Design of a new multiple-loops linear controller for a three-phase series active voltage harmonic compensator

Voltage and current harmonics, which are injected in the utility by nonlinear loads, cause major problems that tend to deteriorate the power quality at the mains. To reduce such harmonics, active power filters (APF) are commonly employed. Whereas shunt APFs are used for current-type load, series APFs are applied to voltage-type load and allow both voltage and current harmonic compensation. In this paper, a new constant-frequency control scheme for a series APF is designed. The elaboration of the control law is based on a small-signal averaged model of the converter, computed in the (d,q) synchronous frame. The control scheme consists of multiple-loops PI controllers that ensure voltage regulation at the DC side of the filter, and voltage harmonic compensation at the AC side. The control system is implemented numerically using Matlab/Simulink tool. The performance of the proposed control approach is finally discussed through the obtained simulation results.