Inverse system optimal control of interleaved boost converters

When compared with the conventional boost converter, the interleaved boost converter (IBC) has the advantages of low current stress. Thus, they have been widely used in DC microgrids. However, the IBC is a multiple input single output (MISO) high-order nonlinear system. To simplify the controller design, a reduced order model of an interleaved boost converter is proposed in this paper. By selecting an appropriate output function, the nonlinear reduced order system is transformed into a pseudo-linear system through the inverse system theory. Then an optimal controller is designed based on the linear quadratic regulator (LQR) theory. As a result, the output voltage can track the reference value. In addition, a current balance controller is designed to balance the interphase inductor current. Simulation results of a 3-phase IBC show that when compared with PI control, the proposed control strategy has better regulation performance. Finally, the correctness and effectiveness of the proposed control strategy are further verified by experiment on 2-phase IBC.