Study and Design a Strategy to Control High-Voltage Power Supply Based on PSM Technology on J-TEXT Tokamak

To energize the gyrotrons of the electron cyclotron resonance heating system, high-voltage power supply (HVPS) at 100 kV/60 A was built on J-TEXT tokamak. The HVPS was based on pulse step modulation (PSM) technology. This power supply has many advantages, including low energy storage and a short protective time in the event of a short circuit fault. In this study, we analyze and compare several common control strategies for PSM power supply. To enhance dynamic performance, the improved queue-up PSM control strategy was proposed. The control algorithm was generated using a controller based on parallel card interface extensions for instrumentation (PXI) technology, which conforms to the control, data access, and communication standard of the ITER. This controller also operates the modules of switch power supply. Experimental results show that the control system is effective and that the PXI controller can rebalance the output voltage and frequency in 60 μs when the module malfunctions under the improved system. Furthermore, the algorithm for the PXI controller is easy to develop and does not require much resources.