Robust Control of DC-DC Boost Converter by using µ-Synthesis Approach

Boost converters are used in many renewable energy systems in order to interface a lower voltage source such as a solar array or battery to the dc input of a grid-connected inverter. The boost converter must be controlled in order to correct for the effects of variable input voltages and changing output loads. This paper develops an improved controller design method using a µ-synthesis approach. The goal is to achieve a low order controller that can be implemented at a reduced cost. This is an improvement over H∞ controllers that achieve robust performance with more complex realizations. Detailed simulation results for a wide range of parametric changes in the boost circuit environment confirm the benefits of the proposed method. The results are compared with a PI controller whereby it is shown that µ-synthesis provides improved performance compared to a conventional controller.