Excitation control device and excitation control method

Abstract

To appropriately diagnose an abnormality in an automatic voltage regulator in an excitation control device.SOLUTION: In an excitation control device having excitation controllers in two systems: a main system and a sub system, and controlling a synchronous machine, the excitation controllers in two systems respectively comprise: reactive power setting units (23A, 23B); reactive power adjustment devices (24A, 24B); voltage setting units (27A, 27B) that output voltage based on input increase or decrease instructions; and automatic voltage regulators (22A, 22B) that adjust voltage to be output based on the voltage output from the voltage setting units (27A, 27B). The excitation controllers are configured to have input circuits (25A, 25B, 26A, 26B, 28A, 28B, 29A, 29B) that input signals for causing the voltage setting unit (27A or 27B) in the sub system and the voltage setting unit (27B or 27A) in the main system to output the same signals during control of the reactive power.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an excitation control device for controlling the terminal voltage of a synchronous machine. [Background technology]

[0002] For example, excitation control devices that control the terminal voltage of a synchronous machine such as a synchronous generator are known, which have two excitation control units, one for a normal system and one for a standby system. One such excitation control device is the excitation control device 100 shown in Fig. 1. In the excitation control device 100, in both of the two excitation control units 11A and 11B, voltage setters (90R) 21A and 21B are adjusted by increase / decrease commands from automatic reactive power regulators (AQR) 24A and 24B in addition to increase / decrease commands from tracking control.

[0003] As a technology relating to an excitation control device for such a two-system synchronous machine, there is known an excitation control device and control method for a synchronous machine that always operates the excitation limiting control device for the normal system before the excitation limiting control device for the standby system, thereby eliminating erroneous diagnosis due to the occurrence of output deviation (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-107795 Summary of the Invention [Problem to be solved by the invention]

[0005] In the excitation control device 100 described above, an error in the synchronous machine reactive power Q detected by the P·Q converter can cause deviations in the voltage setters (90R) 21A, 21B, resulting in large deviations in the output signals of the automatic voltage regulators (AVRs) 22A, 22B of systems A and B. In this excitation control device, the excitation control units of both systems A and B are always in operation, and in the above-mentioned state, the deviations in the voltage setters (90R) 21A, 21B increase, affecting the voltage control system and creating an undesirable state for the operation of the synchronous generator 1. In this case, even though there is no abnormality in the automatic voltage regulators (AVRs) 22A, 22B themselves, the large deviation in the output signals can lead to a diagnosis of an abnormality.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique that enables appropriate diagnosis of abnormalities in an automatic voltage regulator in an excitation control device. [Means for solving the problem]

[0007] In order to achieve the above object, an excitation control device according to one aspect is an excitation control device that has two excitation control units, a main system and a secondary system, and controls a synchronous machine, wherein the excitation control units of the two systems each include a reactive power setting device that outputs a set value of reactive power, a reactive power adjustment device that receives as input a difference between the reactive power of the synchronous machine and the set value and outputs a power increase / decrease command so that the reactive power of the synchronous machine becomes the set value, and a voltage setting device that outputs a voltage based on the input increase / decrease command. and an automatic voltage regulator that adjusts the output voltage based on the voltage output from the voltage setter, and the excitation control device has an input circuit that inputs a signal to cause the voltage setter of the slave system and the voltage setter of the master system to output the same signal when controlling reactive power. [Effects of the Invention]

[0008] According to the present invention, it is possible to appropriately diagnose an abnormality in an automatic voltage regulator in an excitation control device. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the overall configuration of a conventional synchronous machine terminal voltage control system. [Figure 2] FIG. 2 is a diagram showing a part of the configuration of the excitation control device according to the first embodiment, including a synchronous machine signal detection and control circuit. [Figure 3] FIG. 3 is a diagram showing a part of the configuration of an excitation control device according to the second embodiment, including a synchronous machine signal detection and control circuit. [Figure 4] FIG. 4 is a diagram showing a part of the configuration of an excitation control device according to the third embodiment, including a synchronous machine signal detection and control circuit. DETAILED DESCRIPTION OF THE INVENTION

[0010] Some embodiments will be described with reference to the drawings. Note that the embodiments described below do not limit the invention according to the claims, and not all of the elements and combinations thereof described in the embodiments are necessarily essential to the solution of the invention.

[0011] FIG. 1 is a diagram showing the overall configuration of a conventional synchronous machine terminal voltage control system.

[0012] The synchronous machine terminal voltage control system 1000 includes a dual-system excitation control device 100 that uses thyristors. The synchronous machine terminal voltage control system 1000 includes a synchronous generator (GEN) 1 as an example of a synchronous machine, an excitation voltage transformer (EX-TR) 2, instrument voltage transformers (PT) 3A, 3B, instrument current transformers (CT) 4A, 4B, a field breaker (FS) 5, the excitation control device 100, a thyristor rectifier (THY) 10, and a synchronous machine field winding 13.

[0013] The excitation control device 100 includes excitation control sections 11A and 11B for two systems, system A and system B. Here, one of system A and system B operates as a main system (normal system), and the other operates as a secondary system (standby system).

[0014] The excitation control section 11A (11B) includes a synchronous machine signal detection and control circuit 6A (6B), a gate pulse generator (GPG) 8A (8B), and a change-over switch 9A (9B).

[0015] The synchronous machine signal detection and control circuit 6A (6B) includes a P / Q converter 14A (14B), a subtractor 16A (16B), 17A (17B), a voltage setting device (90R) 21A (21B), an automatic voltage regulator (AVR) 22A (22B), a reactive power setting device (a+bP) 23A (23B), and an automatic reactive power regulator (AQR) 24A (24B).

[0016] In the synchronous machine signal detection and control circuit 6A of the excitation control section 11A of system A (system A will be described as the main system here), a subtractor 17A subtracts the synchronous machine terminal voltage Vg detected by the instrument voltage transformer 3A from the voltage setting value output from the voltage setting device (90R) 21A to obtain a deviation signal value, and an automatic voltage regulator 22A supplies an output signal corresponding to the deviation signal value to a gate pulse generator (GPG) 8A, and the pulses output from the gate pulse generator 8A are input to a thyristor rectifier 10 via a change-over switch 9A. Based on the input pulses, the thyristor rectifier 10 controls the thyristor firing angle and produces an output, which is supplied to the synchronous machine field winding 13 via a field circuit breaker 5. This controls the terminal voltage of the synchronous generator 1 to be constant.

[0017] Furthermore, in the synchronous machine signal detection and control circuit 6A, the synchronous machine terminal voltage Vg detected by the instrument voltage transformer 3A and the synchronous machine load current Ig are input to a P·Q converter 14A, which inputs the synchronous machine reactive power Q to a subtractor 16A. The subtractor 16A subtracts the synchronous machine reactive power Q from the reactive power set value output from a reactive power setter (a+bP) 23A to obtain a deviation signal, and inputs this deviation signal to an automatic reactive power regulator 24A. The automatic reactive power regulator 24A outputs an adjustment command (increase / decrease command) based on the deviation signal and inputs it to a voltage setter 21A. The voltage setter 21A adjusts and outputs the voltage set value based on the adjustment command. In the excitation control device 100, similar processing is performed in parallel in the excitation control unit 11B of system B (secondary system), making it possible to instantly switch between system A and system B as the primary system, and allowing the operation of the synchronous generator 1 to continue without affecting the system in the event of a failure in one of the systems of the excitation control device 100.

[0018] Next, the excitation control device 110 according to the first embodiment will be described.

[0019] 2 is a diagram showing a part of the configuration of the excitation control device according to the first embodiment, including a synchronous machine signal detection and control circuit. Note that the same components as those of the excitation control device 100 shown in FIG. 1 are denoted by the same reference numerals.

[0020] The excitation control device 110 is configured such that, in the excitation control device 100, synchronous signal detection and control circuits 30A and 30B are provided instead of the synchronous machine signal detection and control circuits 6A and 6B, and further includes wiring 29A and 29B.

[0021] The synchronization signal detection and control circuit 30A (30B) includes a P / Q converter 14A (14B), a reactive power setting device 23A (23B), a subtractor 16A (16B), an automatic reactive power regulator (AQR) 24A (24B), a selection circuit 25A (25B), a selection circuit 26A (26B), a voltage setting device (90R) 27A (27B), an automatic tracking circuit (PTN) 28A (28B), a subtractor 17A (17B), and an automatic voltage regulator (AVR) 22A (22B).

[0022] Wiring 29A is connected so that the output of voltage setter 27A is input to automatic tracking circuits 28A and 28B. Wiring 29B is connected so that the output of voltage setter 27B is input to automatic tracking circuits 28A and 28B.

[0023] Here, the input circuit and command selection circuit are made up of selection circuits 25A and 25B, selection circuits 26A and 26B, automatic follow-up circuits 28A and 28B, and wiring 29A and 29B.

[0024] The automatic reactive power regulator 24A (24B) outputs an adjustment command (increase / decrease command) for the voltage output by the voltage setter 27A (27B) based on the input deviation signal ΔQ. In this embodiment, the automatic reactive power regulator 24A (24B) is wired so that an adjustment command to increase the voltage and an adjustment command to decrease the voltage are input to corresponding input terminals (increase terminal, decrease terminal) of the voltage setter 27A (27B) via separate wiring.

[0025] The voltage setter 27A (27B) sets the output voltage according to the input command. In this embodiment, the voltage setter 27A (27B) increases or decreases the voltage according to the input from the input terminals (increase terminal, decrease terminal).

[0026] The selection circuit 26A (26B) is disposed between the automatic reactive power regulator 24A (24B) and the voltage setter 27A (27B) and controls the opening and closing between them. When the A system (in the case of 26B, the B system) is the primary system, the selection circuit 26A (26B) is in a closed state, i.e., the selection circuit 26A (26B) inputs an adjustment command from the automatic reactive power regulator 24A (24B) to the voltage setter 27A (27B).

[0027] The automatic tracking circuit 28A (28B) is an example of a deviation calculation circuit, and outputs a voltage adjustment command to the voltage setter 27A (27B) so that the output voltage of the voltage setter 27A (27B) (the voltage from the wiring 29A (wiring 29B)) follows the output voltage of the voltage setter 27B (27A) of another system (the voltage from the wiring 29B (wiring 29A)). In this embodiment, the automatic tracking circuit 28A (28B) is wired so that an adjustment command to increase the voltage and an adjustment command to decrease the voltage are input to corresponding input terminals (increase terminal, decrease terminal) of the voltage setter 27A (27B) by separate wiring.

[0028] The selection circuit 25A (25B) is disposed between the automatic tracking circuit 28A (28B) and the voltage setter 27A (27B) and controls the opening and closing between them. When the A system (or the B system in the case of 25B) is the slave system, the selection circuit 25A (25B) is in the closed state, i.e., an adjustment command is input from the automatic tracking circuit 28A (28B) to the voltage setter 27A (27B). With this configuration, the voltage setting values ​​output from the voltage setters 27A and 27B are affected by the synchronous machine reactive power Q output from one of the P-Q converters 14A, 14B.

[0029] Next, a description will be given of the operation of the excitation control device 110. In this description, it is assumed that system A is controlled as the primary system and system B is controlled as the secondary system.

[0030] Automatic tracking circuits 28A, 28B determine the output deviation between voltage setters 27A and 27B, and if there is an output deviation, output an adjustment command (for example, an up / down pulse) according to the deviation so that the output deviation becomes zero. Here, since system B is the slave system, selection circuit 25B closes the connection between automatic tracking circuit 28B and voltage setter 27B, so that the output of automatic tracking circuit 28B is input to voltage setter 27B, and voltage setter 27B outputs a voltage setting value that follows the voltage setting value of voltage setter 27A.

[0031] Furthermore, since system A is the primary system, the selection circuit 26A closes the connection between the automatic reactive power regulator 24A and the voltage setter 27A, and when the excitation control device 110 is controlled to perform reactive power control, an adjustment command from the automatic reactive power regulator 24A is input to the voltage setter 27A via the selection circuit 26A, and the voltage set value is adjusted.

[0032] By this operation, the voltage setter 27B of the slave system outputs a voltage set value that follows the voltage setter 27A of the master system in accordance with an adjustment command from the automatic tracking circuit 28B, and the voltage set values ​​of the voltage setters 27A and 27B can be made to match in the slave system without being affected by detection errors of reactive power between the P / Q converters 14A and 14B. This makes it possible to prevent erroneous diagnosis in which an abnormality is detected due to an increase in the deviation of the output signals of the automatic voltage regulators 22A and 22B caused by the influence of detection errors of reactive power between the P / Q converters 14A and 14B.

[0033] Next, an excitation control device 120 according to a second embodiment will be described.

[0034] Fig. 3 is a diagram showing a part of the configuration of the excitation control device according to the second embodiment, including a synchronous machine signal detection and control circuit. Note that the same components as those in the excitation control devices shown in Figs. 1 and 2 are denoted by the same reference numerals.

[0035] The excitation control device 120 is configured such that, in place of the synchronous machine signal detection and control circuits 30A and 30B in the excitation control device 110, synchronization signal detection and control circuits 40A and 40B are provided, and further includes wiring 32A and 32B. The synchronization signal detection and control circuits 40A and 40B further include selection circuits 31A and 31B in the synchronous machine signal detection and control circuits 30A and 30B.

[0036] The wiring 32A (32B) is connected so that the deviation signal ΔQ, which is the output of the subtractor 16B (16A), is input to the selection circuit 31A (31B).

[0037] Here, the common input circuit is composed of selection circuits 31A and 31B and wirings 32A and 32B.

[0038] The selection circuit 31A (31B) is arranged between the subtractor 16A (16B) and the wiring 32A (32B) on the one hand and the automatic reactive power regulator 24A (24B) on the other hand, and controls opening and closing between them. When the A system (the B system in the case of 31B) is the primary system, the selection circuit 31A (31B) connects the subtractor 16A (16B) and the automatic reactive power regulator 24A (24B) on the other hand and disconnects the wiring 32A (32B) and the automatic reactive power regulator 24A (24B) on the other hand, when the A system (the B system in the case of 31B) is the secondary system, the selection circuit 31A (31B) disconnects the subtractor 16A (16B) and the automatic reactive power regulator 24A (24B) on the other hand and connects the wiring 32A (32B) and the automatic reactive power regulator 24A (24B) on the other hand.

[0039] Next, a description will be given of the operation of the excitation control device 120. In this description, it is assumed that system A is controlled as the primary system and system B is controlled as the secondary system.

[0040] Since system A is the primary system, the selection circuit 31A inputs the deviation signal ΔQ output by the subtractor 16A to the automatic reactive power regulator 24A, and the selection circuit 31B inputs the signal on the wiring 32B, i.e., the deviation signal ΔQ output by the subtractor 16A, to the automatic reactive power regulator 24B.

[0041] As a result, when the excitation control device 110 is controlled to perform reactive power control, in system A, an adjustment command is output from the automatic reactive power regulator 24A based on the deviation signal ΔQ output by the subtractor 16A, and the adjustment command is input to the voltage setter 27A via the selection circuit 26A, thereby adjusting the voltage set value.

[0042] On the other hand, since system B is the slave system, selection circuit 25B closes the connection between automatic tracking circuit 28B and voltage setter 27B, so that the output of automatic tracking circuit 28B is input to voltage setter 27B, and voltage setter 27B outputs a voltage set value that follows the voltage set value of voltage setter 27A.

[0043] By this operation, the voltage setter 27B of the slave system outputs a voltage set value that follows the voltage setter 27A of the master system in accordance with an adjustment command from the automatic tracking circuit 28B, and the voltage set values ​​of the voltage setters 27A and 27B can be made to match in the slave system without being affected by detection errors of reactive power between the P / Q converters 14A and 14B. This makes it possible to prevent erroneous diagnosis in which an abnormality is detected due to an increase in the deviation of the output signals of the automatic voltage regulators 22A and 22B caused by the influence of detection errors of reactive power between the P / Q converters 14A and 14B.

[0044] In this embodiment, the selection circuits 25A and 25B, the selection circuits 26A and 26B, the automatic tracking circuits 28A and 28B, and the wirings 29A and 29B may not be provided. In this case, in the secondary system B, the automatic reactive power regulator 24B outputs an adjustment command based on the signal on the wiring 32B, i.e., the deviation signal ΔQ output by the subtractor 16A, and this adjustment command is input to the voltage setter 27B to adjust the voltage set value. Therefore, the voltage set values ​​of the voltage setters 27A and 27B are adjusted based on the deviation signal ΔQ output by the subtractor 16A, and the voltage set values ​​of the voltage setters 27A and 27B can be made to match each other.

[0045] Next, an excitation control device 130 according to a third embodiment will be described.

[0046] Fig. 4 is a partial configuration diagram including a synchronous machine signal detection and control circuit of an excitation control device according to a third embodiment. Note that the same components as those in the excitation control devices shown in Figs. 1 and 3 are denoted by the same reference numerals.

[0047] The excitation control device 130 is provided with synchronization signal detection and control circuits 50A, 50B instead of the synchronous machine signal detection and control circuits 40A, 40B in the excitation control device 120, and is further provided with wiring 34A, 34B. The synchronization signal detection and control circuits 50A, 50B do not include the selection circuits 25A, 25B and automatic tracking circuits 28A, 28B in the synchronous machine signal detection and control circuits 40A, 40B, but instead include voltage setters 33A, 33B instead of the voltage setters 27A, 27B, and are further provided with selection circuits 35A, 35B.

[0048] In addition to the functions of the voltage setter 27A (27B), the voltage setter 33A (33B) further has a tracking function of outputting a voltage that tracks an input voltage. In this embodiment, the voltage setter 33A (33B) has a tracking input terminal and outputs the voltage input to the tracking input terminal as is.

[0049] The wiring 34A (34B) is connected so that the voltage output from the voltage setter 33A (33B) is input to the follow-up input terminal of the voltage setter 33B (33A) of the other system.

[0050] The selection circuit 35A (35B) is disposed between the wiring 34A (34B) and the voltage setter 33A (33B) and controls the opening and closing of the wiring 34A (34B). When the A system (or the B system in the case of 35B) is the secondary system, the selection circuit 35A (35B) connects the wiring 34A (34B) and the voltage setter 33A (33B), and when the A system (or the B system in the case of 35B) is the primary system, the selection circuit 35A (35B) disconnects the wiring 34A (34B) and the voltage setter 33A (33B).

[0051] Here, the tracking input circuit is composed of wirings 34A and 34B and selection circuits 35A and 35B.

[0052] Next, a description will be given of the operation of the excitation control device 130. In this description, it is assumed that system A is controlled as the primary system and system B is controlled as the secondary system.

[0053] When the excitation control device 130 is controlled to perform reactive power control, in system A, an adjustment command is output from the automatic reactive power regulator 24A based on the deviation signal ΔQ output by the subtractor 16A, and the adjustment command is input to the voltage setter 27A via the selection circuit 26A, and the voltage set value is adjusted.

[0054] On the other hand, since system B is the secondary system, selection circuit 35B closes the connection between wiring 34A and voltage setter 33B, so that the signal on wiring 34A, i.e., the output of voltage setter 33A, is input to voltage setter 33B, and voltage setter 33B outputs a voltage set value that follows (for example, is the same as) the output of voltage setter 33A.

[0055] By such an operation, the voltage setter of the slave system outputs a voltage set value that follows the voltage setter of the master system, and the voltage set values ​​of the voltage setters 33A and 33B can be made to match without being affected by the influence of reactive power detection errors between the P / Q converters 14A and 14B or the output deviation of the automatic reactive power regulators 24A and 24B. This makes it possible to prevent erroneous diagnosis in which an abnormality is detected due to an increase in the deviation of the output signals of the automatic voltage regulators 22A and 22B caused by the influence of reactive power detection errors between the P / Q converters 14A and 14B.

[0056] In this embodiment, the selection circuits 31A and 31B and the wirings 32A and 32B may not be provided. [Explanation of symbols]

[0057] 100, 110, 120, 130... Excitation control device, 6A, 6B, 30A, 30B, 40A, 40B, 50A, 50B... Synchronous machine signal detection and control circuit, 11A, 11B... Excitation control section, 21A, 21B, 27A, 27B, 33A, 33B... Voltage setting device, 22A, 22B... Automatic voltage regulator, 23A, 23B... Reactive power setting device, 24A, 24B... Automatic reactive power regulator, 25A, 25B... Selection circuit, 26A, 26B... Selection circuit, 28A, 28B... Automatic tracking circuit, 29A, 29B... Wiring, 31A, 31B... Selection circuit, 32A, 32B... Wiring, 34A, 34B... Wiring, 35A, 35B... Selection circuit, 1000... Synchronous machine terminal voltage control system

Claims

1. An excitation control device having two excitation control units, a main system and a secondary system, for controlling a synchronous machine, The two systems of excitation control units each include: a reactive power setting device that outputs a set value of reactive power; a reactive power adjusting device that receives a difference between the reactive power of the synchronous machine and the set value and outputs a command to increase or decrease power so that the reactive power of the synchronous machine becomes the set value; a voltage setting device that outputs a voltage based on an input increase / decrease command; an automatic voltage regulator that adjusts the output voltage based on the voltage output from the voltage setting device; The excitation control device has an input circuit for inputting a signal for causing a voltage setting device of a secondary system and a voltage setting device of a primary system to output the same signal when controlling reactive power. Excitation control device.

2. The input circuit a command selection circuit that inputs the increase / decrease command output from the reactive power adjustment device of the excitation control unit of the primary system to the voltage setting device of the primary system, and inputs a command to the voltage setting device of the secondary system to make the output of the voltage setting device of the secondary system follow the output of the voltage setting device of the primary system The excitation control device according to claim 1 .

3. The command selection circuit a selection circuit that inputs the output of the reactive power regulator of the excitation control unit of the main system to the voltage setting device; a deviation calculation circuit that calculates a deviation between the output of the voltage setting device of the primary system and the output of the voltage setting device of the secondary system; a selection circuit that inputs the output of the deviation calculation circuit of the excitation control unit of the slave system to the voltage setter of the slave system. The excitation control device according to claim 2 .

4. The input circuit a common input circuit that inputs the difference between the reactive power of the synchronous machine and the set value of the reactive power setting device of the main system to the reactive power adjustment devices of the main system and the secondary system; The excitation control device according to claim 1 .

5. The common input circuit A selection circuit is provided to which the difference between the reactive power of the synchronous machine and the set value of one reactive power setting device and the difference between the reactive power of the synchronous machine and the set value of the other reactive power setting device are input, and which selects the difference between the reactive power of the synchronous machine and the set value of the reactive power setting device of the main system and inputs it to the reactive power adjustment devices of the main system and the secondary system. The excitation control device according to claim 4.

6. the voltage setting device further has a tracking function for tracking an input voltage; The input circuit a follow-up input circuit for inputting a voltage output from the voltage setter of the primary system to the voltage setter of the secondary system so that the voltage output from the voltage setter of the secondary system follows the voltage output from the voltage setter of the primary system; The excitation control device according to claim 1 .

7. The tracking input circuit a selection circuit that selects the voltage output by the voltage setting device of the master system so as to be input to the follow-up function of the voltage setting device of the slave system; The excitation control device according to claim 6.

8. The input circuit a common input circuit that inputs the difference between the reactive power of the synchronous machine and the set value of the reactive power setting device of the main system to the reactive power adjustment devices of the main system and the secondary system; The excitation control device according to claim 2 .

9. the voltage setting device further has a function of following an input voltage; The input circuit a follow-up input circuit for inputting a voltage output from the voltage setter of the primary system to the voltage setter of the secondary system so that the voltage output from the voltage setter of the secondary system follows the voltage output from the voltage setter of the primary system; The excitation control device according to claim 4.

10. An excitation control method in an excitation control device that has two excitation control units, a main system and a secondary system, and controls a synchronous machine, comprising: The two systems of excitation control units each include: a reactive power setting device that outputs a set value of reactive power; a reactive power adjusting device that receives a difference between the reactive power of the synchronous machine and the set value and outputs a command to increase or decrease power so that the reactive power of the synchronous machine becomes the set value; a voltage setting device that outputs a voltage based on an input increase / decrease command; an automatic voltage regulator that adjusts the output voltage based on the voltage output from the voltage setting device; When controlling reactive power, a signal is input to the voltage setting device of the secondary system and the voltage setting device of the primary system to output the same signal. Excitation control method.

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