KR960032007A - Insulation monitoring system - Google Patents

Abstract

It provides insulation monitoring system that can measure insulation leakage current of electric circuit to be fed from power source without measuring the insulation current, obtain insulation resistance from measured leakage current, identify insulation deterioration situation, and diagnose insulation.

Superimposed single-phase alternating current or direct current voltage of power frequency on the monitored electric circuit supplied by the power supply, detecting the monitored electric circuit leakage current by this measured voltage, and obtaining the insulation resistance of the monitored electric circuit from this leakage current. Display.

The insulation resistance is monitored in real time without stopping the monitored electrical circuit, and it is possible to easily predict the timing of renewal and inspection in the event of insulation deterioration.

Description

Insulation monitoring system

Since this is an open matter, no full text was included.

1 is a block diagram showing the configuration of Embodiment 1 of the insulation monitoring system according to the present invention;

FIG. 2 is a block diagram showing an internal configuration of a circuit protection device used in the first embodiment shown in FIG.

3 is a block diagram showing the configuration of measurement voltage superimposing means used in Embodiment 1 shown in FIG.

Claims (18)

Measurement voltage superimposing means for superimposing the measured voltage of single-phase alternating current at a frequency different from the power supply frequency via a grounding means to the monitored electric circuit supplied by the power supply, and an unbalanced current detecting means for detecting an unbalanced current flowing through the monitored electric circuit. And leakage current detection means for detecting an active component in the leakage current that is in phase with the measurement voltage and at the same frequency as the measurement voltage in the unbalance current detected by the unbalance current detection means, and the leakage current effective component is integrated. And sensing means for converting into a leakage current digital signal, and sensing control means for monitoring and controlling the wound electrical circuit based on the leakage current digital signal. The leakage current detecting means comprises: means for detecting a component having the same frequency as the measured voltage, and means for synchronously detecting by an output signal of the measured voltage synchronizing signal generating means for outputting a signal synchronized with the measured voltage. Insulation monitoring system, characterized in that. The insulation monitoring system according to claim 1 or 2, wherein the frequency of the measurement voltage is lower than the power supply frequency. The insulation monitoring system according to claim 1 or 2, wherein the frequency of the measurement voltage is any frequency between 150 and 500 Hz higher than the power supply frequency. Measurement voltage superimposition means for superimposing measurement voltages of single-phase alternating currents of two kinds of frequencies different from the power supply frequency via a grounding means to the monitored electric circuit supplied by the power supply, and an unbalance for detecting an unbalanced current flowing through the monitored electric circuit. The current detection means and the unbalanced current detected by the unbalanced current detection means respectively detect a component having the same frequency as each of the measured voltages, and the unbalanced current corresponding to each measured voltage is effective in the leakage current of the monitored electric circuit. Leakage current detection means for calculating a component, calculating means for integrating the leakage current effective component and converting it into a leakage current digital signal, and sensing control means for monitoring and controlling the wound electrical circuit based on the leakage current digital signal. Insulation monitoring system. The insulation monitoring system according to claim 5, wherein the frequencies of the two types of measurement voltages are lower than the power supply frequency. The insulation monitoring system according to claim 5, wherein the frequencies of the two types of measurement voltages are any other frequencies between 150 and 500 Hz higher than the power supply frequency. Measured voltage superimposing means for superimposing a measured voltage of direct current through a grounding means in the monitored electric circuit supplied from the power supply, unbalanced current detecting means for detecting an unbalanced current flowing in the monitored electric circuit, and the unbalanced current detecting means Leakage current detection means for detecting the leakage current of the monitored electric circuit by removing the power source frequency component and the high frequency component from the detected unbalanced current, arithmetic means for converting the leakage current into a leakage current digital signal, and the leakage current digital signal. The insulation monitoring system which consists of sensing control means which monitors and controls the said monitored electric circuit based on this. The insulation monitoring system according to claim 1 or 2, wherein the measurement voltage superimposing means and the leakage current detecting means are controlled by supervisory control means. The method according to claim 1 or 2, wherein the sensing control means has a function of storing a leakage current value for each fixed period, constantly monitoring the change of the leakage current value, and alarming when a preset limit value is exceeded. Insulation monitoring system. The insulation monitoring system according to claim 1 or 2, wherein the leakage current detecting means has an averaging processing function for averaging the leakage current active component for a predetermined time. The insulation monitoring system according to claim 1 or 2, wherein the monitoring control means includes a graphing function for graphing the leakage current active component. The insulation detection system according to claim 1 or 2, wherein the monitoring control means has a graphing function for graphing the leakage current active component and the leakage current reactive component. The insulation monitoring system according to any one of claims 5 to 7, wherein the measurement voltage superimposing means and the leakage current detecting means are controlled by supervisory control means. The function according to any one of claims 5 to 7, wherein the monitoring control means stores the leakage current value for each fixed period, constantly monitors the change of the leakage current value, and issues an alarm when the preset limit value is exceeded. Insulation monitoring system comprising a. 8. The insulation monitoring system according to any one of claims 5 to 7, wherein the leakage current detecting means has an averaging processing function for averaging the leakage current active component for a predetermined time period. 8. The insulation detection system according to any one of claims 5 to 7, wherein the detection control means includes a graphing function for graphing the leakage current active component. 8. The insulation monitoring system according to any one of claims 5 to 7, wherein the sensing control means has a graphing function for graphing the leakage current active component and the leakage current reactive component. ※ Note: The disclosure is based on the initial application.