Control of doubly-fed induction generators for distributed wind power generation

The wind power generation technology has evolved significantly in the past few years with the demand for distributed, renewable energy growing. The doubly-fed induction generator (DFIG) is one of the most attractive solutions among many energy conversion devices for wind energy. The doubly-fed induction generator with a back-to-back four-quadrant ac-dc-ac power converter between the rotor side and the grid side can realize efficient and flexible conversion of wind energy to electrical energy when the wind speed changes. Based on the stator-flux orientation control strategy, this paper discusses control design issues of the DFIG for distributed wind power generation in both gird-connected mode and isolated mode. The PI control method is used in the DFIGpsilas rotor-side power converter to regulate the current, voltage and power. Two cases with grid-connected and isolated modes are studied. Simulation results show that the stator-flux orientation control strategy can achieve good dynamic performances from the distributed wind power generation system in both grid-connected and isolated modes.