INSULATION MONITORING DEVICE AND INSULATION MONITORING SYSTEM

摘要

To provide an insulation monitoring device and an insulation monitoring system for improving monitoring accuracy by reliably extracting a resistance component current of a predetermined frequency even in a case with contact of monitoring signals.SOLUTION: An insulation monitoring device includes: injection units 10A and 10B for injecting a monitoring signal of a predetermined frequency different from a system frequency to ground lines 30A and 30B of transformers 1A and 1B connected to a power system; and measurement units 20A and 20B for detecting a resistance component current of the same phase as that of a monitoring signal voltage by measuring a leakage current of a predetermined frequency reflowing from the ground lines 30A and 30B via ground insulation resistances, so as to monitor an insulation state. The injection units 10A and 10B respectively generate a monitoring signal by allowing a reference signal component having a reference frequency to be superimposed on a neighboring signal component having a neighboring frequency thereof. The measurement units 20A and 20B respectively detect a resistance component current from a leakage current of the neighboring signal component.SELECTED DRAWING: Figure 1