Experimental Investigations on Single-Phase Shunt APF to Mitigate Current Harmonics and Switching Frequency Problems Under Distorted Supply Voltage

This paper presents an experimental validation of, phase-lock loop less modified control strategy for single-phase shunt active power filter (APF) to compensate current harmonics and reactive power in single-phase distribution system under distorted supply voltage. The control technique is divided into two parts: first associated with selected frequency signal extraction by using Hilbert transform-based adaptive tuned filter from distorted supply voltage followed by reference current signal generation using DC-link energy balance method. Second deals with an improved pulse width modulation technique which reduces switching ripple and switching frequency for voltage source inverter used as a shunt APF. The overall control scheme is simulated using MATLAB/Simulink environment in the steady state and transient condition of the load. A detailed hardware design and other parameters of proposed system have been presented. A laboratory prototype has been developed using dSPACE DS1104 controller card having TMS320F240 as a slave DSP to verify the simulation results. Simulated and experimental results show that the proposed control technique gives a flexible and fast dynamic response in single-phase distribution system. The harmonic spectral performance of the proposed technique is as per the recommendation of IEEE-519 standards.