Finite States Modulated Model Predictive Control for Active Power Filtering Systems

This paper investigates the application of an improved Modulated Model Predictive Control strategy to active power compensators. The proposed control is able to retain all the advantages of a Finite Control Set Model Predictive Control whilst improving the waveform harmonic spectrum. In fact a modulation algorithm, based on the cost function ratio for different output vectors, is inherently included in the predictive control algorithm. In particular the case of a Shunt Active Filter is investigated and the converter topology, its analytical modeling and its control implementation are described in details. The cost function-based modulator is introduced and its effectiveness on reducing the current ripple is demonstrated. The proposed approach provides a straightforward and effective single loop control solution, maintaining an excellent dynamic performance despite the modulated output and it is self-synchronizing with the grid. Significant results obtained by experimental testing are reported and commented.