基于桨距角控制的双馈风机参与电网二次调频控制策略研究

Research on control strategy of DFIG participating in secondary frequency regulation based on pitch control

单独依靠常规电源的热备用难以有效平抑大规模风电的功率波动,要求风电机组主动参与自动发电控制(AGC)是电力系统稳定运行的重要保证。为解决此问题,本文提出了一种基于桨距角控制的双馈风机(DFIG)参与电网二次调频控制策略。通过分析风机的特性,确定了考虑桨距角变化的最优转速功率追踪控制;通过引入风电场控制信号改进传统桨距角机构,并在此基础上进一步提出了双馈风机参与电网二次调频综合控制方案。仿真结果表明,在所提控制方案下,风机利用其可控的二次调频能力,有效地降低了严重的负荷扰动下系统频率的变化率,并实现了间歇式新能源的优先调度。

It is difficult to suppress effectively the power fluctuation of large-scale wind power generation only by the spinning reserve of traditional power sources. Hence,active participation of wind power plants in automatic generation control( AGC) is of significance to ensure the stable and safe operation of power system. To resolve this problem,a novel control strategy of doubly-fed induction generator( DFIG) participating in secondary frequency regulation is presented in this paper. Firstly,the optimal speed power tracking control considering pitch variation is determined by analyzing the characteristics of wind turbine. Besides,an improved pitch controller is obtained by introducing the control signal of controller of the wind power plant. Further,an integrated control scheme of DFIG participating in Secondary Frequency Regulation is proposed. The simulation results indicate that DFIG using the proposed control strategy not only inhibits effectively the frequency fluctuation,but achieves the priority scheduling for renewable energy during severe load disturbances.