Formulation of Low Voltage Ride-Through Curve Considering Offshore Wind Farms Integrated into an Islanding Power System - A Case Study in Taiwan

The effects of incorporating large-scale offshore wind farms into the Taiwan Power (Taipower) Company's electricity system must be given attention. The goal of this study was to formulate a new Low-Voltage Ride-Through (LVRT) curve suitable for the Taiwan power grids by analyzing different fault scenarios and times of faults in power grids of the Changbin and Changlin districts after the integration of large-scale offshore wind farms. The proposed LVRT curve can alleviate the effects of circuit trips in the offshore wind turbines on the Taipower system. A power system simulator for engineering (PSS/E) software was employed to analyze the off-peak system of Taipower in 2018 and compare the proposed LVRT curve with the existing Taipower-specified LVRT curve. According to the analysis results, when deployed in the offshore wind turbine system, the proposed LVRT curve not only prevented the decoupling of the turbines and grids during faults, but also reduced the voltage dip at the point of common coupling and the disturbance after the fault clearance. Moreover, according to the transient stability and power generator motor angle analysis, the system could recover stability after fault clearances, thus satisfying the provisions of the Planning Guideline for Power Transmission System and Technical Points for Parallel Connection of Renewable Energy Power Generation System of Taipower Company.