Optimization of an Improved Sliding Mode Controller for Shunt Active Power Filter

In this paper, the compensation of load harmonic current is investigated using Lagrange function and minimization of load current active component. The results are compared with load harmonic current compensation using instantaneous three phase reactive power theory. Next the PI and sliding mode controller are modified such that RMS value of error signal is minimized and state variables reach the sliding surface faster than conventional sliding mode controller. This improves the dynamic response of active power filter under load unbalance and harmonics conditions.