Shunt hybrid active power filter for harmonic mitigation: A practical design approach

The increasing importance of Power Quality problems has been responsible for several improvements in Active Power Filter (APF) typologies in the last decade. The increased cost and switching losses make a pure shunt APF economically impractical for high power applications. In higher power levels shunt Hybrid Active Power Filter (HAPF) has been reported to be a useful approach to eliminate current harmonics caused by nonlinear loads. This paper presents a control strategy and design criteria for transformer-less shunt HAPF with special attention to the integration of series passive filter. The paper also compares the performance improvement of passive harmonic filter when modified as shunt HAPF. Experimental results obtained verify the viability and effectiveness of the proposed design criteria and control algorithm.