JP2020065348A - Controller, power system, control method, and program - Google Patents

Abstract

To provide a controller, a power system, a control method, and a program capable of smoothly performing transition to single operation.SOLUTION: A controller is for controlling a self-excited power converter connected to an AC system and a DC system. When no first signal is input for making a first circuit breaker an open state for connecting the AC system and a load capable of supplying power from both of the AC system and the self-excited power converter, a control unit of the controller outputs a gate signal based on a first voltage command value based on a voltage detection value of the AC system and a current detection value of the AC system to the self-excited power converter. During a first set time after the first signal is input, the control unit outputs no gate signal to the self-excited power converter. After the first set time has elapsed after the first signal was input, the control unit outputs the gate signal based on a second voltage command value derived so as to bring a voltage detection value of the AC system closer to a voltage command value of the AC system to the self-excited power converter.SELECTED DRAWING: Figure 2

Description

  Embodiments of the present invention relate to a control device, a power system, a control method, and a program.

  Conventionally, a self-excited power converter operates so as to output the specified active power or reactive power during normal times, and if the AC power source is lost due to a system accident, the self-excited power converter outputs the AC power. It serves as a supply source, maintains the amplitude and phase of the AC voltage, and is controlled so as to supply the active and reactive powers required by the electric device to the electric device. However, when a predetermined event such as an accident occurs in the system, the transition to the isolated operation may not be performed smoothly depending on the time until the completion of the accident removal.

JP, 2003-134669, A

  The problem to be solved by the present invention is to provide a control device, a power system, a control method, and a program that can smoothly perform a transition to an isolated operation.

The control device of the embodiment is a control device that controls a self-excited power converter connected to an AC system and a DC system. The control device has a control unit. The control unit, when the first signal for opening the first circuit breaker that connects the AC system and the load capable of supplying power from both the AC system and the self-excited power converter is not input, A gate signal based on a first voltage command value based on a voltage detection value of the AC system and a current detection value of the AC system is output to the self-excited power converter. The control unit does not output the gate signal to the self-excited power converter for a first set time after the first signal is input, and the first set time has elapsed since the first signal was input. Thereafter, a gate signal based on a second voltage command value derived so as to bring the detected voltage value of the AC system closer to the voltage command value of the AC system is output to the self-excited power converter.
Control device.

The figure which shows an example of the usage environment of the control apparatus 30 contained in the electric power system 1 which concerns on 1st Embodiment. The figure which shows an example of a functional structure of the control apparatus 30. The timing chart which shows the timing of the process etc. which are performed in the electric power system 1. The figure which shows an example of a timing chart which shows the timing of a process etc. when a pulse generation part does not wait for the output of a gate signal. The figure showing an example of functional composition of electric power system 1A of a 2nd embodiment. The timing chart which shows the timing of the process etc. which are performed in 1 A of electric power systems. The figure which shows an example of a functional structure of the electric power system 1B of the modification 1 of 1st Embodiment and 2nd Embodiment. The figure showing an example of functional composition of electric power system 1C of modification 2 of a 1st embodiment and a 2nd embodiment. The figure which shows an example of a function structure of the electric power system 1D of the modification 2 of 1st Embodiment and 2nd Embodiment. It is a figure showing an example of functional composition of control device 30A of the modification 4.

  Hereinafter, a control device, an electric power system, a control method, and a program of an embodiment are explained with reference to drawings.

(First embodiment)
FIG. 1 is a diagram illustrating an example of a usage environment of a control device 30 included in the power system 1 according to the first embodiment. The power system 1 includes, for example, an AC voltage source 10, an AC power transmission line 12, a first breaker 14, a second breaker 16, an AC bus 18, a load 20, a power converter 22, and a current detector. It includes a device 24, a voltage detector 26, and a controller 30. The power system 1 also includes, for example, an AC voltage source 100, an AC bus 102, a power converter 106, a current detector 108, a voltage detector 110, and a controller 112.

  The second cutoff unit 16 and the power converter 22 are connected via an AC bus (AC system) PL1, and the power converter 22 and the power converter 106 are connected via a DC bus (DC system) PL2. The second cutoff unit 16 is electrically connected to the first cutoff unit 14 via an AC system. Each of the power converter 22 and the power converter 106 is, for example, a self-excited power converter that mutually converts AC and DC.

  First, the islanding operation will be described. When a system fault occurs on the AC voltage source 10 (backside system) side of the first cutoff unit 14 and the first cutoff unit 14 is opened, the system on the power converter 22 side of the first cutoff unit 14 is set behind Separated from the system side and becomes a single system. Although a power supply source such as a generator does not exist in the single grid, the control device 30 operates the power converter 22 as an AC power supply source to supply power to the load 20 connected to the single grid. Is continued. This operation of the power converter 22 is called an independent operation.

  When the self-excited power converter performs normal operation that outputs the specified active power and reactive power to the grid at normal time, and when it operates alone as an AC power supply source for the single grid, The power converter 22 has different control modes. In the control mode of the power converter 22 during the islanding operation, the self-exciting power converter performs control to keep the voltage of the AC bus PL1 constant, so that the load 20 in the island system generates the necessary active power and reactive power. This is a mode for supplying to the load 20 (CVCF control mode).

  The AC voltage source 10 and the first cutoff unit 14 are electrically connected via the AC power transmission line 12. When the first cutoff unit 14 is in the ON state (closed state), the AC voltage source 10 and the AC bus 18 are electrically connected. When the first blocking unit 14 is in the off state (open state), the AC voltage source 10 and the AC bus 18 are electrically separated.

  The second cutoff unit 16 and the load 20 are electrically connected to each other through the AC bus 18. When the second cutoff unit 16 is in the on state (closed state), the load 20 and the power converter 22 are electrically connected. When the second cutoff unit 16 is in the off state (open state), the load 20 and the power converter 22 are electrically separated.

  The AC bus 18 is electrically connected to the DC terminal side of the power converter 22 via the AC bus PL1, and the DC converter side of the power converter 22 is electrically connected to the DC terminal side via the DC bus PL2. Connected.

  The current detector 24 is, for example, between the AC bus 18 and the power converter 22, and is electrically connected to the AC bus PL1. The current detector 24 may be provided on a member (for example, an arm) that constitutes the power converter 22.

  The voltage detector 26 is electrically connected to the AC bus 18, for example. The voltage detector 26 detects the voltage of the AC bus 18.

  The load 20 is, for example, a device or load used by a consumer or the like. The load 20 receives power from one or both of the AC system (the AC voltage source 10 and the AC bus 18) and the power converter 22.

  The control device 30 acquires the detection result of the current detector 24 and the detection result of the voltage detection unit 26, and performs various controls based on the acquired information and the like. The functional configuration and control contents of the control device 30 will be described later.

  The power converter 22 is electrically connected to the DC terminal side of the power converter 106, and the AC bus bar 102 is electrically connected to the AC terminal side of the power converter 106. Power converter 106 is electrically connected to AC voltage source 100 via AC bus PL3 (AC system).

  The current detection unit 108 is, for example, between the AC bus 102 and the power converter 106, and is electrically connected to the AC bus PL3. The voltage detection unit 110 is electrically connected to the AC bus bar 102, for example. The voltage detection unit 110 detects the voltage of the AC bus 102.

  The control device 112 acquires the detection result of the current detector 108 and the detection result of the voltage detection unit 110, and converts the AC power into the DC power or the DC power into the AC power based on the acquired information and the like. To do

  FIG. 2 is a diagram illustrating an example of a functional configuration of the control device 30. The control device 30 includes, for example, a phase derivation unit 32, a dq conversion unit 34, a dq conversion unit 36, an AC current control unit 38, an AC voltage control unit 40, a dq inverse conversion unit 42, and a pulse generation unit 44. And an adjusting unit 46. These components are realized, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Further, some or all of these constituent elements are hardware (circuits) such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), and GPU (Graphics Processing Unit). Part; including circuitry), or may be realized by cooperation of software and hardware. Note that some or all of these components or some or all of the components included in these components may be circuits. The AC current control unit 38, the AC voltage control unit 40, the dq inverse conversion unit 42, the pulse generation unit 44, and the adjustment unit 46 are examples of a “control unit”. The alternating current control unit 38 is an example of a “first derivation unit”. The AC voltage control unit 40 is an example of a “second derivation unit”.

  The phase deriving unit 32 derives the phase θ1 of the AC system used during normal operation. The phase derivation unit 32 derives the phase of the voltage for each of the three phases of the AC bus 60 based on the voltage detection value V detected by the voltage detector 26, and the derived phase θ1 is sent to the dq inverse conversion unit 42. Output.

  The phase deriving unit 32 derives the phase θ2 according to the output power used during the islanding operation when an opening signal described later is input. The phase deriving unit 32 determines, for example, the output frequency f (for example, 50 [Hz] in eastern Japan and 60 [Hz] in western Japan) when the power converter 22 operates independently and operates as a voltage source. Set. The phase derivation unit 32 derives the phase of the voltage to be output by the power converter 22 based on the set frequency, and outputs the derived phase θ2 to the dq inverse conversion unit 42.

  The dq conversion unit 34 uses the phase information derived by the phase derivation unit 32 to convert the three-phase current detection value, which is the detection result of the current detector 24, into the two-phase current detection value, which is the conversion result. The active component current Id and the reactive component current Iq are output to the alternating current control unit 38.

  The dq conversion unit 36 uses the phase information derived by the phase derivation unit 32 to convert the three-phase voltage detection value, which is the detection result of the voltage detector 26, into a two-phase voltage detection value, which is the conversion result. The active component voltage command value Vsd and the reactive component voltage command value Vsq are output to the AC current control unit 38.

  The alternating current control unit 38 derives an effective component voltage command value Vcd1 and a reactive component voltage command value Vcq1 used during normal operation. The alternating current control unit 38, based on the active component current Id output by the dq conversion unit 34, the active component voltage Vsd output by the dq conversion unit 36, and the active power command value Pref, the active component voltage command value. Derive Vcd1. For example, the AC current control unit 38 derives the active component voltage command value Vcd1 so that the power converter 22 outputs active power that matches the active power command value Pref.

  Based on the reactive current Iq output by the dq conversion unit 34, the reactive voltage Vsq output by the dq conversion unit 36, and the reactive power command value Qref, the AC current control unit 38 receives the reactive voltage command. The value Vcq1 is derived. For example, the AC current control unit 38 derives the reactive voltage command value Vcq1 so that the power converter 22 outputs reactive power that matches the reactive power command value Qref. The alternating current control unit 38 outputs the derived effective component voltage command value Vcd1 and reactive component voltage command value Vcq1 to the dq inverse conversion unit 42.

  The AC voltage control unit 40 derives an effective component voltage command value Vcd2 and a reactive component voltage command value Vcq2 that are used during isolated operation. The AC voltage control unit 40, based on the effective component current Id output by the dq conversion unit 34, the effective component voltage Vsd output by the dq conversion unit 36, and the AC voltage command value Vsdref, the effective component voltage command value. Derive Vcd2. For example, the AC voltage control unit 40 derives the effective voltage command value Vcd2 so that the power converter 22 outputs a voltage that matches the AC voltage command value Vcdref.

  The AC voltage control unit 40, based on the reactive current Iq output by the dq conversion unit 34, the reactive voltage Vsq output by the dq conversion unit 36, and the AC voltage command value Vsqref, the reactive voltage command value. Derive Vcq2. For example, the AC voltage control unit 40 derives the reactive voltage command value Vcq2 so that the power converter 22 outputs an AC voltage that matches the AC voltage command value Vcqref. For example, when the open signal is input, the AC voltage control unit 40 derives the effective component voltage command value Vcd2 and the reactive component voltage command value Vcq2, and outputs the derivation result to the dq inverse conversion unit 42. When the open signal is not input, the effective component voltage command value Vcd1 and the reactive component voltage command value Vcq1 are output to the dq inverse conversion unit 42.

  The open signal S (first signal) is, for example, a signal output when the first cutoff unit 14 is controlled to be in an open state when a system abnormality or the like occurs and the power converter 22 is a single system. . The open signal S is a signal output when the power supply from the other device to the AC system is reduced.

  The dq inverse conversion unit 42 performs dq inverse conversion based on the voltage command value and the phase, converts the two-phase voltage command value into a three-phase voltage command value, and generates the converted three-phase voltage command value as a pulse. It is output to the unit 44. When the open signal S is not input, the dq inverse conversion unit 42 performs the dq inverse conversion based on the phase θ1, the effective component voltage command value Vcd1, and the reactive component voltage command value Vcq1. When the open signal S is input, the dq inverse conversion unit 42 performs the dq inverse conversion based on the phase θ2, the effective voltage command value Vcd2, and the reactive voltage command value Vcq2.

  The pulse generator 44 generates a gate signal to be given to the switching element of the power converter 22 based on the voltage command value output from the dq inverse converter 42, and outputs the generated gate signal to the power converter 22. The power converter 22 executes control suitable for normal operation or single operation based on the gate signal output by the pulse generator 44.

  When the release signal S is input, the adjustment unit 46 outputs an instruction to stop the output (or generation) of the gate signal to the pulse generation unit 44 during the first set time. During the first set time, the preset first circuit breaker 14 starts to operate, and the system of the first circuit breaker 14 on the side of the AC transmission line 12 and the system of the first circuit breaker 14 on the side of the AC bus line 18 are operated. Is a time set on the basis of the time estimated to be required to electrically separate the. The first set time is a time preset based on experiments, simulations, and the like. As a result, the pulse generator 44 stops the output (or generation) of the gate signal during the set time.

  FIG. 3 is a timing chart showing timings of processing and the like performed in the power system 1. It is assumed that at time t, a predetermined event (for example, a system fault such as a ground fault or a leakage) has occurred in the system on the side of the AC power transmission line 12 with respect to the first circuit breaker 14. In this case, at time t + 1, the first cutoff unit 14 outputs the opening signal S and performs the opening operation for putting the own device in the open state. At time t + 2, when the opening signal S is input to the adjustment unit 46 of the control device 30, the adjustment unit 46 stops the operation of causing the pulse generation unit 44 to output the gate signal during the first set time T (( Or wait). Time t + 3 is the time when the opening operation of the first cutoff unit 14 is completed and the predetermined event is resolved. The elimination of the predetermined event means that the location where the predetermined event occurs and the AC bus 18 are separated by the operation of the first circuit breaker 14.

  Time t + 4 is the time when the first set time T has elapsed from the time when the opening signal was input to the adjustment unit 46. At time t + 4, the pulse generation unit 44 outputs to the power converter 22 a gate signal generated based on the effective voltage command value Vcd2 and the reactive voltage command value Vcq2.

  Thereby, the power converter 22 executes control according to the gate signal generated based on the effective component voltage command value Vcd2 and the reactive component voltage command value Vcq2. As a result, it is possible to smoothly shift to the isolated operation.

  For example, when the pulse generation unit does not wait for the output of the gate signal for the first set time, the power converter executes the control based on the output gate signal before the opening operation of the first cutoff unit is completed. I have something to do. FIG. 4 is a diagram showing an example of a timing chart showing the timing of processing and the like when the pulse generator does not wait for the output of the gate signal. In this case, the islanding operation may be started before the system accident or the like is removed, and when the power converter supplies power to the system, overcurrent or overvoltage may occur.

  On the other hand, the control device 30 of the present embodiment stops outputting the gate signal during the first set time T in order to suppress the overcurrent and the overvoltage, as described in FIG. 3 above. To do. As a result, it is possible to smoothly shift to the isolated operation.

  For the purpose of strengthening interconnection and promoting the introduction of renewable energy, DC transmission systems and frequency conversion systems are being introduced. Self-excited power converters using self-extinguishing type semiconductor devices such as IGBTs (Insulated Gate Bipolar Transistors), which are applied to these systems, serve as AC voltage sources and supply power to electrical equipment. be able to. Taking advantage of this feature, the self-excited power converter operates to output the specified active power or reactive power during normal operation, and if the AC power source is lost due to a system accident, the self-excited power converter operates It acts as a power supply source, maintains the amplitude and phase of the AC voltage, and performs the operation to supply the necessary active power and reactive power required by the electric equipment. For example, in the system to be compared, the self-exciting power converter switches from the normal operation to the operation that serves as the AC power supply source by receiving the open signal of the breaker in the AC system.

  However, which of the time until completion of the main line interruption (removal of the accident) and the time until the self-excited power converter receives the open signal depends on the timing of the accident occurrence or the like. In the system to be compared, the self-excited power converter may stop due to an overvoltage in the AC system or an overcurrent flowing in the self-excited power converter depending on the time until the completion of the accident elimination. For example, if the self-excited power converter receives a signal earlier than the fault elimination, a fault current flows to the fault point of the AC system, and the self-excited power converter stops due to overcurrent. If the self-exciting power converter shifts to constant voltage operation at the same time that the accident is cleared, and the self-exciting power converter was operating by inverter operation before shifting to constant voltage operation, the transient overvoltage increases and The protection stop of the power converter is reached.

  On the other hand, in the control device 30 of the present embodiment, when the AC power source is lost due to a system fault, the self-exciting power converter itself supplies AC power to the AC system near the self-exciting power converter. When the operation is switched to the power source, by temporarily stopping the ignition of the semiconductor elements that compose the self-excited power converter for a predetermined time, the self-excited power converter is irrespective of the time until the completion of the accident elimination. Can continue to operate.

  Specifically, in the control device 30 of the present embodiment, the power converter 22 temporarily blocks the gate for a predetermined time (the output of the gate signal is stopped) after receiving the open signal of the first circuit breaker 14, so that the power is not supplied. It prevents overcurrent from flowing through the converter 22. When the power converter 22 operates in the inverter operation before shifting to the independent operation and the power converter 22 shifts to the independent operation at the same time as the accident elimination, the second cutoff is performed to protect the converter itself from the increase of transient overvoltage. Although the device 16 trips (automatically shuts off), according to the present embodiment, the control device 30 stops the energy injection to the AC bus bar 18 by performing the gate blocking control. That is, control device 30 avoids an overvoltage by outputting a gate signal so that the voltage of AC bus 18 does not exceed the set value after the first set time has elapsed when the open signal is input. The trip of the second circuit breaker 16 can be avoided, and the continuity of operation of the power converter 22 can be improved.

  According to the first embodiment described above, when the adjustment unit 46 of the control device 30 receives the open signal S for controlling the first circuit breaker 14 provided on the AC system side to the open state, the open signal is released. By stopping the output of the gate signal based on the second voltage command value during the first set time T based on S, the transition to the islanding operation can be smoothly performed.

(Second embodiment)
The second embodiment will be described below. In the second embodiment, the control device 30 makes the standby time longer when the release signal is output a plurality of times than when the release signal is output once. Hereinafter, differences from the first embodiment will be mainly described.

  FIG. 5: is a figure which shows an example of a function structure of 1 A of electric power systems of 2nd Embodiment. The power system 1A includes a detection unit 13 and a monitoring device 130 in addition to the functional configuration of the power system 1. The detection unit 13 detects a predetermined event in the AC system. The monitoring device 130 monitors the occurrence of a predetermined event based on the detection result of the detection unit 13. The monitoring device 130 outputs the opening signal S1 to the first blocking unit 14 and the control device 30 when a predetermined event occurs.

  Further, the monitoring device 130 outputs the opening signal S2 to the first breaking unit 14 and the control device 30 when the operation of the first breaking unit 14 is not completed after outputting the opening signal S1. The open signal S2 is, for example, a signal output when the AC bus 18 and the AC power transmission line 12 are not separated within a predetermined time in the operation according to the open signal S1. For example, the monitoring device 130 acquires the operating state of the first cutoff unit 14 or the detection result of the cutoff detection unit included in the first cutoff unit 14 from the first cutoff unit 14, and based on the obtained result, the first cutoff unit. It is determined whether the operation of the unit 14 is completed. The interruption detecting unit, for example, completes the operation of the first interruption unit 14 based on the detection result of the current on the side of the AC bus 18 and the detection result of the current on the side of the AC power transmission line 12, and the AC bus 18 and It is detected whether or not the AC power transmission line 12 is separated.

FIG. 6 is a timing chart showing the timing of processing and the like performed in the power system 1A. It is assumed that a predetermined event has occurred at time t1. In this case, at time t 1 +1, the monitoring device 130 outputs the opening signal S1 to the first blocking unit 14 and the control device 30, for example, based on the detection result of the detection unit 13. When the opening signal S1 is input, the first cutoff unit 14 performs an opening operation that puts the device itself into an open state. At time t1 + 2, when the adjustment unit 46 of the control device 30 receives the opening signal S1, the adjustment unit 46 stops the operation of causing the pulse generation unit 44 to output the gate signal for the first set time T. Let

  At time t1 + 3, when the predetermined event has not been resolved, the monitoring device 130 outputs the opening signal S2 to the first shutoff unit 14 and the control device 30. When the opening signal S2 is input, the first cutoff unit 14 performs the opening operation to put the device in the open state again. The open signal S2 may be output before the first set time T elapses.

  At time t1 + 4, when the opening signal S2 is input, the control device 30 waits for a second set time T1 (<first setting time T or ≦ first setting time T) from the input of the opening signal S2. Extend. Then, the control device 30 causes the power converter 22 to start the isolated operation after the extended second set time T1 has elapsed. Note that the control device 30 outputs the gate signal from the time t1 + 2 to the second set time T1 (> the first set time T) instead of extending the standby for the second set time T1. You may stop. For example, the control device 30 may start measuring the second set time T1 from the time when the first set time T has elapsed, or may be longer than the first set time T from the time when the opening signal S1 is input. 2 The measurement of the set time T1 may be started.

  At time t1 + 5, when the operation of the first circuit breaker 14 is completed and the predetermined event is resolved, the control device 30 starts the output of the gate signal and starts the islanding operation of the power converter 22. Let

  As described above, even when the first circuit breaker 14 normally operates by one opening signal and the AC transmission line 12 and the AC bus 18 are not separated, the control device 30 outputs the second opening signal. When input, by extending the standby time for stopping the output of the gate signal, the transition to the islanding operation can be smoothly performed.

  In the above example, the case where the open signals S1 and S2 are input has been described. However, when the open signal S3 is input after the open signal S2 is input, the gate signal is output similarly to the above process. The time to wait to do may be extended.

  According to the second embodiment described above, the control device 30 inputs the second signal different from the first signal for controlling the first circuit breaker 14 to the open state after the first signal is input. In this case, after the first set time has elapsed, by stopping the output of the gate signal based on the second voltage command value and shifting to the islanding operation after a predetermined time, while suppressing overcurrent or overvoltage in the AC system, It is possible to smoothly shift to the independent operation.

(Modification 1)
Hereinafter, a modified example 1 of the first embodiment and the second embodiment will be described. The first modification of the first embodiment and the second embodiment is different from the power converter 106 and the control device 112 of the first embodiment and the second embodiment in that a direct current such as a secondary battery or a fuel cell is used. Equipped with a voltage source. FIG. 7: is a figure which shows an example of a functional structure of the electric power system 1B of the modification 1 of 1st Embodiment and 2nd Embodiment.

(Modification 2)
Hereinafter, a modified example 2 of the first embodiment and the second embodiment will be described. The second modification of the first embodiment and the second embodiment includes a phase adjusting facility 122 that adjusts reactive power, in addition to the functional configurations of the first embodiment and the second embodiment. FIG. 8: is a figure which shows an example of a functional structure of the electric power system 1C of the modification 2 of 1st Embodiment and 2nd Embodiment. In addition, in the power system 1C of the second modification, a separately excited power converter may be provided in addition to the power converter 22.

  If the power converter 22 starts the independent operation before the opening operation of the first cutoff unit 14 is completed, the residual current of the phase adjusting facility 122 that occurs during a system fault flows into the power converter 22 at the same time as the fault is removed, and the power is reduced. The converter 22 may stop. On the other hand, according to the power system 1B of the present embodiment, the power converter 22 is temporarily gate-blocked, so that the residual current of the phase-modulating equipment 122 is attenuated and the islanding operation is performed. Is prevented, and the continuity of operation of the power converter 22 is improved.

(Modification 3)
Modification 3 will be described below. The modification 3 has a functional configuration in which the modification 1 and the modification 2 are combined. A power system 1D of Modification 3 includes, for example, a DC voltage source 120 instead of the power converter 106 and the control device 112 of the first and second embodiments, and further includes a phase adjusting facility 122. FIG. 9: is a figure which shows an example of a function structure of the electric power system 1D of the modification 2 of 1st Embodiment and 2nd Embodiment.

(Modification 4)
Modification 4 will be described below. Modification 4 is different in the configuration of the control device from the configurations of the control devices of the first and second embodiments. In the first embodiment and the second embodiment, when the open signal is input to the AC voltage control unit 40, the effective component voltage command value Vcd2 and the reactive component voltage command value Vcq2 are output to the dq inverse conversion unit 42. It has been described that the active voltage command value Vcd1 and the reactive voltage command value Vcq1 are output to the dq inverse conversion unit 42 when the open signal is not input. In Modification 4, the selection adjustment unit 47 described later controls the voltage command value output to the dq inverse conversion unit 42.

  FIG. 10 is a diagram illustrating an example of a functional configuration of the control device 30A according to the fourth modification. The selection adjusting unit 47 outputs θ1 or θ2 output by the phase deriving unit 32, the effective component voltage command value Vcd1 and the reactive component voltage command value Vcq1 output by the AC current control unit 38, and the AC voltage control unit 40 outputs. The effective component voltage command value Vcd2, the reactive component voltage command value Vcq2, and the open signal are acquired.

  When the opening signal is input, the selection adjustment unit 47 converts the phase θ2, the effective component voltage command value Vcd2, and the reactive component voltage command value Vcq2 into the dq inverse conversion unit for the isolated operation after the first predetermined time T has elapsed. To 42. As a result, a gate signal for islanding operation is output to the power converter 22 after the first predetermined time T has elapsed. When the open signal is not input, the selection adjustment unit 47 outputs the phase θ1, the effective voltage command value Vcd1 and the reactive voltage command value Vcq1 to the dq inverse conversion unit 42 for normal operation.

  Further, instead of the above example, for example, the AC current control unit 38 or the AC voltage control unit 40 may execute the process of deriving the voltage command value based on the instruction of the selection adjustment unit 47. In this case, for example, the selection adjustment unit 47 causes the AC current control unit 38 to derive the voltage command value when the open signal is not input, and the AC command control unit 40 when the open signal is input. May be derived.

  Further, in the present embodiment, when the signal for opening the first circuit breaker 14 is input, the timing at which the power converter 22 performs the isolated operation is after the first circuit breaker 14 is opened. Of course, in order to realize this, it does not matter which functional unit among the functional units included in the above control device functions. For example, the generation or output of the gate signal may be configured to wait for the first predetermined time period in response to the input of the open signal, or the processing of the dq inverse conversion unit 42 may be configured to wait. May be.

  According to at least one embodiment described above, a control device for controlling a self-excited power converter connected to an AC system and a DC system, wherein the AC system, the AC system, and the self-excited power converter are provided. When the first signal for opening the first circuit breaker that connects the load capable of supplying power from both of the power supplies is not input, the voltage detection value of the AC system and the current detection value of the AC system are detected. Output a gate signal based on the first voltage command value based on the self-excited power converter, and do not output the gate signal to the self-excited power converter for a first set time after the first signal is input. , A gate signal based on a second voltage command value derived so as to bring the voltage detection value of the AC system closer to the voltage command value of the AC system after a first set time has elapsed since the first signal was input. The self-excited By having a control unit for outputting to a force transducer, it is possible to make the transition to a single operating smoothly.

  Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the invention described in the claims and the equivalents thereof as well as included in the scope and the gist of the invention.

DESCRIPTION OF SYMBOLS 10 ... AC voltage source, 12 ... AC transmission line, 14 ... 1st interruption | blocking part, 16 ... 2nd interruption | blocking part, 18 ... AC busbar, 22 ... Power converter, 24 ... Current detector, 26 ... Voltage detector, 30 .. control unit, 32 ... phase deriving unit, 34 ... dq conversion unit, 36 ... dq conversion unit, 38 ... AC current control unit, 40 ... AC voltage control unit, 42 ... dq inverse conversion unit, 44 ... pulse generation unit, 46 Adjustment unit

Claims (10)

A control device for controlling a self-excited power converter connected to an AC system and a DC system,
When the first signal for opening the first circuit breaker that connects the AC system and the load capable of supplying power from both the AC system and the self-excited power converter is not input, the AC system Outputting a gate signal based on a first voltage command value based on a voltage detection value and a current detection value of the AC system to the self-exciting power converter,
A gate signal is not output to the self-excited power converter during a first set time after the first signal is input,
A gate signal based on a second voltage command value derived so as to bring the voltage detection value of the AC system closer to the voltage command value of the AC system after a first set time has elapsed since the first signal was input. A control unit for outputting to the self-excited power converter,
Control device. The control unit is
A first derivation unit that derives a first voltage command value based on the detected voltage value of the AC system and the detected current value of the AC system;
A second derivation unit that derives a second voltage command value that is derived so that the detected voltage value of the alternating current system approaches the voltage command value of the alternating current system;
A generator that generates a gate signal to be output to the self-excited power converter based on the second voltage command value;
The gate signal is not output to the self-excited power converter during a first set time after the first signal is input, and the first set time has elapsed after the first signal was input, An adjusting unit configured to output a gate signal to the self-excited power converter,
The control device according to claim 1. During the first set time, the preset first circuit breaker starts operating, and the first side system of the first circuit breaker and the second side system of the first circuit breaker are electrically activated. It is the time set based on the estimated time required to physically separate,
The control device according to claim 1. When the second signal for opening the first circuit breaker, which is different from the first signal, is input after the first signal is input, the control unit performs the operation after the first set time elapses. Stopping the output of the gate signal based on the second voltage command value during the second set time,
The control device according to claim 1. When the second signal is input, the control unit starts measuring the second set time from the time when the first set time has elapsed, or when the second signal is input, The measurement of the third time including the first set time and the second set time is started from the time when one signal is input,
The control device according to claim 4. The control device according to any one of claims 1 to 5,
A self-exciting power converter having a first side connected to a first circuit breaker in which an AC bus and a load are connected in parallel, and a second side connected to a DC system;
Power system comprising. The first circuit breaker;
A second circuit breaker connected to the first circuit breaker via an AC system,
The electric power system according to claim 6. The second circuit breaker separates the electrical connection between the first circuit breaker and the self-excited power converter when a voltage equal to or higher than a set value is applied to the AC system,
When the first signal is input, the control device outputs the gate signal so that the voltage of the AC system does not exceed the set value after the first set time has elapsed,
The electric power system according to claim 7. A control method for controlling a self-excited power converter connected to an alternating current system and a direct current system,
When the first signal for opening the first circuit breaker that connects the AC system and the load capable of supplying power from both the AC system and the self-excited power converter is not input, the AC system Outputting a gate signal based on a first voltage command value based on a voltage detection value and a current detection value of the AC system to the self-exciting power converter,
A gate signal is not output to the self-excited power converter during a first set time after the first signal is input,
A gate signal based on a second voltage command value derived so as to bring the voltage detection value of the AC system closer to the voltage command value of the AC system after a first set time has elapsed from the input of the first signal. Output to the self-excited power converter,
Control method for self-excited power converter. In the computer of the control device for controlling the self-excited power converter connected to the AC system and the DC system,
When the first signal for opening the first circuit breaker that connects the AC system and the load capable of supplying power from both the AC system and the self-excited power converter is not input, the AC system Causing the self-excited power converter to output a gate signal based on a first voltage command value based on a voltage detection value and a current detection value of the AC system;
The gate signal is not output to the self-excited power converter during a first set time after the first signal is input,
A gate signal based on a second voltage command value derived so as to bring the voltage detection value of the AC system closer to the voltage command value of the AC system after a first set time has elapsed since the first signal was input. Output to the self-excited power converter,
program.

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