A new hybrid active power filter (APF) topology

In this paper, a new hybrid active power filter topology is presented. A higher-voltage, low-switching frequency IGBT inverter and a lower-voltage high-switching frequency MOSFET inverter are used in combination to achieve harmonic current compensation. The function of the IGBT inverter is to support utility fundamental voltage and to compensate for the fundamental reactive power. The MOSFET inverter fulfils the function of harmonic current compensation. To further reduce cost and to simplify control, the IGBT and MOSFET inverters share the same DC-link via a split capacitor bank. With this approach, harmonics can be cancelled over a wide frequency range. Compared to the conventional APF topology, the proposed approach employs lower DC-link voltage and generates less noise. Simulation and experimental results show that the proposed active power filter topology is capable of compensating for the load harmonics