Switching power amplifiers (SPAs) have a wide variety of applications within the fusion science community, including feedback and control systems for dynamic plasma stabilization in tokamaks, inductive and arc plasma sources, Radio Frequency (RF) helicity and flux injection, RF plasma heating and current drive schemes, ion beam generation, and RF pre-ionizer systems. SiC MOSFETs offer many advantages over IGBTs including lower drive energy requirements, lower conduction and switching losses, and higher switching frequency capabilities. When comparing SiC and traditional silicon-based MOSFETs, SiC MOSFETs provide higher current carrying capability allowing for smaller package weights and sizes and lower operating temperature.
Eagle Harbor Technologies (EHT) designing, constructing, and testing a SiC MOSFET-based full-bridge SPA. EHT will leverage the proprietary gate drive technology previously developed with the support of a DOE SBIR, which will enable fast, efficient switching in a small form factor. The Helicity Injected Torus (HIT) team will test the SPA in a validation platform experiment. EHT will work with HIT to develop a specifications document to assure the SPA will be suitable for validation platform experiments. EHT will SPICE model, design the circuit board and select components. Once all of the materials are in house, EHT will build and bench test the SPA. The last objective is to begin the design of a complete helicity injector power supply based on the SPA that will be built and tested in a potential Phase II program.
These SiC MOSFET-based SPAs will allow for higher frequency switching (>1 MHz) capabilities at high power in a compact form factor and low switching losses. While this device is being designed for fusion science applications, similar devices are used in 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 switching power amplifiers have use in power converters including inverters, DC-DC converters, and active rectifiers.
EHT Switching Power Amplifiers and the EHT Arbitrary Pulse Generator were commercialized through this SBIR program. These SPAs are the drivers that allow for the development of solid-state neutral beam injector power supplies.