Analysis of Different Real Time Reference Generation Techniques used for Harmonic Mitigation in Three Phase Shunt Active filters

This paper presents four types of time domain control techniques for generation of real time compensating current with a view to the problem of source current harmonics caused by non-linear loads in three phase three wire shunt active filters. All the techniques are analyzed mathematically and simulation results are compared in terms of compensation performance with multi parameter under steady state conditions. The four strategies analyzed are the Instantaneous Reactive Power Theory (PQ Theory). Synchronous Reference Frame Theory (SRF), Modified SRF theory without synchronizing circuit like phase lock loop (PLL) and finally all three strategies are compared with the very basic direct compensating current extraction theory. All above methods are completely frequency independent. Simulation results are obtained under sinusoidal balanced voltage source condition. The comparison and effectiveness of all the methods is based on the theoretical analysis and simulation results obtained with MATLAB employing a three phase three wire test system.