Research Of High Power Density Driver And Hybrid Energy Storage Technology For Fixed UAV Electromagnetic Launcher

With the development of information and intelligence,UAVs will play a more and more important role in the future battlefield.The takeoff of unmanned aerial vehicle(UAV)is the most important part of its application,which directly affects the safety and combat performance of UAV.Electromagnetic launch is a new type of fixed wing unmanned UAV take-off mode,which can realize continuous ejection and take-off of UAV in a short time,controllable acceleration in the process of ejection,and a wide range of adaptation for UAV types.UAV electromagnetic catapult requirements good mobility,small volume and light weight,in order to meet the rapid movement of different battlefield environment.In this paper,aiming at the UAV electromagnetic catapult for mobile applications,research for driver and energy storage of ejection system has been made.Put forward to use Silicon Carbide Metal-Oxide-Semiconductor Field Effect Transistor(SiC MOSFET)based driver and super capacitor hybrid energy storage system can reduce their size and weight,effectively enhance the maneuverability of UAV electromagnetic catapult.Firstly,this paper introduces the system structure of electromagnetic launcher,analyzed the characteristics of electromagnetic launcher.According to the characteristics of high current,short working time,the proposed new power device of SiC MOSFET to reduce driver's loss,reduce the weight of the heat sink,in order to improve the power density of the drive scheme.Considering the maximum current limitation of the SiC MOSFET module at present,this paper proposes a parallel drive mode to meet the requirements of high current output of the system,and can increase the maintainability and redundancy of the system.At the same time,according to the working characteristics of electromagnetic launcher with fixed timing,a hybrid energy storage system with the super capacitor and battery is put forward,with the super capacitor as the intermediate energy conversion device,the battery as the main energy source,achieve high power density energy storage device.Secondly,the characteristics of SiC MOSFET work in high temperature were studied,a design has been proposed to increase the temperature of junction standard,this can reduce the heat sink,which reduce the volume and quality of drive.By comparing the loss of SiC MOSFET based and IGBT based driver,the results show that using SiC MOSFET can improve the power density of the driver.Thirdly,according to the circulation problem in parallel driver system,this paper analyzes the characteristics of circulation affect by the two Connection way that include independent power supply mode and single power supply mode.the circulation feedback circulation was put forward to suppress the independent power supply parallel drive mode.Connecting the inductance to suppress the circulation of single power mode was put forward.The effectiveness of the proposed scheme is verified by experiments.Finally,according to the working characteristics of pulse electromagnetic catapult with fixed timing,the hybrid energy storage system with super capacitor and batter has been put forward,using ejection time to prepare for a super capacitor charging;in ejection time,super capacitor separately power the electromagnetic catapult strategy.The battery uses a Buck circuit to charge the super capacitor for constant current,and the super capacitor uses the Boost circuit to discharge with constant voltage.The feasibility of the proposed hybrid energy storage system is verified by simulation.