High-Density SiC and Si Inverter Stack Reference Models

Mersen will unveil two high power density dc-ac inverter stack reference models at the Applied Power Electronics Conference and Exhibition, booth 1303, March 27-29, in Tampa, FL. In addition to the stack reference models, Mersen will also highlight a full complement of products designed for electric vehicle and battery-related dc applications as well as offer two presentations during the Industrial and Exhibitor Presentation Sessions.

The stack reference models were assembled under the "Integrated Architecture" approach in close collaboration with partners Infineon, AgileSwitch, and FTCAP, and optimized by Mersen Cooling and Bus Bar engineering teams. This team has developed 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 PrimePACKâ„¢ 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.

The Silicon reference design is based upon three Infineon IGBT5 .XT FF1200R12IE5 modules driven by AgileSwitch PPEM series. This setup allows the 700Vdc / 850Arms converter operating at 8kHz and delivers up to 750kVA. The SiC reference design is built around a 3-phase, 700Vdc / 200Arms water-cooled converter, powered by three Wolfspeed CAS300M12BM2 modules pushed up to 20kHz 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 laminated busbars are designed by Mersen 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 degrees C. Peak efficiency exceeds 98% in both cases.

This integrated architecture approach allows inverter designers to save time and confusion in selecting individual components; designers 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.

While continuing to expand services to traditional market segments such as transportation, alternative energy, military, power conversion, and solutions for silicon-carbide (SiC) applications, Mersen will highlight dedicated solutions that focus on emerging markets such as electric vehicle and battery-related dc applications.

Over 50 different product samples will be on hand at booth # 1303 that illustrate the quality and range of technologies Mersen brings to their customers. From liquid cold plates to laminated bus bars to semiconductor protection and special purpose fuses, numerous samples will be available to view and handle.

Mersen has the honor of presenting at industrial session presentation ID 1003 during APEC show titled: "DC Protection for e-Mobility and Battery Related Systems." This presentation, given by Philippe Roussel, Ph.D. with Mersen, will discuss how DC- specific fuses as well as newly developed hybrid dc over-current protection systems can jointly offer a superior blanket of electrical protection for today's demanding EV and HEV DC applications, making them safer and more reliable. In addition, Mersen is presenting the topic of "Safety and Reliability for Power Electronics" during Exhibitor Presentation Sessions