Research on High Voltage Ride Through of Wind Turbine based on Combination of Series Impedance Divider and Parallel High Impedance Grounding

Abstract

The impact of high voltage ride through (HVRT) capability of wind energy on the security of power grid is therefore much concerned. At present, there have been no explicit requirements for technical rules of HVRT. However, the high voltage phenomena may occur during the voltage recovery after the clearance of short circuit faults, and the operation of power grid could also lead to high voltages. With the increasing scale of integration of renewable energy, the high voltage issue has become an important barrier that limits the large-scale integration of wind power. Therefore, it is very necessary to carry out research on HVRT to make sure the security and stability of power grid with large-scale wind power. This paper proposes an HVRT method for wind turbine based on combination of series impedance divider and parallel high impedance grounding equipped at the wind turbine terminal. According to the voltage dividing characteristic of impedance in the classic circuit analysis, the series impedance is installed at the wind turbine terminal. During high voltage period time, switch series impedance is closed to realize high-impedance grounding that decreases the terminal voltage. When the voltage recovers to normal range, cut off series impedance, then HVRT is fulfilled.