Application of Unloading Branch to Improve Wind Power System’s Low Voltage Ride Through Capability
Meng Qingtian1, Yan Zhihai2
1.Inner Mongolia Electric Power Science Research Institute, Huhhot 010020; 2.Erdos Electric Power Company, Erdos, Inner Mongolia 017010; 3.Inne Monglia Electric Power Surrey and Design Institute, Huhhot 010020
Abstract：In response to direct driven wind power system with full scale back to back converter and permanent magnet synchronous generator(PMSG),unloading branch measure is proposed to improve the wind turbines low voltage ride through (LVRT) capability. This paper analyzed PMSG system transient behavior. Focused on the transient behavior of the grid voltage drop when power system fault. The PMSG wind power connecting grid system was simulated in PSCAD/EMTDC. A detailed description of PMSG and its controller options were presented. The simulation results showed that unloading branch deals with the unbalance power quickly when the network voltage dips,and the DC-bus voltage keeps constant. Then the wind turbines are isolated from grid fault. The wind power system can remain connected to the grid and the system’s low voltage ride through capability is enhanced.
2013, Vol. 14 
