直驱风电系统自适应惯量和一次调频协调控制策略

Adaptive Inertia and Primary Frequency Modulation Coordinated Control Strategy of PMSG System

提出一种直驱风电系统自适应惯量和一次调频协调控制方法:构建了基于运行曲线偏移的频率支撑统一控制框架。该框架首先根据电网对风电场的调频需求以及直驱风机控制结构,确定风电机组的运行曲线簇;进一步通过引入运行曲线偏移机制并结合df/dt前馈环节,实现对电网的频率支撑。该方法可将直驱风电系统的惯量支撑以及一次调频支撑集成在一起,风电场自适应选择合理的风力机功率跟踪曲线,实现电网调频需求,尽可能减少因调频控制导致的风能利用效率的降低,同时还可削弱惯量响应过程中原控制系统外环对df/dt前馈控制环的抵消作用。最后基于PSCAD/EMTDC电磁暂态仿真验证了分析结果和所提方法的有效性。

This paper proposes a coordinated control method of adaptive inertia and primary frequency modulation for PMSG system and constructs a unified control framework of frequency support based on curve shifting. First,the framework determines the operation curve cluster of the wind turbine according to the frequency modulation demand of the grid and the control structure of PMSG;and then the framework introduces the mechanism of operation curve deviation and the df/dt feedforward loop,to support the system frequency. This method can integrate the inertia support and the primary frequency modulation support of the PMSG together. Thus,the wind farm can adaptively select the power tracking curve of the WT to achieve the frequency modulation demand of the power grid,and reduce the waste of wind energy caused by the frequency modulation control as much as possible. At the same time,it can weaken the counteraction of the outer loop of the original control system to the df/dt feed-forward control loop in the process of inertia response. Finally,based on PSCAD/EMTDC electromagnetic transient simulation,the effectiveness of the proposed method is verified.