A nonstandard control strategy for active power filters for unbalanced conditions of the power mains

This paper investigates the utilization of a control strategy for active power system employed under unbalanced conditions of the power mains. The proposed scheme reduces the problems verified in the conventional strategies when the power mains is unbalanced. The system model under unbalanced condition is derived and a suitable control strategy is presented. This strategy is composed of a parallel association of double sequence current controller and a resonant current controller. With this control scheme a full compensation of the current load harmonics is achieved. The feasibility of the control system is validated by experimental results.