Design Of High Power Density Low Voltage High Current Three-phase Inverter

With the development of national economy,China has become the world’s largest importer and second largest consumer of crude oil.The extensive use of crude oil and other fossil fuels has brought many problems such as energy security and ecological environment deterioration.With the popularity of green environmental protection and the development of new energy technology,new energy instead of fossil energy has been the general trend,especially in the automotive,aerospace and construction machinery industries.The replacement of oil-fired internal combustion engines by electric motors is accelerating.In order to replace the internal combustion engine with the motor,the core technology is battery,motor and electric control,and the inverter is the core of the electric control system.The content of this paper revolves around the low voltage and high current inverter,firstly expounds its application and future market in the field of electric vehicles,electric aircraft and electric engineering machinery,and analyzes its technical characteristics.Based on its low voltage and high current application scenarios,special analysis and design are needed in the aspects of loss,circuit structure and heat.Firstly,based on the application scenario of small unmanned aircraft,this paper introduces the requirements of the designed inverter under the condition of high power density and low voltage and large current,and introduces the loss source of power MOSFET,and then deduces and calculates the loss of power MOSFET.And design the inverter circuit.By the way of cascade wiring to reduce the parasitic inductance,the power MOSFET voltage stress during switching action has been reduced.In order to meet the demand of large current,the main power plate adopts the material of high glass transition temperature and the thick copper PCB.Then,design the mechanical structure of the whole inverter,and analyze the heat dissipation of the inverter by establishing the steady-state thermal resistance model of the inverter.According to the results,design the radiator,and the thermal simulation is verified by Flo THERM.According to the above of this article,the inverter prototype is welded and assembled,and build the test bench of the inverter,conduct the experiment.The performance of the inverter system are verified by experiments.