ANTI-ISLANDING DEVICE AND METHOD OF PHOTOVOLTAIC GENERATION SYSTEM USING SMALL REACTIVE POWER VARIATION

摘要

An anti-islanding device of a photovoltaic generation system using a small reactive power variation comprises a frequency change detecting unit which detects a change in the frequency of an output voltage outputted from a photovoltaic inverter; a reactive power variation detecting unit which detects a variation of reactive power in output power outputted from the photovoltaic inverter; a correlation result calculating unit which calculates a correlation result value between a frequency change and a reactive power variation using the correlation between the change in the frequency of the output voltage and the variation of the reactive power; a correlation result comparing unit which compares the correlation result value calculated by the correlation result calculating unit and a threshold and outputs an islanding state signal if the correlation result value is greater than or equal to the threshold; an inverter operation controlling unit which determines that the operation state of the photovoltaic generation system is an islanding state if receiving the islanding state signal outputted by the correlation result comparing unit and then outputs an operation control signal to control the operation of the photovoltaic inverter; and an inverter operation stopping unit which stops the operation of the photovoltaic inverter by receiving the operation control signal outputted by the inverter operation controlling unit.;COPYRIGHT KIPO 2015