A control strategy of three-phase active power filter with unity power factor

The control strategy of three-phase active power filter is discussed base on one-cycle control technology. No matter how the source voltages are balanced or unbalanced, the control strategy of active power filter can be determined by calculating the unbalanced parameters of the source voltages and determining the duty ratios of switches in phase. With this control strategy, the active power filter can make the source currents in-phase with the source voltages which can results in unity power factor of the system. Finally the simulation of the control strategy is made, and the results of simulation show that active power filter with this control strategy can effectually compensate the harmonics and make the losses of switches reduced. Because it does not need harmonics checking circuit, the control circuit is simple and has capacity of fast following.