Protection relay device, protection and control system, and circuit breaker control method

Abstract

An abnormality in a reference voltage is appropriately detected while correcting fluctuations that occur due to fluctuations in the reference voltage in the detected value of power supplied to a power facility. [Solution] A protective relay device (24) includes a reference voltage generation unit (30) that generates a reference voltage Vref, a detection processing unit (50) that generates a detection value of the voltage or current supplied from a power system (10) to a power facility (12) using the reference voltage Vref, a correction value setting unit that sets a correction value, a correction processing unit that corrects the detection value in accordance with the correction value, and a circuit breaker control device (25) that controls a circuit breaker (22) that switches between supplying and cutting off power from the power system (10) to the power facility (12) in accordance with the detection value processed by the correction processing unit. When the reference voltage Vref is a value within a correction range that includes a target value, the correction value setting unit sets the correction value to a value corresponding to the difference between the reference voltage Vref and the target value, and when the reference voltage Vref is a value outside the correction range, the correction value setting unit sets the correction value to a value indicating no correction of the detection value.

Description

[Technical Field]

[0001] The present disclosure relates to a technique for controlling the supply / cutoff of power from a power grid to power equipment. [Background technology]

[0002] Various techniques for analyzing power transmitted to and received from a power grid have been proposed. For example, Patent Document 1 discloses a configuration in which detected values ​​of voltage and current in a power distribution line are corrected using a correction coefficient corresponding to the ratio between the detected value of a reference voltage and the factory value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-187426 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the configuration of Patent Document 1, the detected value of voltage or current is constantly corrected regardless of the ratio between the detected value of the reference voltage and the factory default value. Patent Document 1 also discloses that the detected value of voltage or current may be corrected only when the detected value of the reference voltage changes by more than a set value. Therefore, the technology of Patent Document 1 has a problem in that it cannot detect abnormal fluctuations in the reference voltage. In consideration of the above circumstances, one aspect of the present disclosure aims to appropriately detect abnormalities in the reference voltage while correcting fluctuations that occur due to fluctuations in the reference voltage in the detected value of power supplied to power equipment. [Means for solving the problem]

[0005] In order to solve the above problems, a protective relay device according to one embodiment of the present disclosure includes a reference voltage generation unit that generates a reference voltage, a detection processing unit that generates a first detection value of the voltage or current supplied from the power system to the power equipment using the reference voltage, a correction value setting unit that sets a correction value, a correction processing unit that corrects the first detection value according to the correction value, and a control signal generation unit that generates a control signal for controlling a circuit breaker that switches between supplying and cutting off power from the power system to the power equipment according to the second detection value processed by the correction processing unit, wherein the correction value setting unit sets the correction value to a value corresponding to the difference between the reference voltage and the target value when the reference voltage is a value within a correction range that includes a target value, and sets the correction value to a value indicating no correction of the first detection value when the reference voltage is a value outside the correction range.

[0006] A protection and control system according to one embodiment of the present disclosure comprises a circuit breaker that switches between supplying and cutting off power from a power system to power equipment, a protective relay device that generates a control signal, and a circuit breaker control device that controls the circuit breaker in response to the control signal. The protective relay device comprises a reference voltage generation unit that generates a reference voltage, a detection processing unit that generates a first detection value of the voltage or current supplied from the power system to the power equipment using the reference voltage, a correction value setting unit that sets a correction value, a correction processing unit that corrects the first detection value in response to the correction value, and a control signal generation unit that generates the control signal in response to a second detection value after processing by the correction processing unit. When the reference voltage is a value within a correction range including a target value, the correction value setting unit sets the correction value to a value corresponding to the difference between the reference voltage and the target value, and when the reference voltage is a value outside the correction range, the correction value sets the correction value to a value indicating no correction of the first detection value.

[0007] A circuit breaker control method according to one embodiment of the present disclosure is a circuit breaker control method realized by a computer system, which includes generating a reference voltage, generating a first detection value of a voltage or current supplied from a power system to a power equipment using the reference voltage, setting a correction value, correcting the first detection value according to the correction value, and generating a control signal for controlling a circuit breaker that switches between supplying and cutting off power from the power system to the power equipment according to a second detection value processed by the correction processing unit, wherein, in setting the correction value, if the reference voltage is a numerical value within a correction range including a target value, the correction value is set to a numerical value corresponding to the difference between the reference voltage and the target value, and if the reference voltage is a numerical value outside the correction range, the correction value is set to a numerical value indicating no correction of the first detection value. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram illustrating the configuration of a protection and control system according to an embodiment. [Figure 2] FIG. 2 is a block diagram illustrating a functional configuration of a control unit. [Figure 3] FIG. 10 is an explanatory diagram of the operation of a correction value setting unit. [Figure 4] 10 is a flowchart illustrating a specific procedure of a correction process. [Figure 5] 10 is a specific example of an operation executed by the control device. [Figure 6] 10 is a specific example of an operation executed by the control device. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The following description of an embodiment of the present disclosure will be given with reference to the accompanying drawings. Note that the embodiment described below is an exemplary embodiment that may be envisioned when implementing the present disclosure. Therefore, the scope of the present disclosure is not limited to the embodiment exemplified below.

[0010] A: Embodiment 1 is a block diagram illustrating the configuration of a protection and control system 100 according to an embodiment of the present disclosure. The protection and control system 100 is a system that protects power equipment 12 by controlling power (three-phase AC power) supplied from a power grid 10 via a distribution line 11 to the power equipment 12.

[0011] The power system 10 is, for example, a distribution system or a transmission system for supplying electric power generated by a power generation facility (not shown) such as a thermal power plant or a nuclear power plant to consumers such as business facilities or ordinary homes.

[0012] The power facility 12 is a power receiving facility that operates using AC power supplied from the power grid 10 via the distribution line 11. Examples of the power facility 12 include a substation facility that converts AC power, or a power transmission facility that transmits AC power to other facilities.

[0013] The protection and control system 100 includes a circuit breaker 22 and a control system 23. The circuit breaker 22 is installed between the power system 10 and the power equipment 12. The circuit breaker 22 is a switch that switches between supplying and cutting off power from the power system 10 to the power equipment 12. In other words, the circuit breaker 22 is controlled to either a conductive state in which power is supplied from the power system 10 to the power equipment 12, or a cut-off state in which the supply of power to the power equipment 12 is cut off.

[0014] The control system 23 is a system that controls the circuit breaker 22. Specifically, the control system 23 controls the circuit breaker 22 to either a conductive state or a cut-off state depending on the state of the power system 10. That is, the control system 23 controls the circuit breaker 22 to a cut-off state when an abnormality occurs in the power system 10, and maintains the circuit breaker 22 in a conductive state when the power system 10 is normal. As can be understood from the above explanation, the protection and control system 100 protects the power equipment 12 from an abnormality in the power system 10.

[0015] 1, the control system 23 includes a protective relay device 24 and a circuit breaker control device 25. The protective relay device 24 is a computer system that generates a control signal Da in accordance with the state of the power system 10. The circuit breaker control device 25 controls the circuit breaker 22 in accordance with the control signal Da.

[0016] The protective relay device 24 includes a reference voltage generating unit 30, a detection processing unit 50, and a control unit 60. The protective relay device 24 may be realized by a single device, or may be realized by multiple devices configured separately from each other. For example, one or more elements of the reference voltage generating unit 30 and the detection processing unit 50 may be configured separately as external devices of the protective relay device 24.

[0017] The reference voltage generating unit 30 is a regulator that generates a predetermined reference voltage Vref. The reference voltage Vref is a DC voltage used as a reference in each element of the protective relay device 24. The reference voltage generating unit 30 generates the reference voltage Vref, for example, by stepping down the power supply voltage supplied from a power supply circuit (not shown). Ideally, the reference voltage Vref is a constant voltage, but in reality, it may fluctuate over time due to fluctuations in the power supply voltage, etc. For example, the reference voltage Vref may be accompanied by a fluctuation component (drift component) caused by temperature changes.

[0018] The detection processing unit 50 is an electric circuit that generates a current detection value X1(t), a voltage detection value Y1(t), and a reference voltage R(t) using a reference voltage Vref. The current detection value X1(t) is a measured value of the current supplied from the power system 10 to the power equipment 12 (i.e., the current in the power distribution line 11). The voltage detection value Y1(t) is a measured value of the voltage supplied from the power system 10 to the power equipment 12 (i.e., the voltage in the power distribution line 11). The reference voltage R(t) is a measured value of the reference voltage Vref. The current detection value X1(t), the voltage detection value Y1(t), and the reference voltage R(t) are repeatedly generated for each time t that is equally spaced on the time axis. That is, the detection processing unit 50 generates a time series of the current detection value X1(t), a time series of the voltage detection value Y1(t), and a time series of the reference voltage R(t).

[0019] 1, the detection processing unit 50 of this embodiment includes a power conversion unit 40, a signal processing unit 51, and an A / D conversion unit 52. Each element of the detection processing unit 50 operates using the reference voltage Vref generated by the reference voltage generation unit 30.

[0020] The power conversion unit 40 converts the power supplied from the power system 10 to the distribution line 11. The power conversion unit 40 includes a current transformer 41 and a voltage transformer 42. Note that one of the current transformer 41 and the voltage transformer 42 may be omitted.

[0021] The current transformer 41 is an auxiliary current transformer that generates an observation signal Ax corresponding to the current supplied from the power system 10. The observation signal Ax is a signal that fluctuates to a signal level corresponding to the current in the distribution line 11. The current transformer 41 generates the observation signal Ax by detecting the current flowing from the distribution line 11 to the detector coil 411 using a resistive element 412 (shunt resistor). A reference voltage Vref is supplied to one end of the detector coil 411 and one end of the resistive element 412. In other words, the observation signal Ax is an analog signal corresponding to the current based on the reference voltage Vref. As explained above, the current transformer 41 converts the current supplied from the power system 10 into the observation signal Ax using the reference voltage Vref. The current transformer 41 can also be expressed as a current detection unit that detects the current supplied from the power system 10 to the power equipment 12.

[0022] The transformer 42 is an auxiliary transformer that generates an observation signal Ay corresponding to the voltage supplied from the power system 10. The observation signal Ay is a signal that is set to a signal level corresponding to the voltage of the distribution line 11. The transformer 42 generates the observation signal Ay by converting the voltage of the distribution line 11 to a low voltage or a high voltage using a primary coil 421 and a secondary coil 422. A reference voltage Vref is supplied to one end of the secondary coil 422. In other words, the observation signal Ay is an analog signal corresponding to a voltage based on the reference voltage Vref. As described above, the transformer 42 converts the voltage supplied from the power system 10 into the observation signal Ay using the reference voltage Vref. The transformer 42 can also be expressed as a voltage detection unit that detects the voltage supplied from the power system 10 to the power equipment 12. The observation signals Ax and Ay are examples of a "first signal."

[0023] The signal processing unit 51 is an analog filter that performs filtering on the observation signal Ax and the observation signal Ay. Specifically, the signal processing unit 51 generates the observation signal Bx by filtering the observation signal Ax, and generates the observation signal By by filtering the observation signal Ay. The filtering performed by the signal processing unit 51 is, for example, low-pass filtering that suppresses (ideally removes) high-frequency noise components. That is, the signal processing unit 51 generates the observation signal Bx by suppressing the high-frequency components of the observation signal Ax, and generates the observation signal By by suppressing the high-frequency components of the observation signal Ay. A reference voltage Vref is used for the filtering by the signal processing unit 51. For example, the frequency response (e.g., cutoff frequency) of the signal processing unit 51 is set according to the reference voltage Vref.

[0024] The A / D converter 52 generates digital detected current values ​​X1(t) and detected voltage values ​​Y1(t) through A / D conversion. Specifically, the A / D converter 52 generates a time series of detected current values ​​X1(t) through A / D conversion of the observation signal Bx, and generates a time series of detected voltage values ​​Y1(t) through A / D conversion of the observation signal By. The conversion characteristics (e.g., resolution) of the A / D converter 52 are set according to the power supply voltage.

[0025] In this embodiment, the A / D converter 52 performs A / D conversion on the observation signal Bx and the observation signal By, and also generates a reference voltage R(t) by A / D conversion on the reference voltage Vref. The A / D converter 52 may include a separate circuit for performing A / D conversion on the observation signal Bx, a circuit for performing A / D conversion on the observation signal By, and a circuit for performing A / D conversion on the reference voltage Vref. The A / D converter 52 may also be mounted on the control unit 60.

[0026] As explained above, each element of the detection processing unit 50 (current transformer 41, transformer 42, signal processing unit 51) operates using the reference voltage Vref generated by the reference voltage generating unit 30. Therefore, if the reference voltage Vref fluctuates, errors may occur in the current detection value X1(t) and the voltage detection value Y1(t).

[0027] The control unit 60 controls each element of the protective relay device 24. Specifically, the control unit 60 includes a control device 61 and a storage device 62. The current detection value X1(t), voltage detection value Y1(t), and reference voltage R(t) generated by the A / D conversion unit 52 are supplied to the control device 61.

[0028] The control device 61 is composed of one or more processors that control each element of the control unit 60. Specifically, the control device 61 is composed of one or more types of processors, such as a CPU (Central Processing Unit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or an ASIC (Application Specific Integrated Circuit). The storage device 62 is one or more memories that store programs executed by the control device 61 and data used by the control device 61. The storage device 62 is composed of a known storage medium, such as a semiconductor storage medium.

[0029] Fig. 2 is a block diagram illustrating an example of the functional configuration of the control unit 60. As illustrated in Fig. 2, the control device 61 executes a program stored in the storage device 62 to realize a plurality of functions (a correction value setting unit 81, a correction processing unit 82, and a control signal generating unit 83).

[0030] The correction value setting unit 81 sets a correction value Qx(t) and a correction value Qy(t). The correction value Qx(t) is a variable applied to correct the detected current value X1(t). The correction value Qy(t) is a variable applied to correct the detected voltage value Y1(t). The correction values ​​Qx(t) and Qy(t) are generated sequentially at each time t in parallel with the operation of the detection processing unit 50.

[0031] The correction processing unit 82 corrects the detected current value X1(t) and the detected voltage value Y1(t). Specifically, the correction processing unit 82 corrects the detected current value X1(t) according to a correction value Qx(t). For example, the correction processing unit 82 calculates a corrected detected current value X2(t) by subtracting the correction value Qx(t) from the detected current value X1(t) (X2(t) = X1(t) - Qx(t)). The correction processing unit 82 also corrects the detected voltage value Y1(t) according to the correction value Qy(t). For example, the correction processing unit 82 calculates a corrected detected voltage value Y2(t) by subtracting the correction value Qy(t) from the detected voltage value Y1(t) (Y2(t) = Y1(t) - Qy(t)). The uncorrected current detection value X1(t) and voltage detection value Y1(t) are examples of the "first detection value," and the corrected current detection value X2(t) and voltage detection value Y2(t) are examples of the "second detection value."

[0032] 3 is an explanatory diagram of the process in which the correction value setting unit 81 sets the correction values ​​Qx(t) and Qy(t). The target value R0 illustrated in FIG. 3 is an ideal or theoretical value of the reference voltage Vref. A range of a predetermined width (hereinafter referred to as the "correction range C") including the target value R0 is illustrated in FIG. 3.

[0033] The correction range C is a numerical range between a first limit value L1 and a second limit value L2. The first limit value L1 is a predetermined upper limit value located on the positive side of the target value R0 (L1 > R0). The second limit value L2 is a predetermined lower limit value located on the negative side of the target value R0 (L2 < R0). The difference between the first limit value L1 and the target value R0 (L1 - R0) is equal to the difference between the target value R0 and the second limit value L2 (R0 - L2). That is, the target value R0 corresponds to the midpoint of the correction range C.

[0034] The control signal generation unit 83 in FIG. 2 generates a control signal Da according to the current detection value X2(t) and the voltage detection value Y2(t) after the processing by the correction processing unit 82. The control signal Da is a signal for instructing the control of the circuit breaker 22 by the circuit breaker control device 25. The control signal generation unit 83 outputs the control signal Da to the circuit breaker control device 25.

[0035] Specifically, the control signal generation unit 83 calculates the power of the power distribution line 11 (hereinafter referred to as "observed power") by multiplying the current detection value X2(t) and the voltage detection value Y2(t), and generates the control signal Da according to whether the observed power exceeds a threshold value. For example, when the observed power exceeds the threshold value, the control signal generation unit 83 outputs a control signal Da indicating an abnormality of the power system 10 to the circuit breaker control device 25.

[0036] The control signal Da is a signal for the circuit breaker control device 25 to control the circuit breaker 22 to the tripped state. Therefore, when an abnormality occurs in the power system 10, the circuit breaker 22 transitions to the tripped state, and as a result, the power supply from the power system 10 to the power facility 12 is cut off. When the observed power is below the threshold value, the control signal generation unit 83 does not output the control signal Da to the circuit breaker control device 25. As described above, the control signal generation unit 83 also functions as an element for determining the presence or absence of an abnormality in the power system 10.

[0037] FIG. 4 is a flowchart of a process (hereinafter referred to as "correction process") executed by the control device 61. For example, triggered by an interrupt that occurs at a predetermined cycle, the correction process is executed for each time t on the time axis.

[0038] When the correction process starts, the correction value setting unit 81 determines whether the reference voltage R(t) is a value within the correction range C (S1). If the reference voltage R(t) is a value within the correction range C (S1: YES), the correction value setting unit 81 sets the correction values ​​Qx(t) and Qy(t) to values ​​corresponding to the difference between the reference voltage R(t) and the target value R0 (S2).

[0039] Specifically, the correction value setting unit 81 sets the correction values ​​Qx(t) and Qy(t) according to the difference (R(t)-R0) between the reference voltage R(t) and the target value R0. For example, the correction value Qx(t) is calculated by multiplying the difference (R(t)-R0) by a predetermined coefficient αx (Qx(t)=αx(R(t)-R0)). The correction value Qy(t) is calculated by multiplying the difference (R(t)-R0) by a predetermined coefficient αy (Qy(t)=αy(R(t)-R0)).

[0040] Once the correction values ​​Qx(t) and Qy(t) have been set using the above procedure, the correction processing unit 82 corrects the current detection value X1(t) using the correction value Qx(t) and corrects the voltage detection value Y1(t) using the correction value Qy(t) (S3).

[0041] On the other hand, if the reference voltage R(t) is a value outside the correction range C (S1: NO), the correction value setting unit 81 sets the correction values ​​Qx(t) and Qy(t) to values ​​that represent no correction (S4). That is, for example, the correction values ​​Qx(t) and Qy(t) are set to 0.

[0042] When the correction value Qx(t) is set to 0, the correction processing unit 82 outputs the detected current value X1(t) as the detected current value X2(t) without correcting it (S5). Similarly, when the correction value Qy(t) is set to 0, the correction processing unit 82 outputs the detected voltage value Y1(t) as the detected voltage value Y2(t) without correcting it (S5).

[0043] After the above processes (S3, S5) are performed, the control signal generator 83 determines whether or not an abnormality exists in the power grid 10 based on the detected current value X2(t) and the detected voltage value Y2(t) after processing by the correction processor 82 (S6). Specifically, the control signal generator 83 determines that an abnormality exists when the observed power corresponding to the detected current value X2(t) and the detected voltage value Y2(t) exceeds a threshold, and determines that an abnormality does not exist when the observed power is below the threshold. If the control signal generator 83 determines that an abnormality exists in the power grid 10 (S6: YES), the control signal generator 83 generates a control signal Da and outputs it to the circuit breaker control device 25 (S7). On the other hand, if the control signal generator 83 determines that an abnormality does not exist in the power grid 10 (S6: NO), the control signal generator 83 does not generate and output the control signal Da (S7). Note that in the above description, it was determined that an abnormality does not exist when the observed power is below the threshold. However, it may also be determined that an abnormality exists when the observed power is below the threshold, such as when the observed power decreases due to a power outage.

[0044] 5 and 6 show specific examples of operations performed by the control device 61. The voltage V(t) in FIGS. 5 and 6 is the actual voltage (i.e., true value) of the distribution line 11. In FIGS. 5 and 6, it is assumed for the sake of convenience that the voltage V(t) of the distribution line 11 is maintained constant. Therefore, ideally, the detected voltage value Y1(t) is maintained constant, but in reality, as illustrated in FIGS. 5 and 6, the detected voltage value Y1(t) fluctuates over time due to fluctuations in the reference voltage Vref(R(t)).

[0045] In FIG. 5, the reference voltage R(t) is a value within the correction range C. Therefore, the correction value Qy(t) is set to a value corresponding to the difference (R(t) - R0) between the reference voltage R(t) and the target value R0. As a result of correcting the detected voltage value Y1(t) using the correction value Qy(t) described above, the corrected detected voltage value Y2(t) is maintained at a constant value over the entire period, just like the actual voltage V(t).

[0046] On the other hand, in the situation illustrated in FIG. 6, the reference voltage R(t) is maintained within the correction range C during the period T12 from time t1 to time t2 and during the period T34 from time t3 to time t4. Therefore, during the periods T12 and T34, the correction value Qy(t) is set to a value corresponding to the difference (R(t) - R0) between the reference voltage R(t) and the target value R0. On the other hand, during the period T23 from time t2 to time t3, the reference voltage R(t) is outside the correction range C. Specifically, the reference voltage R(t) exceeds the first limit value L1. Therefore, during the period T23, the correction value Qy(t) is set to 0, which indicates no correction (Qy(t) = 0).

[0047] As a result of correcting the detected voltage value Y1(t) using the correction value Qy(t) described above, the corrected detected voltage value Y2(t) is maintained at a constant value during periods T12 and T34. Meanwhile, during period T23, the detected voltage value Y1(t) is set as the detected voltage value Y2(t) without being corrected. Therefore, as illustrated in FIG. 6, the detected voltage value Y2(t) fluctuates over time during period T23 in conjunction with the reference voltage R(t). While the above description focuses on the correction of the detected voltage value Y1(t), the correction of the detected current value X1(t) is also performed in a similar manner.

[0048] The correction range C is set to a range of generally expected fluctuations in the reference voltage R(t). That is, fluctuations in the reference voltage R(t) due to general factors, such as temperature changes, occur within the correction range C. On the other hand, if the reference voltage R(t) exceeds the correction range C, it is assumed that the fluctuations in the reference voltage R(t) are due to special factors other than general factors. In this embodiment, if the reference voltage R(t) is a value outside the correction range C, the detected current value X1(t) and the detected voltage value Y1(t) are not corrected. Therefore, by observing the detected current value X2(t) and the detected voltage value Y2(t), an abnormality in the reference voltage Vref due to special factors can be detected.

[0049] The circuit breaker control device 25 in Fig. 1 controls the circuit breaker 22 in response to a control signal Da supplied from the protective relay device 24. Specifically, when the circuit breaker control device 25 receives a control signal Da indicating an abnormality in the power system 10 from the control signal generation unit 83, it outputs a tripping signal Db to the circuit breaker 22 to control the circuit breaker 22 to the cutoff state (i.e., trip) the circuit breaker 22. Therefore, when an abnormality occurs in the power system 10, the circuit breaker 22 transitions to the cutoff state, and as a result, the supply of power from the power system 10 to the power equipment 12 is cut off. On the other hand, when the circuit breaker control device 25 does not receive a control signal Da from the control signal generation unit 83, it does not send the tripping signal Db to the circuit breaker 22. That is, the circuit breaker control device 25 maintains the circuit breaker 22 in the conductive state.

[0050] In the above description, the circuit breaker 22 is controlled in accordance with the observed power, but the method of controlling the circuit breaker 22 is not limited to the above example. For example, a configuration in which the circuit breaker 22 is controlled in accordance with only the current detection value X2(t) or only the voltage detection value Y2(t) is also possible. Furthermore, the circuit breaker control device 25 may control the circuit breaker 22 in accordance with various evaluation indexes calculated by applying one or both of the current detection value X2(t) and the voltage detection value Y2(t).

[0051] As described above, in this embodiment, when the reference voltage R(t) is within the correction range C, the detected current value X1(t) is corrected using the correction value Qx(t) corresponding to the difference between the reference voltage R(t) and the target value R0, and the detected voltage value Y1(t) is corrected using the correction value Qy(t). Therefore, the influence of fluctuations in the reference voltage R(t) within the correction range C (e.g., fluctuations due to general factors) is reduced by correcting the detected current value X1(t) and the detected voltage value Y1(t). On the other hand, when fluctuations in the reference voltage R(t) exceed the correction range C, the correction values ​​Qx(t) and Qy(t) are set to a value (=0) indicating no correction, and as a result, the detected current value X1(t) and the detected voltage value Y1(t) are not corrected. Therefore, fluctuations in the reference voltage Vref(R(t)) due to special factors can be properly detected.

[0052] In this embodiment, the correction range C is distributed on both the positive and negative sides of the target value R0. Therefore, the influence of both fluctuations in which the reference voltage R(t) exceeds the target value R0 and fluctuations in which the reference voltage R(t) falls below the target value R0 can be reduced from the detected current value X1(t) and the detected voltage value Y1(t).

[0053] In this embodiment, it is possible to correct errors in the detected current value X1(t) and the detected voltage value Y1(t) caused by fluctuations in the reference voltage Vref used by the detection processing unit 50. Specifically, errors accompanying the detected current value X1(t) and the detected voltage value Y1(t) caused by fluctuations in the reference voltage Vref in the current transformer 41, the transformer 42, the signal processing unit 51, and the A / D conversion unit 52 are corrected.

[0054] B: Modified example Specific modified embodiments that can be added to the embodiments exemplified above are shown below. Two or more embodiments arbitrarily selected from the following examples may be combined as appropriate within the scope of not being mutually contradictory.

[0055] (1) In the above-described embodiment, the detection processing unit 50 generates the detected current value X1(t) and the detected voltage value Y1(t). However, the detection processing unit 50 may generate either the detected current value X1(t) or the detected voltage value Y1(t). Similarly, in the above-described embodiment, the correction processing unit 82 corrects both the detected current value X1(t) and the detected voltage value Y1(t). However, the correction processing unit 82 may correct either the detected current value X1(t) or the detected voltage value Y1(t). Therefore, the correction value setting unit 81 may set only one of the correction value Qx(t) and the correction value Qy(t).

[0056] (2) In the above-described embodiment, the target value R0 is a fixed value, but the target value R0 may be a variable value that changes over time. Furthermore, in the above-described embodiment, the correction range C is a fixed-width range with the target value R0 as its midpoint, but the correction range C may be a variable-width range that changes over time. For example, a configuration in which the first limit value L1 changes over time or a configuration in which the second limit value L2 changes over time is conceivable.

[0057] (3) In the above-described embodiment, the target value R0 corresponds to the midpoint of the correction range C. However, the relationship between the target value R0 and the correction range C is not limited to the above example. For example, the difference (L1-R0) between the first limit value L1 and the target value R0 may be different from the difference (R0-L2) between the target value R0 and the second limit value L2. For example, the difference (L1-R0) may be greater than the difference (R0-L2), or the difference (L1-R0) may be less than the difference (R0-L2).

[0058] (4) As described above, the functions of the protection relay device 24 according to each of the above embodiments are realized by cooperation between one or more processors constituting the control device 61 and the program stored in the storage device 62. The programs exemplified above can be provided in a form stored in a computer-readable recording medium and installed on a computer. The recording medium is, for example, a non-transitory recording medium, such as an optical recording medium (optical disk) such as a CD-ROM, but also includes any known type of recording medium, such as a semiconductor recording medium or a magnetic recording medium. Note that a non-transitory recording medium includes any recording medium other than a transient, propagating signal, and does not exclude volatile recording media. Furthermore, in a configuration in which a distribution device distributes a program via a communication network, the recording medium storing the program in the distribution device corresponds to the non-transitory recording medium described above.

[0059] (5) The term "nth" (n is a natural number) in this application is used only as a formal and convenient label to distinguish each element in the description and does not have any substantive meaning. Therefore, there is no room for restrictive interpretation of the position or order of each element based on the term "nth."

[0060] C: Notes From the above-described exemplary embodiments, the following configurations can be understood, for example.

[0061] A protective relay device according to one aspect (aspect 1) of the present disclosure includes a reference voltage generation unit that generates a reference voltage; a detection processing unit that uses the reference voltage to generate a first detection value of a voltage or current supplied from a power grid to power equipment; a correction value setting unit that sets a correction value; a correction processing unit that corrects the first detection value in accordance with the correction value; and a control signal generation unit that generates a control signal for controlling a circuit breaker that switches between supplying and cutting off power from the power grid to the power equipment in accordance with a second detection value processed by the correction processing unit. When the reference voltage is within a correction range that includes a target value, the correction value setting unit sets the correction value to a value corresponding to the difference between the reference voltage and the target value. When the reference voltage is outside the correction range, the correction value setting unit sets the correction value to a value indicating no correction of the first detection value. In the above aspect, when the reference voltage is within the correction range, the first detection value is corrected by the correction value corresponding to the difference between the reference voltage and the target value. Therefore, the influence of fluctuations in the reference voltage within the correction range (e.g., fluctuations due to general factors) is reduced by the correction of the first detection value. On the other hand, if the reference voltage fluctuates beyond the compensation range, the compensation value is set to a value indicating no compensation, and as a result, the first detection value is not compensated. Therefore, fluctuations in the reference voltage due to special factors can be properly detected.

[0062] In a specific example (Aspect 2) of Aspect 1, the correction range is a range between a first limit value located on the positive side of the target value and a second limit value located on the negative side of the target value. In the above aspect, the correction range is distributed on both the positive and negative sides of the target value. Therefore, the influence of both fluctuations in the reference voltage above the target value and fluctuations in the reference voltage below the target value can be reduced from the detected value.

[0063] In a specific example (Aspect 3) of Aspect 1 or Aspect 2, the detection processing unit includes a current transformer that converts the current supplied from the power grid into a first signal corresponding to a current based on the reference voltage. According to the above aspect, it is possible to correct an error in the first detection value caused by fluctuations in the reference voltage used by the current transformer.

[0064] In a specific example (Aspect 4) of any one of Aspects 1 to 3, the detection processing unit includes a transformer that converts the voltage supplied from the power grid into a first signal corresponding to a voltage based on the reference voltage. According to the above aspect, it is possible to correct an error in the first detection value caused by fluctuations in the reference voltage used by the transformer.

[0065] In a specific example (Aspect 5) of Aspect 3 or Aspect 4, the detection processing section includes a signal processing section that generates a second signal by performing filtering on the first signal using the reference voltage. According to the above aspect, it is possible to correct an error in the first detection value caused by fluctuations in the reference voltage used by the signal processing section for filtering.

[0066] A protection and control system according to one aspect (aspect 6) of the present disclosure comprises a circuit breaker that switches between supplying and cutting off power from a power system to power equipment, a protective relay device that generates a control signal, and a circuit breaker control device that controls the circuit breaker in response to the control signal. The protective relay device comprises a reference voltage generation unit that generates a reference voltage, a detection processing unit that generates a first detection value of the voltage or current supplied from the power system to the power equipment using the reference voltage, a correction value setting unit that sets a correction value, a correction processing unit that corrects the first detection value in response to the correction value, and a control signal generation unit that generates the control signal in response to a second detection value after processing by the correction processing unit. When the reference voltage is a value within a correction range including a target value, the correction value setting unit sets the correction value to a value corresponding to the difference between the reference voltage and the target value, and when the reference voltage is a value outside the correction range, the correction value sets the correction value to a value indicating no correction of the first detection value.

[0067] A circuit breaker control method according to one aspect (aspect 7) of the present disclosure is a circuit breaker control method realized by a computer system, which includes generating a reference voltage, generating a first detection value of a voltage or current supplied from a power system to a power equipment using the reference voltage, setting a correction value, correcting the first detection value according to the correction value, and generating a control signal for controlling a circuit breaker that switches between supplying and cutting off power from the power system to the power equipment according to the corrected second detection value, wherein, in setting the correction value, if the reference voltage is a value within a correction range including a target value, the correction value is set to a value corresponding to the difference between the reference voltage and the target value, and if the reference voltage is a value outside the correction range, the correction value is set to a value indicating no correction of the first detection value. [Explanation of symbols]

[0068] 100...protection and control system, 10...power system, 11...distribution line, 12...power equipment, 22...circuit breaker, 23...control system, 24...protective relay device, 25...circuit breaker control device, 30...reference voltage generation unit, 40...power conversion unit, 41...current transformer, 411...voltage detection coil, 412...resistance element, 42...transformer, 421...primary coil, 422...secondary coil, 50...detection processing unit, 51...signal processing unit, 52...A / D conversion unit, 60...control unit, 61...control device, 62...storage device, 81...correction value setting unit, 82...correction processing unit.

Claims

1. a reference voltage generating unit that generates a reference voltage; a detection processing unit that generates a first detection value of a voltage or a current supplied from the power grid to the power equipment using the reference voltage; a correction value setting unit that sets a correction value; a correction processing unit that corrects the first detection value in accordance with the correction value; a control signal generation unit that generates a control signal for controlling a circuit breaker that switches between supplying and cutting off power from the power system to the power equipment in accordance with the second detection value processed by the correction processing unit, The correction value setting unit When the reference voltage is a value within a correction range including a target value, the correction value is set to a value corresponding to a difference between the reference voltage and the target value; When the reference voltage is a value outside the correction range, the correction value is set to a value indicating that the first detection value is not corrected. Protective relay devices.

2. The correction range is a range between a first limit value located on the positive side of the target value and a second limit value located on the negative side of the target value. The protective relay device of claim 1.

3. The detection processing unit a current transformer that converts the current supplied from the power system into a first signal corresponding to a current based on the reference voltage; The protective relay device of claim 1.

4. The detection processing unit a transformer that converts the voltage supplied from the power system into a first signal corresponding to a voltage based on the reference voltage The protective relay device of claim 1.

5. The detection processing unit includes a signal processing unit that generates a second signal by performing a filter process on the first signal using the reference voltage. The protective relay device according to claim 3 or 4.

6. a circuit breaker that switches between supplying and cutting off power from the power system to the power equipment; a protective relay device that generates a control signal; a circuit breaker control device that controls the circuit breaker in response to the control signal, The protective relay device includes: a reference voltage generating unit that generates a reference voltage; a detection processing unit that generates a first detection value of a voltage or a current supplied from the power grid to the power equipment using the reference voltage; a correction value setting unit that sets a correction value; a correction processing unit that corrects the first detection value in accordance with the correction value; a control signal generating unit that generates the control signal in response to the second detection value after processing by the correction processing unit, The correction value setting unit When the reference voltage is a value within a correction range including a target value, the correction value is set to a value corresponding to a difference between the reference voltage and the target value; When the reference voltage is a value outside the correction range, the correction value is set to a value indicating that the first detection value is not corrected. Protection and control systems.

7. generating a reference voltage; generating a first detected value of a voltage or a current supplied from the power grid to the power equipment using the reference voltage; Setting a correction value; correcting the first detection value in accordance with the correction value; generating a control signal for controlling a circuit breaker that switches between supplying and cutting off power from the power system to the power facility in accordance with the corrected second detection value; A circuit breaker control method implemented by a computer system including: In setting the correction value, When the reference voltage is a value within a correction range including a target value, the correction value is set to a value corresponding to a difference between the reference voltage and the target value; When the reference voltage is a value outside the correction range, the correction value is set to a value indicating that the first detection value is not corrected. Circuit breaker control method.

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