The global demand for energy can't be met using current green technology. The only promising way to solve the energy crisis with low environmental burden is fusion, an inexhaustible fuel source. Progress in technology has created hope that fusion energy will become a key part of global energy production. Scientists have been trying to harness fusion energy to combat climate change by using devices such as Tokamaks to create and confine clouds of plasma made up of positively and negatively charged ions.
The role of Dynex power electronics in fusion energy development
Examples of power electronics includes specialised converters for the transforming stage between the power source and power supply output, fast switching power electronics to control electric fields and stabilise the plasma in Tokamak designs, and air-cooled controlled rectifier assemblies providing a highly controllable supply for switching devices.
Dynex have already provided power converter designs to support Fusion Energy research efforts around the globe.
A vertically integrated supply chain enables us to understand our power semiconductors and their performance, as well as tailor our devices to the specific requirement of the application. This is especially relevant for Fusion research, where often the best possible device is not available on the market. We work collaboratively with our partners to optimise our devices to suit their application requirements and support their research.
Our Power Assemblies department can support the design of the whole mechanical arrangement for these power converters, providing an electrical, mechanical and thermal design service.
Power Assemblies design service includes considerations for:
- High voltage series devices switching on synchronously
- High di/dt operation at large pulse currents
- Management of high electric fields
- Gate drive isolation to earth potential
- Long term isolation integrity and partial discharge
IGBT half bridge modules for high speed switching
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. IGBT modules 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 field coils.
Air cooled controlled rectifier assemblies
High power, air cooled controlled rectifier assemblies are manufactured from Thyristors with optimized losses for grid linked rectifier applications, that provide a highly controllable supply for the switching devices.
Pulse power 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 places 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. For example, devices such as the PT85 Pulse Power Thyristors were designed for laboratory experiments, and are now being used to support Fusion Energy research efforts globally.
Example of application specific design - Tokamak Energy provided 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
Dynex engineers are engaged in providing tailored power assemblies for fusion energy. Dynex are also part of several hydrogen production projects powered from grid distribution.
For more information, contact us to arrange a meeting with our team at powersolutions@dynexsemi.com