含STATCOM的双馈电机风电场无功电压协调控制策略

Research on coordination control strategy of DFIG wind farm with Crowbar circuit

为增强风电场并网点电压稳定性,提出了变速恒频双馈风电场与动态无功补偿装置STATCOM间的无功电压协调控制策略。电网故障导致风电并网点不同深度的电压跌落时,根据双馈风机Crowbar保护投切状态,对DFIG风电机组转子侧及网侧变流器与STATCOM进行无功功率分配,协调控制促进风电场LVRT期间风电并网点电压的快速恢复。最后,在DIg SILENT/Power Factory仿真软件中建立了风电场和STATCOM控制模型,通过仿真验证该控制策略的有效性。

To enhance the stability of the grid voltage with grid-connected wind farm,this paper analyzes the voltage and reactive power control of wind farms,and a coordinated control strategy based on doubly fed wind turbine（ DFIG） and reactive power compensation equipment STATCOM is proposed. When the grid fault leads to different degrees of voltage sag,reactive power between DFIG and STATCOM can be allocated according to the Crowbar protection status. By this way,DFIG grid-side converter and the stator side reactive power generation ability are fully utilized,providing more dynamic reactive power to the grid for voltage support during the system＇s fault. Thus the voltage at the point of common coupling（ PCC） during the LVRT period of wind farm is controlled and transient voltage recovery process is sped up. Finally,the proposed coordinated control strategy is simulated with a DFIG wind farm with STATCOM in DIg SILENT / Power Factory,and the simulation results verify the effectiveness of the proposed scheme.