Design on four-quadrant DC/AC converter for wind power flow optimization system

A four-quadrant DC/AC converter for wind power flow optimization system is designed. Firstly, the basic idea of wind power flow optimization and control is analyzed. Secondly, working principle of the four-quadrant DC/AC converter is explained and its linear small signal mathematical model in the rotating reference frame is constructed. Then, based on the model, control unit consisting of active current PI close-loop regulation and reactive current one is designed. The high frequency component of the output power of wind power generation is separated by a one-order low pass filter, which is used to produce the active power command of the converter. In addition, the reactive power command is produced based on the deviation between the gird voltage in real time and the ideal one. The experimental results show that the converter can rapidly and accurately trace active power command and reactive power one of different direction and size.