Feedforward-Double Feedback Control System of Dual-Switch Boost DC/DC Converters for Fuel Cell Vehicles

Abstract

DC/DC converters for fuel cell electric vehicles need not only high boost ratio and high efficiency, but also strong anti-jamming capability. Therefore, it is especially important to devise a control method with strong robustness under the premise of an appropriate topology. In this paper, a simple dual-switch boost converter topology is adopted. We use the state space averaging method to build a small signal model, and based on this model, we propose a feedforward-double feedback control system for continuous conduction mode (CCM) mode. Simulation and experimental results show that the proposed feedforward-double feedback control system improves the robustness of the system while ensuring a high boost ratio and efficiency, and solves the problem of weak output characteristics of fuel cells. The control effect is similar to the sliding mode control, which is known for its robustness, while the rise time of step response is only 1/10 of that of the voltage feedback control system. When the output voltage of the DC/DC converter is 55 V, the DC/DC converter using feedforward-double feedback control system is more robust than the voltage feedback control system under sudden change of load.