A Source-Current-Detected Shunt Active Power Filter Control Scheme Based on Vector Resonant Controller

A shunt active power filter (APF) with current detection at the source side is considered as a closed-loop system from the view of the whole power distribution system, which is expected with better harmonics filtering performance compared with the one with load current detection. The conventional source current detection control scheme can be mainly grouped into two types: 1) current-source-based (CS) scheme and 2) power-balance-based (PB) scheme. As introduced in this paper, the CS scheme has good dc-voltage regulation, but it bears inevitable conflict between filtering performance and system stability, whereas the PB scheme has excellent stable filtering performance, but it bears great influence on the dc voltage in the transient state. In this paper, a novel source current detection control scheme is proposed, which reserves the advantages of conventional schemes and, meanwhile, avoids their limitations. The proposed scheme employs a vector resonant controller, with which the shunt APF performs as an equivalent multiband rejection filter that series between nonlinear loads and the grid source, blocking selected harmonics components from the load side flowing into the source side. The proposed scheme is simple in structure, is needless of a harmonics extraction algorithm, and shows good stable and transient performance. Finally, the conclusions obtained in this paper are validated through experiments on the laboratory prototype.