Adaptive signal processing based control of active power filters

The paper proposes a simple and practical method for improving the performance of DSP-controlled active power filters (AF). The transfer function of a DSP-controlled AF has a phase-lag property because there is calculation time delay in the control output, which causes a serious deterioration in the AF performance. In the proposed system, an adaptive digital filter (ADF) operates as a series compensator and compensates for the time-lag property of AF. The ADF requires no additional hardware, but for only a slight additional software. It was confirmed by simulation and experimental results that simple two-tap ADF is very effective for improving the AF compensation performance.