GROUND FAULT DETECTION DEVICE, GROUND FAULT DETECTION METHOD, SOLAR ENERGY SYSTEM, AND GROUND FAULT DETECTION PROGRAM

摘要

In a ground fault detection device, two photovoltaic strings are disconnected from a photovoltaic power generation system, measurement for one photovoltaic string is performed by a measuring instrument, and in parallel therewith, the other photovoltaic string before measurement is charged/discharged by a charging/discharging unit by executing various functions of the calculation control unit. In other words, charging/discharging of the photovoltaic string is performed in advance at the same timing as the measurement of the photovoltaic string so that the measurement can be performed immediately after the photovoltaic string is connected to the measuring instrument in a subsequent step.

主权项

1. A ground fault detection device which detects a ground fault within a photovoltaic array in a photovoltaic power generation system comprising:
photovoltaic strings configured in such a manner that a plurality of photovoltaic modules are connected in series; the photovoltaic array configured in such a manner that the plurality of photovoltaic strings are connected in parallel; and a load device which consumes or converts power, wherein the ground fault detection device includes a switching unit which disconnects two or more photovoltaic strings among the plurality of photovoltaic strings from the photovoltaic power generation system by electrically separating the photovoltaic strings from each other; a measurement unit which connects to each of the plurality of photovoltaic strings to perform a predetermined measurement; a charging/discharging unit which connects to each of the plurality of photovoltaic strings and charges/discharges the photovoltaic string so that its potential relative to the ground is the same as the potential relative to the ground when the photovoltaic string is connected to the measurement unit; and a control unit which performs at least control of operation of the measurement unit and the charging/discharging unit, and the ground fault detection based on a measurement value of the measurement unit, and the control unit causes the measurement unit to perform the predetermined measurement on one photovoltaic string among the two or more photovoltaic strings disconnected by the switching unit, as a measurement target string, and in parallel therewith, causes the charging/discharging unit to charge/discharge the other photovoltaic strings which are separate from the measurement target string and have not yet been subjected to the predetermined measurement among the two or more photovoltaic strings disconnected by the switching unit, as charging/discharging target strings.