A Passivity-Based Control for Power Electronics Converter in a DFIG Wind Turbine

Utilization of the power electronics converter in a doubly-fed induction generator wind turbine, thus decoupling mechanical and electrical frequencies and making variable-speed operation possible, can vary the electrical rotor frequency. This paper addresses the circumstances of no matter either capacitor voltage or inductor current is chosen as the output in a converter, the zero dynamics is not both stable for two power flow direction cases. A passivity-based controller for back-to-back converter is presented to avoid this problem in wind power generation. Based on the port-controlled hamiltonian model of the converter, the structure matrix and the damping matrix are collocated and the desired equilibrium is approached rapidly. Simulation studies are carried out in Matlab/Simulink and the results show that the new control method enables to avoid instability for a bidirectional use of the power converter in DFIG wind turbine.