As a growing number of Permanent Magnet Synchronous Wind Turbine Generations (PMSG-WT) are integrated into the modern power grid, there has been a great concern for system operators who expects PMSG-WT to play an active role in the primary frequency regulation when frequency event occurs. However, PMSG-WTs are still unable to provide any additional active power in response to the system frequency change. In this work, a control scheme of coordinated frequency regulation for DFIG in [1] is redesigned and implemented into a PMSG-WT model by synthesizing the inertial control, over-rotor speed control and pitch angle control. Inertial control emulates the total inertia response of both wind turbine and generator to provide a short-term frequency support. According to the de-loaded optimum power extraction curve, the over-rotor speed and pitch angle controls are coordinated to maintain the reserved power and meanwhile assist the primary frequency regulation in a long-term period. The coordinated control strategy of PMSG-WT comprises the low, medium and high wind speed modes. By this means, the comprehensive control method will promote the PMSG-based wind farms to effectively participate in the system frequency regulation under a full scope of wind speed conditions.
展开▼
