Study on coordinated voltage control strategy of DFIG wind farm

This paper studies a combined voltage control strategy that coordinates a variety of reactive compensative devices such as fixed capacitors, SVC/Statcom, DFIGs (Double-fed Induction Generators) to improve voltage control performance in multi-time scale. Based on the control restraints and response performance, three modes - planning mode, online mode and emergency mode - are optimized for lower cost and higher security margin, respectively. The paper introduces wind power forecast into wind farm voltage planning for slow, discrete devices such as fixed capacitor, while engages devices that are capable of instantaneous response to smooth quick, small voltage fluctuation and track online voltage reference from dispatching centre. The feasibility, effectiveness and superiority of the proposed control strategy are verified with simulation.