Design and experimentation of interleaved PWM and generalized control schemes for paralleled grid converters of wind energy systems

The purpose of this paper is to design and implement the interleaved PWM and generalized control schemes for the paralleled grid converters. The key is to design the shifted angle among the PWM carriers of different grid converters, in such a way that the switching harmonics in the total grid current can be mitigated. By detecting and controlling the negative-sequence components in grid voltages and currents, the generalized grid synchronization and current controllers are designed to operate effectively under various grid voltage conditions, and thus ride through the short periods of grid faults. The laboratory prototype is setup, and the experimentation is given to verify the validity of the proposed interleaved PWM and the generalized control schemes.