Current-sensorless robust sliding mode control for the DC-DC boost converter

A current-sensorless PWM-based robust sliding mode controller is proposed for the DC-DC Boost Converter, a nonminimum phase system that presents major challenges in the design of stabilizing controllers. The development of the controller requires the measurement of the output voltage and the estimation of its derivative. An extended state observer is developed to estimate a lumped uncertainty that comprises the uncertain load and input voltage, the converter parasitics, and the component uncertainties, and also to estimate the derivative of the output voltage. A linear sliding surface is used to derive the controller that is simple in its design and yet exhibits excellent features in terms of robustness to external disturbances, parameter uncertainties, and parasitics, despite the absence of the inductor current feedback. Also, a simple procedure to select the controller gains is outlined. The robustness of the controller is validated by computer simulations.