LOW VOLTAGE ON-LINE INSULATION MONITORING SYSTEM

摘要

A low voltage on-line insulation monitoring device is provided to display an exact insulation resistance value with a low measurement error or an effective leakage current value correspondent to resistance components. A low voltage on-line insulation monitoring device(18) detects a leakage current flowing to electric line and load zones by low frequency signal voltage and a leakage current flowing to electric line and load zones by low frequency signal voltage by overlapping the low frequencies of two components by a low frequency overlapping device(10) installed at a second ground wire(2) disposed at the low voltage side of a transformer(1), calculates pure resistance components by removing capacitance components irrelevant to an insulation state by computing the two leakage currents, and then displays an insulation resistance value or an effective leakage current value directly related to the insulation state.