A High Voltage Fast Switching Power Module for Active Control of Magnetic Fields and Edge Plasmas Currents in Fusion Validation Platforms

Fast, reliable, real-time control of plasma is critical to the success of magnetic fusion science. Fast feedback and control driving high current supplies is needed to mitigate instabilities in all experiments as well as disruption events in large scale tokamaks for steady-state operation. In order to rapidly change the current in a coil, high voltage is required. The high voltage solid-state switches on the market today do not take advantage of recent advances in solid-state switching. Silicon carbide (SiC) MOSFETs offer many advantages over IGBTs including lower drive energy requirements, lower conduction and switching losses, and higher switching frequency capabilities; however, these devices are limited to 1.2-1.7 kV devices. As fusion enters the long-pulse and burning plasma eras, overall efficiency of power switching will become important. General Statement of How This Problem is Being Addressed: Eagle Harbor Technologies (EHT), Inc. is planning to develop a single-board high voltage SiC MOSFET module that operates at 10 kV. This switch module will utilize EHT gate drive technology, which has previously demonstrated the ability to increase SiC MOSFET switching efficiency. The module will allow EHT and other researchers to more easily develop high voltage switching power supplies at lower cost and more rapidly. What is to be done in Phase I? EHT is partnering with the High Beta Tokamak group at Columbia to develop detailed high voltage module specifications, to ensure that the final product meets the needs of the fusion science community. During the Phase I, EHT will design, build, and test a proof-of-concept (POC) single board module including the isolated control voltage. With the data from the POC module, EHT will begin the preliminary design of the prototype to be constructed in a potential Phase II program. Additionally, EHT will work with Columbia to design a high voltage system for fast plasma control to be tested at Columbia in a potential Phase II program. Commercial Applications and Other Benefits: The final module will remove the complexity of developing high voltage switching power supplies as well as take advantage of the latest advantages in solid-state switching technology to allow for efficient switching. The simplicity and efficiency of this module will be important for feedback and control systems developed by the fusion science community including the Validation Platform experiments and the long-pulse burning plasma experiments. While this module is being designed for fusion science applications, similar modules could simplify and improve the efficiency of devices built for other areas including linear particle accelerator supplies, high voltage ion implantation supplies, RF cyclotron power supplies, high power pulse width modulation (PWM) amplifiers, and high power trigger systems. Additionally, these high voltage modules have use in power converters including inverters, DC-DC converters, and active rectifiers used on electric trains, photovoltaic and wind power plants, and other industrial applications. Key Words: SiC MOSFET, efficient switching, high voltage solid-state, series stack