A Novel Hybrid Switching Scheme based Implementation of Shunt Active Power Filter

Shunt Active Power Filters (SAPF) are universally used to curtail current harmonics appearing in the utility grids due to abundance of non-linear loads. This paper elucidates a detailed design and operation of a two level SAPF. Various control schemes are described and a novel, but easily implementable control scheme is proposed so as to enhance the overall performance of SAPF. The proposed controller is self-adaptive in nature and does not require complex computations pertaining to current error limitation, as a standard Space Vector Pulse Width Modulation (SVPWM) technique is used. The proposed current controller overcomes inherent limitations of random voltage vector switching encountered in conventional hysteresis current controller based SAPFs and inconsistent switching leading to spurious spikes appearing in a modified approach of hysteresis current control. The compensation in terms of considerable curtailment of current harmonics is provided by the proposed controller, thus ensuring the best possible results. Detailed theoretical analyses and simulation studies are presented in the paper and the claimed performance of the proposed controller is evident from results. Additionally, the proposed controller ensures the scalability for any multi-level converter topology used for SAPFs. To verify the effectiveness of the proposed control, the SAPF system is simulated in MATLAB Simulink environment, and the results portray favorable outcomes with 1.28% lower source current THD and better EMI performance.