INSULATION MEASURING DEVICE FOR PHOTOVOLTAIC POWER GENERATION APPARATUS AND METHOD FOR MEASURING INSULATION OF PHOTOVOLTAIC POWER GENERATION APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide an insulation measuring device for a photovoltaic power generation apparatus capable of performing insulation measurement by measuring a power generation voltage and a voltage between measurement device resistances in a power generating state without performing processing before measurement such as an insulation resistance tester, and to provide a method for measuring insulation.SOLUTION: The insulation measuring device for a photovoltaic power generation apparatus measures a voltage (a power generation voltage) V between a P phase and an N phase on a power supply side, with a wiring breaker 4 in a relay terminal box 2 or in a power conditioner opened and a ground voltage Vpr of a P-phase terminal 4p via a measuring device resistance R, and a voltage (a power generation voltage) V between the P phase and the N phase on the power supply side, with the wiring breaker 4 opened and a voltage Vnr of the N-phase terminal 4n via the measuring device resistance. A decrease in P-phase insulation resistance Rgp in a DC circuit extending from a solar panel 1 to the wiring breaker 4 and a decrease in N-phase insulation resistance Rgn in the DC circuit are detected in a discrimination manner by a calculation based on the measured result.