the italian supplier Marelli has presented in Dritev a new platform made up of silicon carbide inverters for the power electronics of electric vehicles operating under circuits of 800 volts. With these two technologies, Marelli has reduced its size and weight and, above all, has increased its efficiencya critical parameter for the case of electric vehicles.
The platform was presented for the first time at the International VDI Congress “Dritev” (Drivetrain Transmission Electrification in Vehicles), held in Baden Baden, Germany, between July 6 and 7, 2022, where Marelli also exhibited other electrification technologies.
Thanks to its excellent performance at high temperatures and voltages, silicon carbide (SiC) is recognized as a very suitable technology for power electronics. That is why it is particularly suitable for use in inverters. These are responsible for transforming the alternating current that feeds the synchronous electric motors from the direct current of the battery. The frequency of the alternating current determines the speed at which the motor rotates. This device uses high-level power electronics, capable of providing the voltage and amperage required by the motor at all times. The more robust the inverter, the more efficient and reliable an electric vehicle will be.
In addition to this, Marelli’s new inverter platform works integrated in 800-volt electrical circuits. By raising the voltage, it is possible to increase the recharging power, thus demystifying one of the great handicaps that electric cars currently have to be a purchase option for users.
The new one Marelli 800 volt inverter platform It also features an optimized thermal structure, thanks to innovative structural and cooling channel designs that dramatically reduce thermal resistance between the SiC components themselves and the coolant. This is critical in high power applications, where heat rejection from the power module is significant.
The result of the union of these technologies is that the new inverters presented by Marelli can extract more energy from the battery with greater efficiency and ensure a significant increase in the autonomy of a vehicle. It also ensures faster loading times and better acceleration. Finally, a smaller, more efficient inverter allows for a reduction in battery size, providing cost, weight, and sustainability benefits.
Razvan Panati, director of the Marelli Power Electronics Division, states that the new inverter platform “based on our 800-volt silicon carbide power module technology allows it to serve applications where energy use is optimized performance is maximized and efficiency is improved.”
In addition to hardware, Marelli develops the software for all inverters in-house which is housed in an Electrical Control Unit located in the same box as the inverter. The software complies with AUTOSAR (AUTomotive Open System ARchitecture) standards and is specifically customized for diagnostic standards required by automobile manufacturers. The functional safety requirements comply with the ASIL D (Automotive Safety Integrity Level D) standard.
The new 800 Volt SiC platform completes the range of inverters that Marelli has developed over the last ten years and which also includes 400 volt solutions based on both IGBT (Insulated Gate Bipolar Transistor) and Silicon Carbide, as well as Gallium Nitride (GaN).
The Marelli Group was created in 2019 as a result of the merger between the Italian supplier Magneti-Marelli (formerly owned by Fiat-Chrysler) and the Japanese firm Calsonic Kansei (which has its roots in Nissan). At the end of November 2020, the company announced its intention to assemble electric drives in Cologne, Germany, starting in 2021. To this end, an 18,000-square-meter production line was set up in the Cologne-Niehl district, not far of the German Ford plants.