57　A proposal of the improvement an insulation resistance measurement of photovoltaic module strings by the self-bias method considering circuit behavior

Abstract

Regarding the self-bias method which is well known as measuring the insulation resistance of photovoltaic module strings, that measurement circuit may make the voltage against the earth rise to the generating voltage. We considered them using the equivalent circuit model between a photovoltaic module string and the earth from safety in case of constant monitoring the insulation resistance, and experimented. In this paper, we propose an improvement of the measurement method for the development of the insulation monitoring device.