基于转子动能的直驱式风电系统RoCoF下垂控制策略  

RoCoF Droop Control Strategy for Direct-drive Wind Power System Based on Rotor Kinetic Energy

作　　者：查雨欣 林健[1] 张树龙 张仪 ZHA Yuxin;LIN Jian;ZHANG Shulong;ZHANG Yi(School of Automation,Nanjing Institute of Technology,Nanjing 211167,China)

机构地区：[1]南京工程学院自动化学院,江苏南京211167

出　　处：《智慧电力》2022年第4期21-26,34,共7页Smart Power

基　　金：国家自然科学基金资助项目(61873120);江苏省研究生科研与实践创新计划项目(SJCX20_0713)。

摘　　要：大规模风电并网会引起系统的等效惯量阻尼下降,降低系统频率的稳定性。微电网系统以电力电子设备为主导,在受到外界扰动时,更易出现电网频率偏差和频率变化率(RoCoF)过大的问题。在分析直驱永磁同步发电机(D-PMSG)并网系统动态响应基础上,将其与低惯量微电网相连接,提出了一种基于有源低通滤波器(LPF)的RoCoF下垂控制策略,该策略在风机侧引入电网的RoCoF,在频率跌落RoCoF突变的瞬间释放转子能量,补偿系统不平衡功率。在Matlab/Simulink中建立仿真模型,验证控制策略的有效性及经济性。结果表明,增加下垂系数Kd和降低截止频率ωc,可使系统惯量越高,系统对RoCoF的抑制效果越好。Large-scale wind power grid integration will cause the equivalent inertia damping of the system,resulting in a decrease in system frequency stability. Microgrid systems dominated by power electronic equipment are more prone to grid frequency deviation and rate change of frequency(RoCoF)when subjected to large external disturbances. Based on the analysis of the dynamic response of DPMSG grid-connected system,connected with low-inertia microgrid,RoCoF droop control strategy based on the active low-pass filter(LPF)is put forward. This strategy introduces RoCoF to the power grid on the wind turbine side,and releases rotor energy at the moment of sudden change of RoCoF when the frequency drops to compensate the unbalanced power of the system. A simulation model is established in Matlab/Simulink,and the simulation verifies the effectiveness and economy of the control strategy. The simulation results show that increasing the droop coefficient Kd and reducing the cut-off frequency ωc can make the system have higher inertia and better suppression effect of RoCoF.

关 键 词：下垂控制 直驱式永磁同步风力发电机 微网 惯量特性 

分 类 号：TM314[电气工程—电机]