Based on the model of voltage-source inverter (VSI) under the synchronized rotating frame

a mathematic model of active power filter has been derived. Furthermore

applying global linearization method for non-linear system

a new nonlinear control method for DC-link voltage of APF has been presented to impel the dc-link voltage of the inverter into steady state in a preset period. Compared with the general used PI-controller

the new one can not only keep away from the trouble to regulate parameters of general controller

but also improve the dynamic and static state compensation performances of APF to keep the controlled system a good rapidity and stability whenever a large or small disturbance injected. Simulation results have verified the feasibility and reliability of the new controller. Although this method is designed for VSI-based APF

the new controller can also be used in other similar occasions where voltage-source converter(VSC) is used.