An active power filter with direct current control for power quality conditioning

Fast dynamic response and high-frequency switching make the active power filter an appropriate converter to implement the correction of low-power quality events and impose a sinusoidal current in the grid at the point of common connection. In this article, a new simple and robust control structure for an active power filter is designed, simulated, and tested. The current loop, based on the DC bus energy balance, is intuitive, robust, simple to implement, and allows a fast dynamic response. The implementation is validated with simulated and experimental results obtained in a three-phase 5-kVA prototype.