Fixed-time Sliding Mode Control for Buck-Boost Converter

Abstract

Abstract To obtain stable state within the fixed time and reduce the influence of uncertain device parameters on the buck-boost converter, this paper proposes the fixed-time sliding mode control (FSMC) and fixed-time adaptive sliding mode control (FASMC). Firstly, we build the state-space average model on the basis of the continuous conduction mode (CCM) of the buck-boost converter. Secondly, the fixed-time sliding mode surface and FSMC are studied when the device parameters are known. By analyzing the Lyapunov stability, it has been proved that the system can reach a stable state within the fixed time, besides the maximum of the fixed time is merely determined by the parameters of the control strategy. Thirdly, when the system device parameters are unknown, the FASMC is developed ensuring the system can reach the adjacent domain of the equilibrium point within the fixed time. Finally, the effectiveness of the proposed control strategies was verified by the simulation experiments.