双馈式风电场改进的恒电压控制策略  

Improved constant voltage control strategy of DFIG based wind farm

作　　者：栗然[1] 唐凡[1] 刘英培[1] 柯拥勤[1] 

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),河北保定071003

出　　处：《电力系统保护与控制》2012年第6期79-85,共7页Power System Protection and Control

摘　　要：双馈式风电场采用恒电压控制能够为电网提供电压支持,但风速的随机波动使输电线路潮流频繁变化,给控制系统的稳定性带来了挑战,因此本文对恒电压控制进行改进:通过引入等值风速作为前馈控制,对风速扰动进行补偿,抑制电压波动。为减小双馈风电机组内部有功损耗,提出双层无功分配策略:第一层根据各机组无功极限的大小进行分配,第二层以最大限度的减小机组内部有功损耗为目标,在双馈机定子侧和网侧变流器(GSC)之间进行优化分配。通过仿真,验证了该方法能有效抑制由于风速变化导致的电压波动,并且大大减小双馈风电机组内部功率损耗。DFIG based wind farm can support voltage stability of grid by adopting the constant voltage control operation mode. While power flow of transmission lines changes frequently as a result of wind speed random fluctuations, which brings a challenge to the stability of control system. This paper improves constant voltage control by introducing equivalent wind speed as feedforward to compensate for wind disturbances and inhibition of voltage fluctuations. In order to reduce the internal power loss of DFIG-drived with turbines, double-layer reactive power distribution strategy is proposed. The first layer distributes according to the reactive power limits and the second layer allocates reactive optimally between stator side of DFIG and grid-side converter （GSC） to minimize the unit internal power loss. The method is simulated by Matlab/Simulink. The results reveal that the method can inhibit voltage fluctuation caused by wind speed effectively, and reduce the internal power loss of DFIG greatly.

关 键 词：双馈式风电场 恒电压控制 前馈控制 双层无功分配 功率损耗 

分 类 号：TM315[电气工程—电机]