Hybrid Active Switched Inductor DC-DC Converter With Common Ground and Suppressed Voltage Oscillation for Fuel Cell Vehicles

Abstract

In the pursuit of greener and more sustainable transportation solutions, fuel cell vehicles (FCVs) have widely emerged. The dc-dc converter regulates the variable output voltage of the fuel cell and acts as a key component of FCVs. Hybrid active switched inductor (HASL) dc-dc converters are widely used for FCVs due to their low voltage/current stress on power devices, wide voltage-gain range, simple design, and control. In existing HASL converters, during theoff-mode, the resonance between the drain-to-source capacitor and inductor results in a large voltage across the switches. This article proposes an improved high step-up voltage gain HASL dc-dc converter, eliminating this resonance. The proposed converter is derived by integrating an ASL cell with a switched capacitor cell. During theoff-mode operation of the proposed converter, the voltage across devices is supported with capacitors of a switched capacitor network, mitigating resonance and reducing voltage stress. The operating principles and steady-state analysis of the proposed converter are discussed, and design details are presented. A laboratory prototype of 600 W for voltage step-up from 30 to 330 V is developed and experimentally validated.