Harmonic series compensators in power systems: their control via sliding mode

This paper deals with harmonic current compensation in power systems using shunt passive and series active filters. It is shown how constraints of the active filters can notoriously degrade the performance of the compensating system. The use of variable structure system theory is suggested for analysis and design of series active filters. Sliding mode control strategies to improve harmonic rejection are proposed, and active filters with different switching-ripple filters are considered. These control strategies provide robustness to active filter modeling errors and external disturbances.