A novel hybrid active filter for power quality improvement and neutral current cancellation

In this paper a new hybrid active filter is proposed that combines harmonic filtering and neutral current compensation. The main difference between proposed topology and conventional structures consists of the connection of neutral wire to positive terminal of DC link capacitor thus avoiding the need of split capacitor or forth leg for neutral current cancellation that reduces the manufacturing cost. A simple control method based on damping resistor is used to achieve desired harmonic compensation and neutral current cancellation. Simulation results show that proposed hybrid active filter has the expected performance.