Modeling and control on grid-connected inverter stage of two-stage matrix converter for direct-drive wind power system

摘要

Applying two-stage matrix converter (TSMC) to direct-drive wind power has advantages compared to traditional AC-DC-AC converters. The valid control on grid-connected inverter stage of TSMC is the key to achieve independent control on active and reactive power of generation system. However, mathematic model of inverter stage of TSMC in synchronous coordinates is a double-input and double-output coupling structure. This coupling structure is difficult to achieve accurately decoupling control on active and reactive current. By using complex vector modeling, the model of grid-connected inverter stage of TSMC is transformed into single-input and single-output vector structure. And a feed-forward complex PI compensator is figured out to achieve completely decoupling control on active and reactive current. Finally, comparative study is to ensure the validity and feasibility of the proposal control strategy by comparing to conventional PI control.