LAUSR

A 100-kV/60-A high-voltage power supply (HVPS) based on pulse step modulation (PSM) technology has been established on J-TEXT Tokamak to feed the electron cyclotron resonance heating (ECRH) system for plasma heating. To fulfill the waveform monitoring, feedback regulation, and protection requirements, a high speed and precision voltage measurement and transmission system with high voltage and ground isolation is designed and applicated to the HVPS. A feedback regulation method is proposed to not only suppress the output voltage overshoot during startup of the HVPS operation but also ensure the precision of the output voltage on flat stage under the change of load conditions. Experiment results on the J-TEXT HVPS show that the voltage measurement system behaves well both in precision (measurement error <0.5%) and response time ( $< 5~\mu \text{s}$ ). The feedback regulation method can reduce the overshoot voltage to less than 1%.