D. M. E. Ingram & S.D. Round, "A novel digital hysteresis current controller for an active power filter", 2nd International Conference on Power Electronics and Drive Systems (PEDS 97), Singapore, 26-29 May 1997, Volume 2, pp 744-749.
An active power filter is used to eliminate current harmonics produced by nonlinear loads. This paper discusses a novel method of controlling a power inverter used to inject compensating currents into the power system. A digital signal processor performs the harmonic isolation and generates a digital reference current. A hysteresis current controller has been implemented in a field programmable gate array and generates the switching signals from this reference. This reduces the analogue circuitry and enhances the system's immunity to noise. This paper presents the results and discusses the performance of a small scale inverter under completely digital control.