operated.

Flip-flop circuits 32AA, 33AA
Switches 37AA and 38AA when there is no output from
Is off, the output value of the control advance angle priority circuit 28AA and the output value of the control advance angle priority circuit 28AB are input to the selection circuit 50AA, and an output for coordination between streams is selected.

When the output of abnormality detection circuit 31AA is "1", flip-flop circuit 32AA is set and 37A
A operates and the input to the selection circuit 50AA is the control lead angle priority circuit 28AB. Only the output value is input to the selection circuit 50AA. Since the two input values are the same in the selection circuit 50AA, the output value of the control lead angle priority circuit 28AB is selected as a result.

In the comparator 36AA, the control lead angle priority circuit 2
The output value of 8AA is compared with the output value of the control lead angle priority circuit 28AB, and if the difference is within a certain value, "1" is output. In the AND circuit 34AA, the output of the abnormality detection circuit 31AA is "0" and the output of the comparator is "1".
If so, "1" is output. Flip-flop circuit 3
2AA is reset by the output "1" from the AND circuit 34AA. Since the switch of 37AA is returned by the reset, the input to the selection circuit 50AA is again performed by the output value of the control advance angle priority circuit 28AA and the control advance angle priority circuit 28AA.
The output values of AB are two values.

The same operation is performed when the abnormality detection circuit 31AB of another system operates. in this way,
According to the above-described embodiment, when the control device of the AC / DC conversion device is configured by a multiplex system and one system is recovered from a disconnected state,
Since it is possible to control while coordinating the control amounts between the series without giving any disturbance to the operation state, if one series becomes abnormal, the fault is investigated during operation and the equipment is restored and the converter is restored. It is possible to restore the control system to the series in the operating state without stopping the operation of the system, and it is possible to prevent the system and devices from being adversely affected.

Next, the second aspect of the present invention will be described.
FIG. 3 is a block diagram showing a specific example of the comparator 36AA of FIG. 1 for explaining the second aspect of the present invention. Comparator 36
AA includes a comparison circuit 60AA and an on-delay 70AA.

The comparison circuit 60AA compares the output value of the control lead angle priority circuit 28AA with the output value of the control lead angle priority circuit 28AB, and outputs "1" if the difference is within a certain value. . The on-delay 70AA outputs "1" when the output from the comparison circuit 60AA continues for a certain time period.

With this configuration, when the output from the abnormality detection circuit 31AA becomes "0" and the series is restored, when the control operation of the restoration series is in a transient state, the outputs are unnecessarily matched. It is not necessary to make a determination, and it is possible to prevent disturbance of the control output when the selection of inter-series cooperation is started.

Next, the third aspect of the present invention will be described.
FIG. 2 is a block diagram of the third embodiment of the present invention, and FIG. 4 is a block diagram of the comparators 36AA and 36AA 'of FIG.
In FIG. 2, elements performing the same functions as in FIG. 1 and FIG. 4 are denoted by the same reference numerals.

The control circuit 100AA includes a constant voltage control circuit 11
AA, constant margin angle control circuit 12AA, constant current control circuit 13
AA, control lead angle priority circuit 28AA, selection circuit 50A
A, abnormality detection circuit 31AA, flip-flop circuit 32
AA, 33AA, AND circuits 34A, 35AA, comparators 36AA, 36AA ', and switches 37AA, 38AA.

The comparator 36AA comprises a comparator 61AA and an on-delay 70AA. Comparator 36AA '
Is composed of a comparison circuit 62AA and an on-delay 70AA.

The feature of this configuration is that it has two comparators. This is for changing the judgment of the comparator according to the selection state of the selection circuit 50AA. Here, the case where the selection circuit 50AA performs the minimum value selection (control advance priority) will be described. The comparator 36AA is used to make a decision when recovering from a state where the own series is abnormal and disconnected. Therefore, in the comparator 62AA, the control lead angle priority circuit 2 of the own system is used.
From the output value Ec A of 8AA and the output value Ec B of the control lead angle priority circuit 28AB of the other series, it is determined that a> Ec A−Ec B> = 0 (a: an arbitrary value). Sets the output to "1". The selection is started when the output value of the own series to be restored is a value not selected. The comparator 36AA 'is for making a judgment when recovering from a state in which the other series is abnormal and disconnected. Therefore, in the comparison circuit 61AA, the output value Ec A of the control lead angle priority circuit 28AA of the own system is used.
And the output value Ec of the control lead angle priority circuit 28AB of the other series.
From B, it is determined that a> Ec B−Ec A> = 0 (a: an arbitrary value). If the determination is made, the output is set to “1”. The selection is started when the output value of the other series to be restored is a value that is not selected.

When the selection state of the selection circuit 50AA is the maximum value selection, the functions of the comparators 61AA and 62AA are interchanged. As described above, when performing series restoration, selection is started in a state where the output value of the series to be restored is not selected, so that it is possible to perform series restoration without disturbing the output more smoothly. Become.

[0033]

As described above, according to the first aspect of the present invention, a control device for controlling an AC / DC converter for converting AC power to DC power or DC power to AC power is constituted by a multiplex system. In the control device of the device, when operating in a multiplex system, the output value of the control advance angle priority circuit is exchanged between the systems, and the selection circuit cooperates with the system. When the operation is performed with the output value of the healthy series without selecting the output value of the normal series, and the separated series is restored, a comparator is used to prevent adverse effects on the operation state due to disturbance of the control output at the time of series restoration. To provide a control device of an AC / DC conversion device that starts coordination between sequences by a selection circuit after a difference between an output value of a separated sequence and an output value of a healthy sequence is confirmed to be within a certain fixed value. Can be.

Further, according to the second aspect of the present invention, by giving a certain time limit to the judgment of the comparator, the output values needlessly coincide with each other when the control operation of the restoration sequence is in a transient state. Thus, it is possible to provide a control device of the AC / DC conversion device that prevents disturbance of the control output when the selection of the inter-series cooperation is started.

Further, according to the third aspect of the present invention, when the selection circuit selects the minimum value, the comparator sets the output value of the control advance angle priority circuit of the series to be restored to the output of the control advance angle of the healthy series. It is determined that the value is larger than the value and within a certain fixed value difference. Further, according to the invention of claim 4, when the selecting circuit selects the maximum value, the comparator determines whether the sequence to be recovered is When performing a series recovery by determining that the output value of the control advance angle priority circuit is smaller than the output value of the control advance angle of the healthy series and within a certain fixed value difference, the output value of the series to be restored Since the selection is started in a state where is not selected, it is possible to provide a control device of the AC / DC conversion device which can recover the sequence more smoothly without disturbing the output.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a control device of an AC / DC converter according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a control device of an AC / DC converter according to another embodiment of the present invention.

FIG. 3 is a block diagram showing another embodiment of the comparator of FIG. 1;

FIG. 4 is a block diagram showing a specific example of the comparator shown in FIG. 2;

FIG. 5 is a configuration diagram of a control device of a conventional AC / DC converter.

FIG. 6 is a block diagram of a conventional dual system control device for controlling the AC / DC converter.

[Explanation of symbols]

1A, 1B ... Converter 2A, 2B
… DC reactor 3… DC transmission line 4A, 4B
… Transformer transformers 5A, 5B… Breakers 6A, 6B
… AC system 11A, 11B… Constant voltage control circuit 12A, 12B
… Constant margin angle control circuits 13A, 13B… Constant current control circuits 14A, 14B
… DC voltage setting device 15A, 15B… DC voltage detector 16A, 16B
… Voltage / voltage conversion circuit 17A, 17B… Summing circuit 18A, 18B
… Margin angle setting device 19… Transmission circuits 21A and 21B
… DC current detectors 22A, 22B… Current / voltage conversion circuits 23A, 23B
… Summing circuit 24A, 24B… Switch 25A, 25B
… Current margin setting device 26A, 26B… Transmission control circuit 27
… Current reference value output circuit 28A, 28B… Control lead angle priority circuit 29A, 29B
… Phase control circuit 30A, 30B… Pulse amplifier circuit 31AA
… Abnormality detection circuit 32AA, 33AB… Flip-flop circuit 34AA, 35AA
… And circuit 36AA, 36AA '… Comparator 37AA, 38AA
... Switch 50AA, 50AB ... Selection circuit 100AA, 100AB
… Transducer controller

Claims (4)

(57) [Claims] 1. A constant-voltage control circuit, a constant-margin-angle control circuit, a constant-current control circuit, a control-advance-angle priority circuit for prioritizing a control angle that is an output value of each of the control circuits, and the circuit. In the control device of the AC / DC conversion device provided with a selection circuit for selecting a value to be output to the phase control circuit from the output value of the other system and the output value of the control advance angle priority circuit, any one of the control circuits of the own system Means for detecting that a failure has occurred and blocking the output of the control advance angle priority circuit of the own series from being applied to the selection circuit of the own series and the other series; and the control advance angle priority circuit of the own series and the other series A control device for an AC / DC converter, comprising: means for comparing the output values of the above-mentioned items and canceling the interruption on condition that the difference is within a certain constant value. 2. A constant voltage control circuit, a constant margin angle control circuit, a constant current control circuit, a control advance angle priority circuit that takes advance of a control angle that is an output value of each of the control circuits, and the circuit. In the control device of the AC / DC conversion device provided with a selection circuit for selecting a value to be output to the phase control circuit from the output value of the other system and the output value of the control advance angle priority circuit, any one of the control circuits of the own system Means for detecting that a failure has occurred and blocking the output of the control advance angle priority circuit of the own series from being applied to the selection circuit of the own series and the other series; and the control advance angle priority circuit of the own series and the other series A control device for an AC / DC conversion device, comprising means for comparing the output values of the above-mentioned items and canceling the interruption on condition that the difference is within a certain constant value for a predetermined time. 3. A constant-voltage control circuit, a constant-margin-angle control circuit, a constant-current control circuit, a control-advance-angle-priority circuit for prioritizing a control angle that is an output value of each of the control circuits, and the circuit. A minimum value selecting a value to be output to the phase control circuit from the output value of the other system and the output value of the control advance angle priority circuit. Means for detecting that any of the control circuits has failed, means for cutting off the output of the control advance angle priority circuit of the own series to be applied to the selection circuit of the own series and the other series, and The output value of the control advance angle priority circuit is compared, and the output value of the control advance angle priority circuit of the own series is larger than the output value of the control advance angle of the other series, and the difference is within a certain constant value. Release the cutoff on condition that has continued for a predetermined time Control device for AC-DC converter comprising comprises a stage. 4. A constant-voltage control circuit, a constant-margin-angle control circuit, a constant-current control circuit, a control-advance-angle priority circuit for prioritizing a control angle, which is an output value of each of the control circuits, A maximum value for selecting a value to be output to the phase control circuit from the output value of the other system and the output value of the control advance angle priority circuit. Means for detecting that any of the control circuits has failed, means for cutting off the output of the control advance angle priority circuit of the own series to be applied to the selection circuit of the own series and the other series, and The output value of the control advance angle priority circuit is compared, and the output value of the control advance angle priority circuit of the own series is smaller than the output value of the control advance angle of the other series, and the difference is within a certain constant value. Release the cutoff on condition that has continued for a predetermined time Control device for AC-DC converter comprising comprises a stage.