A robust digital current control method for active power filters

A robust digital current control strategy for active power filters using voltage-source converters is presented. The proposed control system is designed and implemented in the form of an internal model control structure and takes the presence of computational time-delay into account. As a result, it provides an effectively overshoot-free reference-to-output response. The stability of the closed-loop system has much lower sensitivity with respect to parameter uncertainties compared to the case when a conventional predictive controller is used. The experimental results obtained from a digital-signal-processor-based single-phase experimental active power filter are also reported.