Development Of A Novel Switching Power Module Based On The PSM Technology

The Electron Cyclotron Resonance Heating(ECRH)system is being upgraded on the JTEXT tokamak device.In order to complete the parameter adaptation of the original set of 100 k V/60 A Pulse Step Modulation(PSM)high voltage power supply(HVPS)and the new gyrotron,it mainly solves the problem of output voltage overshoot of HVPS,this article mainly focuses on the PSM power module research and design,based on DC bus voltage control,a new PSM module circuit topology and control method are proposed,it can greatly reduce the module output voltage overshoot.Besides,the development of 750 V/25 A module prototype and the simulated verification of multi-module operation are also accomplished in the thesis.Based on the existing PSM power module,the cause & size and influencing factors of the output voltage overshoot of the traditional modules are studied and analyzed,then the research and design of the new module scheme are carried out accordingly.By comprehensive consideration of the performance requirements,safety reliability and cost of the module,this paper uses a novel bus voltage control method and comes up a new PSM power module scheme,which can solve the problem of module output voltage overshoot.Moreover,the circuit structure and control system of the module are relatively simple and the cost is low.According to the proposed new module scheme,the development of 750 V/25 A module prototype is carried out.Firstly,the normal working process of the module is introduced,the selection design and parameter calculation method of the main circuit key components are studied and analyzed.Combined with the protection requirements of the module,the parameter design of the IGBTs and SiC MOSFET snubber circuits are analyzed.Secondly,considering electromagnetic compatibility,heat dissipation and space layout from two aspects of the main circuit and the control loop,the structural design of the module is accomplished.Finally,the hardware design of the module control system and program design based on DSP real-time operating system μC/OS-II are accomplished.Combined with the control requirements of the module prototype,the performance test is accomplished under normal and abnormal situation.The test results show that the new module scheme design method proposed in this paper is effective and feasible,the developed module prototype has good performance,which fully meets the design requirements.Based on the prototype parameters of the module prototype,a simulation model of the PSM HVPS is built to verify the suppression effect of the HVPS output voltage overshoot.The results show that high-voltage output overshoot can be suppressed to within ± 1 %,and is not limited by the rise time,which can significantly improve the performance of PSM HVPS.