Analysis, design and implementation of a fixed frequency PWM-based sliding-mode controller for quadratic buck converter

摘要

The DC-DC converters are well-known due to their nonlinear and time-variant nature. This paper addresses the investigation of a fixed frequency pulse width modulation (PWM) based sliding mode current controller applied to quadratic buck converter (QBC). The QBC is well-suited for very low voltage central processing unit (CPU) voltage regulator applications with high-step-down DC-DC conversion ratios. The sliding mode current control features the reference current profile generation, satisfaction of hitting, existence and stability conditions besides the selection of sliding surface parameters. The simulation of QBC is realised for 19 V~8 V/1V at 50 KHz using PSIM software. The experimental results are presented in order to validate the simulation results. The strength of this control strategy is analysed for both line and load regulations.