Calibration Method of DC Leakage Current Sensor for DC System Insulation Monitoring

Abstract

The invention relates to a calibration method for a DC leakage current sensor for DC system insulation monitoring, which belongs to the technical field of DC system insulation monitoring; it is applied to a DC system insulation monitoring DC leakage current sensor system, and the DC system insulation monitoring DC leakage current sensor system It includes a DC system insulation monitoring device, a DC leakage current sensor data acquisition device, and an open-type DC leakage current sensor; the calibration method of the DC system insulation monitoring DC leakage current sensor includes judging the insulation condition of the DC system, and the positive and negative poles of the DC system. Value acquisition and leakage current value acquisition, calculation of leakage current calibration value; automatic calibration of "zero drift" problem without adding additional bridge combination, suitable for DC system insulation monitoring using "unbalanced bridge method + DC leakage current method" device.

Description

technical field [0001] The invention relates to a calibration method for a DC leakage current sensor for DC system insulation monitoring, and belongs to the technical field of DC system insulation monitoring. Background technique [0002] At present, the insulation monitoring device of the substation DC system basically uses the DC leakage current method to locate the insulation fault of the branch and calculate the resistance of the branch. Using the DC leakage current method must use a DC leakage current sensor for DC leakage current acquisition. The DC leakage current sensor can be divided into two types according to its composition, one is a closed type DC leakage current sensor, and the other is an open type DC leakage current sensor. The open-type leakage current sensor has good linearity, but because it is susceptible to environmental influences such as the geomagnetic field, it causes the problem of "zero drift", that is, the sensor output zero point deviates from t...

AI Technical Summary

Problems solved by technology

The open-type leakage current sensor has good linearity, but because it is susceptible to environmental influences such as the geomagnetic field, it causes the problem of "zero drift", that is, the sensor output zero point deviates from the actual value, so the open-type DC leakage current sensor is used for insulation fault branch location and resistance. The calculated insulation monitoring device often has the problem of misselecting the branch and inaccurate calculation of the grounding resistance of the fault branch

In the past, DC leakage current sensors were often manually zeroed and calibrated through their physical knobs, which was time-consuming and laborious

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