Islanding operation device, islanding detection method, and grid connected inverter system with isolated operation detecting device

摘要

PROBLEM TO BE SOLVED: To provide a reactive power change system of single operation detector, which can properly detect a single operation without increasing the quantity of input reactive power even when a reactive power load is included in a load.;SOLUTION: The single operation detector 6, which detects a single operation state, is provided with a reactive power input unit 61 which periodically inputs a reactive power where a current gains, and a reactive power where a current delays to the output power of an inverter device 2, and a single operation detector 64 which determines whether the phase of an interconnection point voltage signal Vo at an interconnection point (a) has changed. The single operation detector 64 detects the system is in a single operation state when it is determined that the phase of the interconnection point voltage signal Vo has changed. Even when a reactive power load is included in a load B, it can detect a single operation properly because it is determined that the phase of the interconnection point voltage signal Vo has changed in case any reactive power has been input.;COPYRIGHT: (C)2012,JPO&INPIT