An Improved Islanding Detection Method Based on Correlation Technique Using Reactive Power Variation

作者：Yu Byung Gyu^*

来源：IEEJ Transactions on Electrical and Electronic Engineering, 2014, 9(5): 465-470.

DOI：10.1002/tee.21994

• islanding detection
• reactive power variation
• correlation factor
• grid-connected photovoltaic inverter

This paper presents an improved islanding detection method based on a correlation technique using reactive power variation for a three-phase grid-connected photovoltaic (PV) inverter system. Using a conventional reactive power variation (RPV) method for anti-islanding, the reactive power component of PV inverter output varies periodically within a range of fixed magnitude for the inverter output frequency to go beyond the threshold of the over-frequency relay or under-frequency relay. While the conventional RPV method depends on the frequency relays, the proposed method uses a correlation factor between the commanded reactive power and the corresponding inverter frequency as an islanding detection indicator without relying on the frequency relays. The correlation factor of the proposed method is based on the fact that the commanded reactive power of a PV has a strong correlation with the frequency of the inverter voltage when islanding occurs. The proposed method has fast islanding detection capability and high power quality. In order to verify the proposed islanding detection method, the anti-islanding experimental results of a 250-kW three-phase PV inverter by IEEE Std. 1547.1-2005 are provided.

• 出版日期2014-9