Dynex Semiconductor - High-Power Electronics and Sub Assemblies for Rail and Trackside Applications

Dynex Semiconductor is one of the world's leading designers and manufacturers of high-power silicon products. Its components and power assemblies deliver and manage electric power on land, sea and air. Dynex Semiconductor has been manufacturing high-reliability power semiconductor products in Lincoln, UK, for more than 50 years, trading under the more familiar names of AEI Semiconductors, Marconi Electronics Devices and GEC Plessey Semiconductors.

Many of Dynex Semiconductor's products are still operating worldwide after more than 40 years in a wide variety of applications, including excitation, HVDC, PFC, tap changers, SVC and FACTS, traction drive systems and high-power inverter and converter products utilising Dynex rectifier diodes, thyristors, GTOs and more recently IGBTs.

Thyristor, GTO and IGBT power assemblies

Dynex Semiconductor has many years of applications experience, which has developed from working very closely with customers who have a broad field base. The company's semiconductor devices are being used worldwide in traction drive and power supply systems for a wide range of AC and DC systems. Its 150mm converter thyristor provides the highest current capability available, and devices are operational as individual components rated to 8.5kV. The power assembly capability allows Dynex Semiconductor to integrate its devices into power systems with much higher voltage ratings, and 25kV line rectifiers and switches are operating in the field.

Dynex Semiconductor's continued commitment to its GTO products provides continuity of supply for GTO-based traction drive systems, and it has a number of spares, repairs and refurbishment contracts currently in operation.

Traction drive power electronics, trackside rectifiers, HV disconnect switches and auxiliary power supplies

Previous projects have included:-

• GTO based air-cooled drive assemblies for EMU and diesel electric units
• IGBT-based drives for main propulsion and auxiliaries
• High-power diode rectifiers
• Oil-cooled and phase change-cooled inverters and chopper assemblies
• Auxiliary power supply sub systems

These systems have been supplied into safety critical applications and Dynex is familiar with the regulatory requirements to achieve this. The emphasis is on reliability so Dynex implements design enhancements to improve the longevity of its sub assemblies, and it works with customers to understand specific application issues which are not immediately obvious.

Dynex can offer standard power assemblies such as SCR and diode rectifiers, for ratings from kilowatts up to many megawatts, but it can also offer a high degree of customisation where there are specific requirements to be met, for example restricted space, high voltage isolation, partial discharge, oil cooling and phase change cooling. Dynex also has a range of standard thyristor driver boards that can be customised for special requirements such as fast switching speeds in pulsed power switches.

Specialist high-power testing equipment

To ensure the high reliability of its products Dynex has also developed the capability to construct custom test equipment, which will verify the correct operation of high-power systems. Where there is a requirement for routine high-power testing, or even type testing, Dynex can offer the option of using its facilities to test on a customer's behalf or designing equipment for customers to install on their own premises. These systems will range from device parametric testers to system simulators, and they operate within customer defined specifications. The smallest field-based thyristor and GTO portable test systems can be used by maintenance crews, and the largest room-sized systems are fixed.