Extended State Observer-Based Control of DC-DC Converters for Fuel Cell Application

Due to the nonlinear volt-ampere characteristic of fuel cell (FC) stack, a dc-dc power converter is essential to be interfaced, to regulate a stiff dc bus to properly power the load. In this article, a robust controller based on extended state observer (ESO) is proposed for a dc-dc interleaved boost converter for FC application. The proportional-integral (PI) control is also designed for comparison. By rewriting the PI control law as the unified form of disturbance observer-based control, it is revealed that the PI control in fact uses the integral action as the disturbance estimation. Then, a theoretical study is conducted to fairly evaluate and compare the performance of these two controllers. The results show that the proposed controller has superior performance to the PI controller, without the need of extra sensors. Simulation and experiment results demonstrate the effectiveness of the proposed controller.