Operation of a three-level NPC active power filter with unbalanced and nonlinear loads

A scheme to operate the three-level NPC shunt active power filter with unbalanced and nonlinear loads is proposed in this paper. With this scheme, the active power filter can reduce the harmonics, compensate the reactive power and balance real power drawn from the source. Besides the above contents, this paper also tries to reveal the relationship between the voltage ripples on the capacitors and the power consumption conditions in the circuit, which is meaningful for the design of APF. Simulation results have demonstrated this control algorithm.