Sliding coefficients estimation for fixed frequency sliding mode control of boost converter

The paper presents and analyses a control system for the Boost converter in which sliding mode control and classical PWM are combined into a fixed frequency sliding mode control system that emphasizes the advantages of both control methods. This leads to good responses of the power converter in dynamic and in steady-state regime, but a proper estimation of the control parameters is needed. Thus the fixed frequency sliding mode control is analyzed, the control function, the existence conditions and the stability conditions are calculated. Based on this calculations the conditions for the sliding mode coefficients are determined and interpreted for design purposes. Finally a algorithm for the estimation of sliding mode coefficients is proposed and the stated considerations are verified through simulation.