A coordinated reactive power and voltage control system for wind farm grid integration

Rapid increase of wind power installation in China brings new technical issues and challenges for grid security operation. Reactive power and voltage control capability of wind farms is one of key issues that grid operators concern with. This paper presents a coordinated reactive power and voltage control system for wind farm gird integration to meet operation requirements described in the standard of State Grid Corporation of China “Technical rule for connecting wind farm to power system”. The control strategy of the proposed system takes into account the coordination between voltage and power factor. The proposed system includes two control modes, i.e., schedule voltage tracing mode and optimization mode. To prove the effectiveness of the proposed strategy, a simulation study is first implemented. Based on this, a control system with the proposed control strategy is developed. Then a field test is carried out in Shanghai Fengxian Haiwan Wind Farm to verify the characteristics of reactive power output and voltage tracking of the system. The results demonstrate that technique indices of reactive power and voltage control system (RPVCS) can satisfy the requirements of the standard. It can improve the voltage stability by effective control of reactive power of wind farm.