
Mersen launches silicon and SiC power reference designs
The SiC reference demonstrator has been designed using Wolfspeed SiC modules with power density value of 16kW/l for SiC 150kVA heavy-duty Electric Vehicle (EV) inverter, exceeding the US Department of Energy (DoE) 2020 roadmap. The design is built around a 3-phase, 700 VDC / 200 ARMS water-cooled converter, powered by three Wolfspeed CAS300M12BM2 modules with 20 kHz switching using AgileSwitch’s 62EM1 Gate Driver with patented Augmented Switching and advanced fault monitoring.
The IGBT reference demonstrator has been designed for Electrical Energy Storage (EES) applications using three Infineon IGBT5 .XT FF1200R12IE5 modules driven by AgileSwitch PPEM series. This allows a 700VDC / 850 ARMS converter design operating at 8kHz that delivers up to 750 kVA at 25kW/L.
While the latest IGBT and SiC devices are a benefit for inverter or power stack designers who can increase the overall system efficiency, it brings some new challenges on the cooling, busbar, gate driver and capacitor sides. Essentially these surrounding devices define the overall inverter dimensions and ultimately the final power density value.
“Mersen, Infineon, AgileSwitch and FTCAP have gathered together the latest technical innovations that can be offered to our inverter manufacturer clients” said Dr Philippe Roussel, VP Strategic Marketing at Mersen, which is part of the French Carbon Lorraine group and was formerly known as Ferraz Shawmut.
The integrated architecture approach allows inverter designers to save time and confusion in selecting individual components and can greatly benefit from a solution that is optimally pre-designed for their specific application. Power modules, busbar, cooling, gate drivers and capacitors can now be optimally designed together in one step to answer electrical, mechanical and thermal challenges of the system.
For both designs, a custom DC-link capacitor bank (700V/3,500µF for IGBT and 1,000V/760µF for SiC) has been specifically developed by FTCAP to minimize the footprint and optimize the thermal transfer to the heat-sink underneath. High temperature, low inductance, AC and DC Mersen laminated busbars are designed to minimize skin-effect induced by ripple-current. Mersen high performance aluminum vacuum-brazed cold-plate can dissipate up to 10kW losses for IGBT and up to 3kW losses for SiC, keeping power module Tj below 130°C. Peak efficiency exceeds 98% in both cases
Reference designs can be supported by purchasing individual components and Mersen can also provide assembly services.
