Dynamic output feedback discrete time sliding mode control of sepic

DC-DC power converters are utilized widely in industrial applications such as active power factor correction, maximum power point tracking and power conversion. In addition to those applications, with the increase in demand of renewable energy production, and household electronical equipments that require DC voltage, makes the control of DC-DC voltage an important topic. The challenging aspect of the control of DC-DC converters can listed as the disturbance effects of the changing plant parameters such as inductance and capacitor, load variation, supply voltage fluctuation, changing output voltage demand, unmodeled dynamics. Robust control algorithms are required to mitigate the negative effects of the listed disturbances. Sliding Mode Control (SMC), being one type of robust control algorithm is especially preferred to control the plants having parameter uncertainty and matched uncertainty which is a disturbance that enters the system through the input channel. SMC is used in the problems where outside disturbance is an important consideration such as underwater vehicle position control and satellite orientation control. In general, conventional state feedback SMC design is straightforward and easy to implement. However, there is no straightforward way to design a state feedback SMC for the plants having non-minumum phase characteristics and invariant zeros and SMC design for those plants requires rigorous mathematical manipulations. State feedback SMCs also require all states to be available which requires a full state observer such as Kalman Filter or Luenberger Observer. Output Feedback Discrete Sliding Mode Control (ODSMC) is one type of output feedback Sliding Mode Control algorithm. The desing of ODSMC is straightforward and does not necessitates a state observer thereby shortening the design process. In this study, an ODSMC is design for a Single-Ended Primary Inductance Converter (SEPIC) converter and efficacy of the controller is validated through numerical simulations in Matlab/Simulink environment.