Nineteen-level Active Filter System using Asymmetrical Cascaded Converter with DC Voltages Control

This paper presents a shunt active power filter implementation based on asymmetrical cascaded multilevel converter. A drawback of using such converter in active filter applications is that it requires DC sources with two quadrants operation capability or system coupling through special transformers in order to avoid voltage-balancing problems. For the proposed control scheme no transformer is used and the DC voltages are individually controlled. Hence, no DC source is required to maintain the capacitors voltages constant. A start-up procedure is also discussed. Simulation and experimental results are provided to validate the proposed scheme