Development Of Frequency Conversion Current Pulse Power Supply Prototype For J-TEXT Tokamak Magnetic Perturbation

Tearing mode(TM)is a typical MHD instability in magnetic confinement fusion research,which affects the safe operation on tokamak device.An external resonant magnetic perturbation(RMP)can control TM effectively.The external RMP has different effects on TM such as stabilization and destabilization in the different phase intervals of TM rotation.Therefore,the power supply of DRMP coils output requirements are as follows: the output current is ±3000A with the rapid rising and falling edges less than 100?s,the frequency range is 1kHz to 5kHz,current response time is within 10 ms.In this paper,according to the demand of real-time feedback control of TM,a main circuit topology and control system of frequency conversion pulse power supply is designed.The main circuit includes a rectifier circuit,a filter circuit,an inverter circuit,and a resonant circuit.The control circuit get the working frequency by detecting magnetic island phase in real time.The current loop control method is used to control t he amplitude.In order to achieve the output current with rapid rising and falling edges,the load inductance is resonant with the capacitor through the IGBT reverse parallel diode.Then,based on theoretical analysis and simulation,a prototype of frequency conversion pulse power supply is built.The selection of thyristors and IGBTs,the filter circuit design,the laminated busbar and RCD snubber circuit design,the calculation of resonant capacitor parameters are included in the process of building.Due to loop inductance,the output current cannot climb to maximum amplitude instantaneously.A high power and low parasitic inductance resistor is designed by theoretical analysis and simulation.Its frequency characteristics,thermal characteristics and so on are verified through experiments.As a rectifier dummy load is used to increase the bus current amplitude first.And then H-bridge inverter circuit works.The graphite resistor is applied in power supply and gets achieved good results.Finally,a power supply prototype is designed,and the experiment is carried out in this paper.The power supply can output ±1300A current with the rapid rising and falling edges about 40?s,and the working frequency meets the physical requirements.A high power and low parasitic inductance graphite resistor reduces current response time greatly.The feasibility of the design scheme is verified and the expected target is achieved.It is a key reference that the frequency conversion pulse power supply is applied on tokamak.