Robust control for non-minimum phase and cross-regulation in single-inductor dual-output boost converter

Single-inductor dual-output (SIDO) boost converters are used extensively in modern power systems because of their small circuit volume and high efficiency. However, SIDO boost converters exhibit non-minimum phase property, and the coupling of the inductor current results in coupled dual outputs leading to cross-regulation, which seriously affects the dynamic performance and stability of the system. To settle the non-minimum phase issue and suppress the cross-regulation of SIDO boost converters, proposed herein is a robust control method, which combines the exact feedback linearization (EFL) theory, adaptive technology, and sliding mode control (SMC) method. A nonlinear mathematical model is established, and a set of output functions for full linearization are constructed based on EFL theory. Furthermore, the output functions are linearized, and two single-input single-output linear subsystems are obtained. The SMC technologies are used to control the linear subsystems to improve the robustness of the system, and an adaptive mechanism is adopted to update the sliding mode switching gain to reduce chattering. Furthermore, the global asymptotic stability of the control system is proved based on the Lyapunov theory, and the robustness of the closed-loop system is verified. Simulation and experimental results show that the proposed approach provides better dynamic regulation performance compared with the existing method. This paper proposes a robust control strategy combining exact feedback linearization (EFL) and adaptive sliding mode control (ASMC) for a SIDO boost converter. On the one hand, EFL helps to establish the linear sliding mode function and solves the non-minimum phase problem. On the other hand, the invariance of sliding mode to uncertainty can be used to reduce the dependence of EFL on an exact mathematical model and improve the robustness against disturbance and unmodeled dynamics. On the third hand, adaptive technology can update the sliding mode switching gain in real time to reduce chattering. The proposed control strategy is extending to other SIDO DC-DC converters easily and providing a reference for the controller design of SIMO DC-DC converters.image