Optimal unified power quality conditioner with improved compensation performance under distorted voltages

In this paper, practical applications of optimal and flexible controlled (OFC) active filters operating under distorted voltages with non-ideal compensator systems are investigated. In the previous works, the compensator system is regarded as an ideal inverter. On the contrary, this paper takes into account a set of important limitations of the real compensators in frequency domain. Some restrictions are caused by the inverter´s bandwidth limitation. To overcome the tracking error, several approaches are suggested. In a very effective approach, each single-phase inverter is treated as a multivariable system in frequency domain to be compensated by means of a simple identification/ equalizer system quite suitable for the OFC system under study. It is shown that using a series compensator besides removing the load voltage harmonics, can significantly improve the tracking performance of the shunt compensator. Extensive simulation results obtained in Matlab/Simlulink environment prove the feasibility and superiority of the proposed approaches.