Adaptive Finite-time Control of DC-DC Converter Feeding Constant Power Load for Fuel Cell Vehicle

Abstract

The converter instability caused by the constant power load directly affects the safety and reliability of the fuel cell power system. To improve the stability of the fuel cell converter, an adaptive finite-time controller is proposed in this paper, which not only has stronger robustness but also realizes the large-signal stability of the fuel cell converter. Firstly, considering the load uncertainty, the canonical form of fuel cell converter is obtained by coordinate transformation, and the nonlinear model of fuel cell stack and converter is derived. Secondly, the disturbance observer is used to observe the load variation to ensure that the output voltage of the converter can accurately track the reference value. Thirdly, because the fuel cell output voltage is determined by the load power, a fuel cell output voltage estimator should be designed to estimate the real-time output voltage of fuel cell. Finally, the robustness and effectiveness of the control algorithm are verified by simulations.