DSP based control of shunt active power filters for global or selective harmonics compensation

This paper presents the study of a shunt active power filter which compensates all or a specified mains current harmonics generated by a typical nonlinear load. The control is mixed and use a digital signal processor (DSP TMS320C40). It allows to test and validate easily different current or DC voltage control algorithms. A fundamental positive detector is realised to enlarge the working of the well known pq algorithm to several asymmetric conditions taken into account time delays. The system is investigated analytically as well as experimentally. The obtained results are presented and discussed to prove the effectiveness of the design and control strategy.