Fractional-Order Lead-Lag Compensation Control for Interleaved Buck-Boost Converters

As an important element of the renewable energy distribution generations, the modeling accuracy and control performance of the interleaved Buck-Boost converter directly affects the stability and efficiency of the renewable power generation. Based on the fact that the inductor and capacitance are fractional-order (FO) elements, the Buck-Boost converter is FO system. At present, most FO control strategy research has focused on the integer-order (IO) converters, which is inconsistent with the fractional order nature of converters. In order to improve the stability and dynamical performance of the FO interleaved Buck-Boost converter control system, a dual-loop control system based on the fractional-order lead-lag compensation control (FOLLCC) strategy is proposed. To begin with, the FO state space average model for interleaved Buck-Boost converter operating in continuous conduction mode (CCM) is established according to the FO calculus theory and state space average method. Then, the FOLLCC of the FO interleaved Buck-Boost is designed by using the peak current closed-loop control with inner current loop outer voltage loop. The impact of different FO controllers on the steady-state performance of the system is analyzed to improve the control effect. Using MATLAB for simulation, the simulation results show that the control system based on FOLLCC has shorter rise times, faster response speed, stronger robustness, and better dynamic performance. Finally, the experiments verify the effectiveness of the proposed approach.