Low Voltage Ride Through Method for Wind Turbines Based on Cooperative Control Strategy of Multiple Reactive Power Sources

With the consumption of traditional energy, renewable energy has gradually become the main force of energy production. To avoid the wind turbines tripping-off caused by the fault of power grid, the renewable energy transmission system usually needs to be equipped with a variety of reactive power compensation devices. To improve the reliability of LVRT (low voltage ride through) of wind turbines under the failure of the sending-end system, a LVRT method for wind turbines based on the cooperative control strategy of multiple reactive power sources is proposed in this paper. Firstly, this paper analyzes the reactive power output capability of the DFIG (doubly fed induction generator) and PMSG (permanent magnetic synchronous generator); and the reactive power output capability of typical reactive compensation devices i.e., SVG (static var generator) and synchronous condenser, is introduced. Secondly, based on the remaining reactive power compensation capacity and response speed of each reactive power source, the voltage regulation participation index defined as VRPI is introduced. Consequently, the cooperative control strategy of multiple reactive power sources is proposed based on the introduced index. Finally, case study of typical fault of the sending-end system integrated with wind turbines is performed, the simulation results show the effectiveness of the proposed cooperative control strategy of multiple reactive power sources.