Super twisting sliding mode based voltage control of DC-DC SEPIC converters

This paper proposes a Super-Twisting Sliding-Mode Control (STA-SMC) technique for voltage regulation of the SEPIC converter. The control error is defined as the error between the output and reference voltages. The error function is used as the sliding variable and the super twisting algorithm is integrated to reduce the chatterring. The duty cycle is generated by the integration of the sliding mode and super twisting algorithm. The effectiveness of the proposed method is validated experimentally on a SEPIC converter prototype. Steady-state results demonstrate that the controller successfully regulates the output voltage to its reference under buck and boost operating modes. Dynamic test results verify that the proposed controller is capable of output voltage regulation under variations in input voltage, reference voltage, and load resistance. In addition, the proposed STA-SMC method maintains stable voltage regulation despite operation mode transitions between buck and boost modes. It is also observed that the system variables don’t include chattering.