A Novel Predictive Current Control For Active Power Filter

The zero-order hold, data-sampling and data-processing of digital controller may cause inevitable control delay in active power filter, which not only affects the harmonic compensation performance, but also causes the instability of active power filter. In order to eliminate the delay effect, a novel predictive control combined with reference current prediction based on proportion resonance and system model prediction is proposed. The value of inductor changes nonlinearly when the active power filter outputs harmonic current of different orders, while the parameters of prediction control are designed according to the inductor parameters. To eliminate the influence of nonlinear inductor, the function of the inductor parameter changes by the inductor current is constructed, and the control parameters of predictive control are modified according to the function. This method effectively suppresses model errors caused by nonlinear inductor, and increases the speed and accuracy of current prediction. Simulation and analysis of several current control methods verify the validity and feasibility of this current method.