Control strategy of doubly-fed wind turbine generator-MW level

This paper specializes the control strategy study for variable speed constant frequency (VSCF) doubly-fed wind turbine generator-MW level, particularly creates their mathematical models of excitation control system of doubly-fed asynchronous motor, rotor-side frequency converter, line-side frequency converter, pitch controller and torque controller, and builds its control workflow of doubly-fed wind turbine main control system and its performance curve. The result of system operations proves that doubly-fed wind turbine generator-MW level owns the good ability of bid-directional power flow, and the lower input & output harmonic content to meet the requirement of variant speed constant frequency wind turbine and be good to grid-connected operation with the large power grid system.