Tokomak designs use strong electromagnets to contain fusion plasma in a stable torus shape. The electromagnets are controlled using powerful, fast switching power electronics to control the electric field and stabilise the plasma.
IGBTs provide the ideal semiconductor to perform this function, with the latest IGBT range of 1700V 1400A half bridge modules providing efficient, high speed switching. These are typically fed from controlled rectifiers, providing a stable DC rail to supply the coil supplies. High power, air cooled controlled rectifier assemblies such as DSS3200BM-B6C-930 are manufactured from Thyristors with optimized losses for grid linked rectifier applications, that provide a highly controllable supply for the switching devices.
Other designs require high pulse power devices, that can deliver extraordinarily large currents over a short period of time. Our long history of providing pulse power devices for traction and HVDC applications placed us in an excellent position to provide wide diameter, fast turn on Thyristors that can meet these challenging requirements, whilst providing a highly reliable platform. The PT85 Pulse Power Thyristors were designed for laboratory experiments, and are now being used to support Fusion Energy research efforts globally.
Dynex has full control of the design and manufacture of our devices, so we are able to work collaboratively with researchers to optimise our devices to suit their application and support their research.
Our Power Assemblies Department can support the design of the whole mechanical arrangement for these converters, providing an electrical, mechanical and thermal design service.
Dynex Power Assemblies provided converter designs to support Fusion Energy efforts around the globe
In 2017 Dynex provided Tokamak Energy with a Merging Compression Power Supply
Merging compression is an efficient and robust method for plasma start-up which can achieve both high plasma current and high temperatures at fusion relevant densities. It involves the formation of plasma around two in-vessel poloidal field coils followed by a magnetic reconnection event after which the plasma can be compressed.
The power supply consisted of:
- Current 50kA / Volts 11kV
- Fibre optically controlled high voltage Thyristor Stack Assembly
- Capacitor bank 30mF/11kV
- Mechanically changeable flywheel diode with series resistance for resonance damping