Robust Flatness-Based Control With Nonlinear Observer for Boost Converters

Abstract

DC–DC boost converters are widely used in different applications, such as electric transportation systems and telecommunications. A robust controller is required due to boost converter nonlinear behavior. Reducing the number of sensors in the control system is important. It leads to a lower cost system. This article presents sensorless flatness-based control and a nonlinear observer for a boost converter. Practically, it is difficult to build an exact mathematical model. Thus, online estimators are applied to estimate the modeling error and build a more realistic model. In addition, the output current and input voltage are estimated by the observer. As a result, the sensors of these two parameters are removed. The proposed controller is robust to variations in the input voltage and load resistance. A one-loop structure is implemented for the proposed controller to control the input current and output voltage. Because of the one-loop structure properties, high dynamical performance can be achieved. A reduced number of sensors and a high-bandwidth controlled system are the main contributions of this article. Simulation and experimental results are presented to confirm the effectiveness of the proposed control method.