A feedforward compensation based decoupling control strategy for grid-connected inverter with LCL filter

Abstract

There are complicated coupling terms between d-axis and q-axis in the mathematical model of grid-connected voltage-source inverter (VSI) with LCL filter in synchronous reference frame. As to this, a new feedforward compensation based decoupling control strategy, which is realized by making use of the equivalence transformation principle to eliminate the interaction caused by the coupling terms gradually by feedforward compensation, is proposed in this paper. Proposed decoupling control is verified by designing the simulink model of dual closed current loop control strategy according to the decoupling result. Proposed control strategy can not only realize the active and reactive power control independently by eliminating the coupling term between d-axis and q-axis, but also effectively enhance the quality of grid-connected current and improve the dynamic performance. It is verified by the simulation results.