Transformer-less five-level diode-clamped converter based active power filter.

摘要

Power quality is an ever-growing concern. A major contributor to power pollution are the harmonics created by various system loads. This thesis proposes a new approach to filter the harmful harmonics using a shunt active filter using a five-level diode-clamped converter. A multi-level converter provides superior filtering performance however, it suffers from a voltage imbalance in its DC-link. Therefore, a novel control method for an auxiliary balancing circuit and a new pulse-width modulator are also proposed. The mathematical model of the proposed filter is derived through its state-space equations. This model is then used to design two controllers. To validate the proposed filter a model was constructed and simulated in Matlab/SimPowerSystems RTM. Results show that the proposed filter can effectively reduces harmonics while keeping its DC-link balanced.Keywords: Multilevel DCC, Active Power Filter, Pulse-Width Modulator (PWM).