Research On The Feedback Control Of -100kV PSM High-Voltage Power Supply

To develop the electron cyclotron resonance heating(ECRH)system on J-TEXT tokamak,the J-TEXT laboratory developed a-100 kV /60 A PSM(Pulse Step Modulation)High Voltage Power Supply(HVPS).The ouput performance of this HVPS will influence the security and efficiency of the ECRH system to a great extent.This paper did some design and rearch on the output voltage measurement and feedback control system of the HVPS to decrease the output voltage overshoot and monitor the running condition constantly of the HVPS.To accomplish the measurement and acquisition of the HVPS output voltage,this article adopted parallelled RC voltage divider to convert the high voltage to transmittable signal.Based on the low voltage leg output of the voltage divider,this article designed the signal conditioning circuit?Voltage/Frequency(V/F)conversion circuit and electro /optic conversion circuit and achieved the isolated optical transimission of the low voltage leg output.To reduce the signal transmision time delay,this article accomplished the frequency/voltage conversion using software programe instead of hardware circuit and designed the frequency signal acquisition,data communication and monitor interface LabVIEW programe using the local controller of PSM HVPS.Test results showed the measurement system comfirmed to the designed function and parameter requirement with measurement precision ±1%,time delay less than 10?s and could be applicated to the HVPS output voltage waveform monitoring and feedback control.To analysis the cause reason of the HVPS voltage overshoot,this article made some analysis and simulation about the transient process of the PSM module circuit,summarized the cause of output voltage overshoot and analysed circuit parameter influences on the overshoot.To decrease the overshoot voltage and stable the output voltage without changing the module circuit parameters,this article designed the output voltage feedback control strategy based on the HVPS open-loop control stategy.Based on the above voltage measurement and feedback control strategy research work,a simulation model of PSM HVPS was built and PSM HVPS feedback control test was accomplished to demonstrate the control effect of the open-loop SM/PSM control strategy and feedback control strategy.Simulation and test resultes showed that the feedback control system could lower the output voltage overshoot to under 1% and stable the flat voltage under load variation effectively which provided important guarantee to the further ECRH experiment on J-TEXT tokamak.