Research On Boost Converter For Fuel Cell Vehicle Based On Wide Band-gap Device

Fuel cell electric vehicle(FCEV)have the advantages of high efficiency,energy saving and environmental protection.Because the fuel cell has a wide output voltage range,soft output characteristics,and slow dynamic response,it cannot directly supply power to the motor controller,so it is bridged between the fuel cell and the motor controller using a Boost converter.Boost converter realizes the control of fuel cell output characteristics,it is one of the key components of fuel cell electric vehicles.The paper aims to develop high-power,high-reliability,high-efficiency,high-power density,high dynamic response speed for FCEV Boost converters.The FCEV Boost converter was deeply studied using wide band-gap power devices,interleaved parallel technology,coupled inductance technology,modeling and digital control techniques.Compared with Si power devices,wide band gap power devices have obvious advantages.The use of wide band-gap power devices can increase the efficiency and power density of FCEV Boost converters.In the interleaved parallel main circuit topology,the working principle of the four-phase interleaved parallel Boost converter topology is analyzed.The spatial state method is used to model and analyze the four-phase interleaved parallel Boost converter.The spatial state model,the spatial state average model,input and output transfer function,control and output transfer function are obtained.The power and reliability of the FCEV Boost converter can be improved by using the interleaved parallel technique.In the four-phase coupling inductance staggered parallel Boost converter,the working principle is analyzed,and the coupling inductance reduces the ripple current and improves the dynamic response.The coupled inductance technology is used to improve the efficiency,power density and dynamic response speed of the FCEV Boost converter.Finally,through simulation verification,the prototype of the four-phase interleaved parallel Boost converter with input 90-180V/300 A output 400V/25 kW was built and verified by experiments.