基于STATCOM的风电场SSCI附加阻尼抑制策略

针对双馈型风力发电机经含固定串补的线路接入系统后发生的次同步控制互作用(SSCI)现象，文中提出一种基于静止同步补偿器(STATCOM)的附加阻尼控制器(SDC)，推导了计及SDC时STATCOM的导纳模型，分析了其等效导纳的特点。结果表明，SDC增大了STATCOM在谐振频率处的等效导纳，使得STATCOM能够吸收系统中的振荡能量，增加了系统的阻尼。研究了SDC参数对阻尼特性的影响，包括移相角和比例增益，同时，给出了SDC反馈信号和STATCOM安装位置优化、选择的方案。理论分析和PSCAD/EMTDC仿真验证表明，基于STATCOM的SDC可以有效地抑制次同步控制相互作用，提高系统的稳定裕量。

STATCOM Based Supplementary Damping Mitigation Strategy for Subsynchronous Control Interaction in Wind Farms

To mitigate subsynchronous control interactions(SSCIs)in doubly fed induction generator(DFIG)based wind farm, which is connected to power grid via series compensated transmission line, a static synchronous compensator(STATCOM)based supplementary damping controller(SDC)is proposed. The admittance model of STATCOM with SDC is derived and its equivalent admittance is analyzed. Equivalent admittance reveals that SDC can increase the admittance of STATCOM at the designed frequency. Thus, oscillation energy could be dissipated by STATCOM and the damping of power system is improved. The influence of SDC parameters on the damping of SSCI is analyzed, which includes phase shift angle and proportional gain. Besides, the optimal selection of the input signal of SDC and location of STATCOM are studied to achieve the best mitigation performance. Finally, the proposed scheme is validated by theoretical analysis and simulations with PSCAD/EMTDC. It is proved that the proposed SDC can suppress SSCI effectively and increase the stability margin of the power system.