Considerations of a Fully-Digital-Controlled Active Filter for Installation on Power Distribution Systems

This paper presents a DSP-controlled shunt active filter for harmonic termination of a power distribution line. The purpose of the active filter based on voltage detection is to damp out harmonic propagation caused by line inductors and shunt capacitor for power factor correction. However, time and phase delays inherent in the control circuit of the active filter might lead to poor harmonic damping performance. The hardware and software designs are important for achieving stable operation and satisfactory damping performance. This paper provides the details of design and implementation of a fully-digital controller for the active filter. Experimental results verify the viability and effectiveness of the DSP-controlled shunt active filter.