Siemens and Infineon improve efficiency of on-board power systems
Siemens Mobility and Infineon Technologies AG have developed new auxiliary converters (HBU) to make vehicle electrical systems with power semiconductors based on silicon carbide (SiC) more efficient and save energy. Siemens Mobility uses the new converter for various trains. As a result, they should be more maintenance-friendly, reliable, economical and, above all, power efficient.
Auxiliary converters are the critical link between connected consumers and the vehicle power supply, as they supply power to onboard systems such as heating and air conditioning, but also power outlets to charge a phone. Using silicon carbide (SiC) semiconductors for the power electronics, the size and weight of the Siemens auxiliary converters have been drastically reduced.
“With SiC, we achieve higher switching speed as well as efficiency to reduce the size of transformers, capacitors, cooling elements and the housing unit.”, said Dr. Peter Wawer, President of Infineon’s Industrial Power Control Division. “The advantages of this semiconductor material are evident and are now being leveraged in rail-bound vehicles”.
In addition to providing the AC voltage (e.g., 3 AC 400 V 50 Hz) required for the vehicle power system, auxiliary converters also deliver the required battery voltage (e.g., 110 V DC). To achieve this, they convert the DC voltage provided at the converter input. They ensure that train passengers can charge laptops and smartphones and the air conditioning and ventilation systems are running. Albrecht Neumann, CEO of Rolling Stock at Siemens Mobility: “Energy-efficient on-board train power systems can make a major contribution to economical and environmentally-friendly train operations.”
Without the converters, connectivity, information or entertainment services on trains would not be available. As part of the system, SiC reduces the overall costs in the on-board electrical system and the energy consumption of the auxiliary converter. It also enables more compact and lighter converter designs, along with a modular and service-friendly design to ensure lower maintenance costs.
The auxiliary converter makes use of power semiconductors in a half-bridge topology that are based on Infineon’s CoolSiC™ MOSFET 1200 V technology. Depending on the design, 8 to 16 half-bridge modules are installed for each converter.