Mersen beats next generation DOE power density targets through Stack Reference designs

June 8, 2017

Mersen, a global expert in electrical power and advanced materials, has teamed-up with AgileSwitch and FTCAP to develop two high performance 3-phase SiC and IGBT power stack 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 US Department of Energy (DoE) 2020 roadmap.

The IGBT reference demonstrator has been designed in the frame of Infineon Industrial Power Partner Network (IPPN), powered by IGBT5 with .XT technology from Infineon and targeted for Electrical Energy Storage (EES) applications. The Silicon IGBT5 .XT 500kVA demonstrator achieved 25kW/L.

New generation of power modules, such as Infineon PrimePACK™ IGBT5 with .XT or SiC MOSFET are exhibiting enhanced power density in the same footprint. Whereas this added-value is definitely a plus for inverter or power stack designers who can therefore increase the overall system efficiency, it brings some new challenges on the cooling, bus bar, 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,” stated Dr. Philippe Roussel, VP Strategic Marketing at Mersen. 

This 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, bus bar, cooling, gate drivers, and capacitors can now be optimally designed together in one step to answer electrical, mechanical, and thermal challenges of the system. Our philosophy being: “Design, driven by function not by component.“

The Silicon reference design is based upon three Infineon IGBT5 .XT FF1200R12IE5 modules driven by AgileSwitch PPEM series. This setup allows the 700VDC / 850 ARMS converter operating at 8kHz and delivers up to 750 kVA. The SiC reference design is built around a 3-phase, 700 VDC / 200 ARMS water-cooled converter, powered by three Wolfspeed CAS300M12BM2 modules pushed up to 20 kHz switching using AgileSwitch’s 62EM1 Gate Driver with patented Augmented Switching and advanced fault monitoring. 

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 additionally Mersen can provide assembly services. 

With industrial operations in all three major economic regions of the globe, we look forward to discussing your application and working together to design and develop your best solution for your power conversion application.