Power Semiconductors for Rail Traction

SiC Power Modules, high power IGBT Modules, GTOs, Fast Recovery Diodes, Phase Control Thyristors, Rectifier Diodes or customised power assemblies.

SiC technology offers reduced switching losses and high-frequency operation, providing opportunities to improve converter efficiency, reduce cooling requirements and increase power density.

GTO's are essential for efficiently controlling power flow during braking, enabling the conversion of kinetic energy back into electrical energy that can be fed back into the power grid, or reused thereby reducing overall energy consumption.

GTOs act as high-power switches that control the current flow between the traction motors and the electrical system. By turning on and off at high speeds, they allow precise control of the braking energy conversion process.

GTOs can handle high voltages and currents, making them ideal for the demanding conditions of train operation. Their ability to turn off rapidly allows for better control of the braking process, improving overall system efficiency.

GTOs are robust and can endure the repetitive and harsh conditions typical in railway systems, contributing to the reliability of the regenerative braking system.

Modern regenerative braking systems often use a combination of GTOs and other semiconductor devices like IGBT modules to optimize performance. GTOs are preferred in high-power applications due to their capability to handle larger currents.

Traction Applications:

For freight trains carrying heavy loads, GTOs provide the necessary power handling capabilities to manage the large amounts of energy involved in braking.

GTOs are commonly used in high-speed trains where precise and efficient braking is crucial.

Yes. Dynex supports the refurbishment and life extension of established rail traction systems with a range of high-power semiconductor technologies, including GTOs, thyristors, diodes and IGBT modules. Where original components are obsolete or difficult to source, Dynex engineers can work with customers to understand the electrical, thermal and mechanical requirements and identify a suitable replacement or engineered solution.

Dynex can also provide customised power assemblies, helping customers address obsolescence, converter upgrades and the continued support of ageing rail fleets.

A gate turn-off thyristor (GTO) is a high-power semiconductor device. It works by acting as a switch in high voltage circuits. Like a thyristor (SCR Silicon-Controlled Rectifier) it has 3 terminals; anode, cathode and a gate terminal. Both a GTO and SCR have a controlled turn on function via the application of a  positive pulse to the gate terminal, but the GTO also has controlled turn-off function by the application of a negative pulse to the gate terminal. An SCR only turns off when the forward current drops below the threshold holding current  The turn-off time is typically more than 10 times faster than for an SCR (silicon-controlled rectifier) thyristor.

Yes. Obsolete GTOs and IGBTs in older rail traction systems can often be replaced or supported as part of a refurbishment or life-extension programme. Dynex offers GTOs, high-power IGBT modules and associated power semiconductor technologies for established traction platforms.

Where a direct replacement is not available, Dynex engineers can assess the original device and application requirements including voltage, current, switching characteristics, thermal performance and mechanical compatibility to help identify an appropriate replacement or engineered solution.

This capability can help rail operators and refurbishment specialists manage semiconductor obsolescence, extend converter service life and keep established fleets operational for longer.

Yes. Dynex can design and manufacture customised power assemblies for rail traction and power conversion applications, combining suitable semiconductor devices with the electrical, thermal and mechanical components required for the application.

Solutions can support traction converter refurbishment, propulsion upgrades, auxiliary power systems, rectification and obsolescence management. Dynex engineers work with customers to understand their system requirements and develop an assembly suited to the required electrical performance, cooling, mechanical constraints and operating environment.

This capability enables Dynex to support customers from individual power semiconductor selection through to an engineered power assembly, for both new rail projects and the life extension of existing fleets.

The choice of power semiconductor directly affects conduction losses, switching losses and thermal performance within a traction converter. Selecting IGBT, SiC MOSFET and diode technologies with the appropriate voltage, current and switching characteristics can reduce power losses, improve thermal management and increase overall converter efficiency. Higher-efficiency devices can also enable higher switching frequencies, potentially reducing the size and weight of associated cooling and passive components.

For modern rail systems, SiC MOSFET technology can provide particularly low switching losses and high-frequency operation, while high-power IGBT modules remain well suited to many demanding traction applications where high current capability, robustness and proven reliability are key requirements.

Dynex application engineers can support customers in selecting semiconductor technology suited to the electrical, thermal and mechanical requirements of their traction system.