Shunt active filter based on multirate sampled timer comparison technology

Traditional timer comparison control method for shunt active power filter induces a low switching frequency and a large current ripple. To address these problems, this paper proposes a novel multirate sampling timer comparison control strategy, which can improve the system's control performance. Output current of active power filter is sampled much faster than load current, and this method can implement multiple effective controls in every frame period, while reactive power and harmonic current reference values are calculated just once. The characteristics of system with the proposed controller are investigated and compared with the traditional strategy. Simulation and experiment results of double sampling rate control demonstrate the effectiveness of the proposed method.