Power Perturbation Method for the Voltage Ride Through Operation and Islanding Detection of Grid-Tied Renewable Energy Generation Systems

With the scale of grid-tied renewable energy generation systems increasing significantly, the grid stability and safety have to be ensured by new strict grid code. The low voltage ride through (LVRT) regulation which requires the renewable energy generation systems should connect and provide reactive power to support during grid fault and the islanding detection which ensures grid safety are two focuses in the grid code of many countries. This paper proposes a power perturbation method, which consists of dual second order generalized integrator (DSOGI) PLL, power perturbation module and islanding detection module. This method can meet the requirement of LVRT and islanding detection simultaneously by adjusting proportion of active power current and reactive power current generated by grid-tied renewable energy generation systems. Finally, validity and accuracy of the proposed method was verified by simulation results.