双馈风电机组低电压穿越参考功率优化整定

Optimal Setting of Reference Power for Low Voltage Ride-Though of Wind Turbines With Doubly Fed Induction Generators

在综合双馈风电机组已有低电压穿越方法的基础上,提出一种双馈风电机组低电压穿越参考功率优化整定方法。在详细分析电压跌落引发crowbar保护动作后的双馈风电机组机电暂态过程的基础上,根据转子运动方程,推导了电压跌落持续期间双馈感应发电机不发生超速脱网的条件,给出了双馈感应发电机参考功率的整定计算公式。基于PSCAD/EMTDC V4.2.0仿真软件,搭建了某型号1.5 MW双馈风电机组的低电压穿越仿真模型。仿真结果表明,在电压跌落持续期间,所提出的参考功率整定方法既能减轻双馈感应发电机转速增加程度,又能使双馈感应发电机向电网发出一定无功功率,进而验证了所提方法的有效性。

On basis of existing low voltage ride-through （LVRT） method of wind turbines with doubly fed induction generator （DFIG）, an optimal setting of reference power for LVRT of wind turbines with DFIG is proposed. Based on detailed analysis of electromechanical transient process of DFIG after action of crowbar protection triggered by voltage dip in grid, according to rotor motion equation, criterion for checking overspeed is deduced and setting formulas for reference power of DFIG is presented. Simulation example of a 1.5 MW wind turbine with DFIG is constructed in PSCAD/EMTDC V4.2.0. Simulation results show that increasing degree of rotor speed is reduced and DFIG offers certain amount of reactive power to grid during voltage dip based on the proposed method for optimal setting of reference power, therefore verifying effectiveness of the proposed method.