Research On Coordination Control Of Reactive Power And Voltage For Wind Farms

With the increase of wind power, the voltage problem that wind power brings on power system becomes more serious than before. The reactive power and voltage control is a very important problem that needs to solve well. In China, adjacent wind farms in a region are usually integrated to power grid as a whole. These wind farms in a region respond similarly to disturbance. In order to improve the voltage quality and reduce power loss, a coordinated control strategy for the management of wind farms and collecting substation is proposed in the paper.At first, the reactive power regulation capability of wind turbine and reactive power compensation devices in wind farm is analyzed. SCIG wind turbine, DFIG wind turbine and PMSG wind turbine are studied respectively. The reactive power characteristic of different compensation device in wind farm is also studied.Secondly, the paper designs a coordinated voltage control system of the wind farms. The framework, communication information, modular function of system is described in detail. Taking the coordination of wind farms and collecting substation into account, a coordinated voltage control strategy of wind power region is proposed in this paper, including the voltage control strategy of collecting substation and the voltage control strategy of wind farms.Finally, the proposed strategies are tested in a real power grid integrated with wind farms. The simulation result shows voltage quality is improved and power loss of the region decrease obviously. The simulation also demonstrates the effectiveness and validity of the proposed strategy.