Research On DV/dt Immunity Of A MOS Gate-Controlled Pulse Power Device

In the trend of continuous development of repetitive pulse power technology,the technical requirements of pulse power switching devices on pulse power switching devices are becoming more and more stringent.Among them,due to the performance characteristics of high voltage and high frequency of the repetitive pulse power technology.The reliability of the switching device as a power conversion hub is receiving more and more attention.This research object MOS gate-controlled thyristor?MCT?has the advantages of high input impedance of MOSFET and high current surge capability of thyristor,which has become a potential pulse power switching device.However,it is easily affected by high voltage change rate dV/dt during the high-voltage and fast repeated operation of the capacitive energy storage pulse power system,which leads to false trigger and greatly reduces the reliability of the system.This article aims to study the dV/dt immunity of the MOS gate-controlled thyristor?MCT?,in order to make a good guide for the design of high dV/dt immunity of the device.The main contents of this article are as follows:1.Briefly introduce the principle,development history and development trend of pulse power technology.The performance differences of various pulse switching devices are compared and studied,and the research status of the dV/dt immunity of the MCT is described.2.Theoretical modeling and analysis of the capacitor energy storage pulse power system,mastered the device performance requirements for high current rise rate di/dt and high peak current I_peak,and established the direction for device optimization.The basic structure and working principle of the thyristor and MCT are analyzed,and the dV/dt immunity of the thyristor is studied,which lays a foundation for the research of the dV/dt immunity of the MCT.3.The theoretical model of the dV/dt immunity of the MCT device is established,and the key influencing factors of the dV/dt immunity such as the doping concentration of the P-well region and the N-well region are mastered.Subsequently,without changing the basic performance of the device,a cathode-short MOS gate-controlled thyristor?CS-MCT?with higher dV/dt immunity was proposed.The high dV/dt resistance of the CS-MCT device is studied by simulation and experiment.The research results show that the dV/dt immunity of the CS-MCT device is increased by about 50%-80%compared with the traditional MCT device.At the same time,the contradictory relationship between the influencing factors of dV/dt immunity and the dynamic and static parameters of the device is analyzed,and the compromise optimization direction between the dV/dt immunity and the pulse performance of the device is obtained.At the same time,for CS-MCT,it was found that sub-threshold current played an important role in reducing dV/dt immunity,and then established its influence mechanism,and was verified by simulation and experiment,which provided more comprehensive theoretical guidance.