Robust control of mismatched buck DC–DC converters by PWM-based sliding mode control schemes

• Published in: Control engineering practice 2019-03, Vol.84, p.183-193
• Main Authors: Pandey, Sanjeev Kumar, Patil, Sanjaykumar L., Ginoya, Divyesh, Chaskar, Uttam M., Phadke, Shrivijay B.
• Format: Article
• Language: English
• Subjects: Buck converter; Disturbance observer; Multiple surface sliding control; Sensorless control; Sliding mode control; State and disturbance observer
• ISSN: 0967-0661; 1873-6939
• DOI: 10.1016/j.conengprac.2018.11.010

In this paper, two control methods are proposed to control mismatched dc–dc buck converters. In the first method, called Method I, a multiple surface sliding mode control is proposed to handle mismatched load uncertainty. A major problem associated with multiple surface sliding mode control viz. ‘explosion of terms’ is handled by a disturbance observer. Another method, Method II, based on simultaneous state and disturbance observer is proposed as a further improvement over Method I in terms of sensor requirement. The practical stability of the proposed schemes is proved. The performance of both the methods are assessed for regulation and tracking of output voltage under various uncertainties and is compared with a method based on extended state observer. It is shown by simulation and experimentation that the transient and steady state performance of both the controllers are satisfactory. •Two new control methods are proposed to control a mismatched buck dc–dc converter.•One of the control methods overcomes the problem of ‘explosion of terms’s associated with multiple surface sliding control as well as it reduces the requirement of load current sensor.•In the second method, a simultaneous state and disturbance observer is proposed so as to save on load current as well as inductor current sensors.•Both the control methods are validated by simulation and experimentation.•Both methods can regulate the output voltage and can track the desired reference voltage.