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JP-7856230-B2 - Insulation monitoring device, operation test system for insulation monitoring device, operation test method for insulation monitoring device, and operation test program for insulation monitoring device

JP7856230B2JP 7856230 B2JP7856230 B2JP 7856230B2JP-7856230-B2

Inventors

  • 斉藤 篤
  • 臼井 千春
  • 永井 聡
  • 茂木 達哉

Assignees

  • 佐鳥電機株式会社

Dates

Publication Date
20260511
Application Date
20220120

Claims (10)

  1. A reference voltage detection unit that detects the voltage applied between any two phases of the monitored AC circuit and acquires it as a reference voltage, A test current output unit capable of outputting a test current synchronized with the aforementioned reference voltage to a test current output line, A leakage current detection unit that acquires the measured leakage current based on the current detection results of the monitored circuit and the test current output line, A calculation unit that generates information regarding the detection accuracy of the leakage current detection unit based on a first measured leakage current acquired by the leakage current detection unit when the test current is not being output, and a second measured leakage current acquired by the leakage current detection unit when the test current is being output. A phase difference calculation unit for detecting the phase difference of the measured leakage current with respect to the reference voltage, Equipped with, The leakage current detection unit calculates the effective value of the first measured leakage current and the effective value of the second measured leakage current. The calculation unit calculates the change in leakage current by performing a vector operation on the first measured leakage current and the second measured leakage current based on the first measured phase difference detected by the phase difference calculation unit for the first measured leakage current, the second measured phase difference detected by the phase difference calculation unit for the second measured leakage current, the effective value of the first measured leakage current, and the effective value of the second measured leakage current. Insulation monitoring device.
  2. The aforementioned arithmetic unit, The terminal measurement current, which is the result of detecting the test current by the measurement terminal, is obtained from the measurement terminal. Based on the terminal measurement current and the change in leakage current, the detection accuracy of the leakage current detection unit is diagnosed. The insulation monitoring device according to claim 1.
  3. The calculation unit diagnoses the detection accuracy of the leakage current detection unit based on the output value of the test current and the change in the leakage current. The insulation monitoring device according to claim 1 or 2.
  4. The calculation unit calculates the phase difference of the leakage current change with respect to the reference voltage. An insulation monitoring device according to any one of claims 1 to 3.
  5. The calculation unit calculates a vector component of the leakage current change that is parallel to the test current. An insulation monitoring device according to any one of claims 1 to 4.
  6. The system further includes a display unit that displays the change in leakage current. An insulation monitoring device according to any one of claims 1 to 5.
  7. The insulation monitoring device according to claim 6, wherein the display unit displays the phase difference of the leakage current change with respect to the reference voltage.
  8. A reference voltage detection unit that detects the voltage applied between any two phases of the monitored AC circuit and acquires it as a reference voltage, A test current output unit capable of outputting a test current synchronized with the aforementioned reference voltage to a test current output line, A leakage current detection unit detects the leakage current, including the test current, flowing through the monitored circuit and the test current output line, and acquires it as a measured leakage current. A calculation unit that generates information regarding the detection accuracy of the leakage current detection unit based on a first measured leakage current detected by the leakage current detection unit when the test current is not being output, and a second measured leakage current detected by the leakage current detection unit when the test current is being output. A phase difference calculation unit for detecting the phase difference of the measured leakage current with respect to the reference voltage, Equipped with, The leakage current detection unit calculates the effective value of the first measured leakage current and the effective value of the second measured leakage current. The calculation unit calculates the change in leakage current by performing a vector operation on the first measured leakage current and the second measured leakage current based on the first measured phase difference detected by the phase difference calculation unit for the first measured leakage current, the second measured phase difference detected by the phase difference calculation unit for the second measured leakage current, the effective value of the first measured leakage current, and the effective value of the second measured leakage current. An operational test system for insulation monitoring devices.
  9. An operational test method in which a computer generates information regarding the detection accuracy of leakage current in an insulation monitoring device that detects leakage current in an AC circuit under monitoring, A reference voltage detection step, which detects the voltage applied between any two phases of the monitored circuit and acquires it as a reference voltage, A first measured leakage current acquisition step, which involves detecting the leakage current flowing through the monitored electrical circuit and acquiring it as a first measured leakage current, A test current output step that outputs a test current synchronized with the aforementioned reference voltage to a test current output line, A second measured leakage current acquisition step, which involves detecting the leakage current, including the test current, flowing through the monitored circuit and the test current output line when the aforementioned test current is being output, and acquiring it as a second measured leakage current; A calculation step that generates information regarding the detection accuracy based on the first measured leakage current and the second measured leakage current, A phase difference calculation step for detecting the phase difference of the first measured leakage current with respect to the reference voltage and the phase difference of the second measured leakage current with respect to the reference voltage , Equipped with, The first measurement leakage current acquisition step calculates the effective value of the first measurement leakage current, The second measurement leakage current acquisition step calculates the effective value of the second measurement leakage current, The calculation step calculates the change in leakage current by performing a vector operation on the first measured leakage current and the second measured leakage current based on the first measured phase difference detected in the phase difference calculation step for the first measured leakage current, the second measured phase difference detected in the phase difference calculation step for the second measured leakage current, the effective value of the first measured leakage current, and the effective value of the second measured leakage current. Method for testing the operation of an insulation monitoring device.
  10. An operational test program for generating information regarding the detection accuracy of leakage current in an insulation monitoring device that detects leakage current in an AC circuit under monitoring, A reference voltage detection step, which detects the voltage applied between any two phases of the monitored circuit and acquires it as a reference voltage, A first measured leakage current acquisition step, which involves detecting the leakage current flowing through the monitored electrical circuit and acquiring it as a first measured leakage current, A test current output step that outputs a test current synchronized with the aforementioned reference voltage to a test current output line, A second measured leakage current acquisition step, which involves detecting the leakage current, including the test current, flowing through the monitored circuit and the test current output line when the aforementioned test current is being output, and acquiring it as a second measured leakage current; A calculation step that generates information regarding the detection accuracy based on the first measured leakage current and the second measured leakage current, A phase difference calculation step for detecting the phase difference of the first measured leakage current with respect to the reference voltage and the phase difference of the second measured leakage current with respect to the reference voltage , This is achieved by computer, The first measurement leakage current acquisition step includes calculating the effective value of the first measurement leakage current. The second measurement leakage current acquisition step includes calculating the effective value of the second measurement leakage current. The calculation step includes calculating the change in leakage current by performing a vector operation on the first measured leakage current and the second measured leakage current based on the first measured phase difference detected in the phase difference calculation step for the first measured leakage current, the second measured phase difference detected in the phase difference calculation step for the second measured leakage current, the effective value of the first measured leakage current, and the effective value of the second measured leakage current. Operation test program for insulation monitoring device.

Description

This invention relates to an insulation monitoring device, an operation test system for an insulation monitoring device, an operation test method for an insulation monitoring device, and an operation test program for an insulation monitoring device. Insulation monitoring devices, which monitor ground faults in low-voltage circuits, contribute to improving electrical safety levels by continuously monitoring the insulation of low-voltage circuits in high-voltage private facilities. This prevents electric shocks, fires, and power outages caused by leakage current. By law, insulation monitoring devices are required to undergo periodic operational and accuracy (error) tests for their leakage current detection function. To perform these operational and accuracy tests accurately, it is necessary to remove the ZCT (Zero-Stress Transformer) from the circuit being monitored, and working near live parts can be dangerous. While it is possible to shut off the power to the measurement circuit, shutting off customer equipment is practically difficult. In contrast, a test current generator and a test apparatus for insulation monitoring devices have been disclosed that allow for operational and accuracy testing of the insulation monitoring device while the monitored circuit remains live without interrupting the power supply (see Patent Document 1). The test current generator in Patent Document 1 generates a test current that, when added to the resistive current component included in the zero-sequence current, yields a target value based on zero-sequence current detection information, a target value for the resistive current component detected by the insulation monitoring device, and a pre-set reference phase information for identifying the phase of the resistive current component. Japanese Patent Publication No. 2007-285790 This figure shows a system configuration in which an insulation monitoring device according to one embodiment of the present invention is applied to an AC circuit.Figure 1 shows examples of transformer configurations: (a) single-phase three-wire system, (b) three-phase three-wire system (delta connection), and (c) three-phase three-wire system (star connection).This figure shows an example of the display screen during an operational test.This is a block diagram showing the configuration of the arithmetic control unit and the input/output configuration of the operational tests performed by the arithmetic control unit.This figure shows the vector of the leakage current generated in the power line under test when no test current is being output in a single-phase three-wire system.In a single-phase three-wire system, when the test current is output, (a) a diagram showing the vector of the leakage current generated in the power line under test, and (b) a diagram showing the vector of the accurately detected measured leakage current.In a single-phase three-wire system, when the test current is output, (a) a diagram showing the vectors of the generated leakage current in the power line under test and the inaccurately detected measured leakage current, and (b) a diagram showing the vector of the leakage current change portion of the inaccurately detected measured leakage current.This is a diagram showing the decomposition of the leakage current change vector in Figure 7(b) into its orthogonal components.In a three-phase three-wire system (delta connection), (a) a diagram showing the vector of leakage current generated in the measured power line when no test current is output, (b) a diagram showing the leakage current generated in the measured power line when a test current is output, and (c) a diagram showing the measured leakage current and the vector of the change in leakage current detected when a test current is output.In a three-phase three-wire system (star connection), (a) a diagram showing the vector of leakage current generated in the measured power line when no test current is output, (b) a diagram showing the leakage current generated in the measured power line when a test current is output, and (c) a diagram showing the measured leakage current and the vector of the change in leakage current detected when a test current is output.This is a flowchart relating to the operational test routine of the insulation monitoring device in this embodiment.This figure shows a first modified example of the system configuration of an insulation monitoring device in one embodiment of the present invention.This is a flowchart relating to the control routine for the operational test of the first modified example.This is a block diagram of the computer configuration.Hardware configuration block. An embodiment of the present invention will be described below with reference to the drawings. <System Configuration> Figure 1 shows a system configuration in which an insulation monitoring device according to one embodiment of the present invention is applied to an AC circuit. Figure 2 shows examples of the transformer configu