Sustainability in EV/HEV powertrains

Now more than ever before, the demand for energy-efficient vehicles is growing, posing new challenges and opportunities for engineers looking to design electric and hybrid electric vehicles. With new advances in Silicon Carbide (SiC) technology, it’s now possible to develop reliable, rugged inverters to power electric drivetrain without sacrificing efficiency or sustainability.

The Demand for EV/HEV Power Components

The demand for electric vehicles (EVs) and hybrid electrical vehicles (HEVs) is rapidly growing as more people take an interest in the environmental impact of their personal transportation. As EV/HEV designs continue to improve, it is crucial to have reliable and sustainable power components for several systems in a typical EV/HEV, including the drivetrain.

Challenges Related to Electric Drivetrains

The design and development of electric drivetrains for EVs and HEVs include several significant challenges: the components must be durable and extremely reliable, while still supporting sustainability. The rugged conditions they face typically involve extremely high temperatures, high voltages, and high humidity.

The inverter, tasked with converting DC power from a hybrid battery to AC power for the drivetrain, is just one key component in EV and HEV vehicles. For an EV/HEV to be truly sustainable, the power conversion process must be as efficient as possible.

SiC-based MOSFETs for Inverters

Traditional inverters are designed with silicon IGBTs, which are different than MOSFETs. We could say "EV inverters require power semiconductors with high voltage and current capabilities. Traditionally, these systems have been designed with silicon IGBTs, however Silicon carbide MOSFETs are outpacing them when it comes to the critical design requirements of modern electric drivetrains.

Silicon carbide is a wide bandgap technology, which means its inherent material properties enable it to safely operate at high voltages and extreme temperatures. SiC MOSFETs, therefore, are ideally suited to meet the system requirements of efficiency and robustness that modern drivetrain inverters demand. These advantages over traditional silicon technology enable extended driving range and ultimately a more sustainable EV.

650V SiC MOSFET Family

Wolfspeed's new 650V SiC MOSFET family enables power solutions that are highly efficient, power-dense, and run at very cool temperatures. When a power component runs cool, it supports the overall system efficiency and reduces component count since the additional cooling systems needed are either smaller or eliminated completely. Each of these features supports sustainability and makes an excellent case for their use in power inverters.

Wolfspeed and SiC MOSFETs

The continued evolution of the SiC MOSFET has made it possible for engineers to design powertrain inverters rugged enough to handle high-temperatures and extreme humidity, while providing higher voltage ranges and faster switching speeds compared to their Si counterparts. Wolfspeed has thirty years of experience in developing power solutions, including Silicon Carbide components that contribute to the design goals of EV/HEV and renewable energy. In fact, Wolfspeed is already on its third generation of SiC MOSFETs. When looking for reliable, sustainable power components and solutions for EV/HEV drivetrains, look to the experts at Wolfspeed for help.

Product and Reference Design Solutions

Reference Designs

Explore Wolfspeed’s 650V SiC MOSFETs, companion parts, and reference designs to learn more about how SiC MOSFET technology from Wolfspeed can help you build better products that are up for the demands of today’s modern devices.

Demonstration of Wolfspeed’s 650 V, 60 mΩ (C3M™) SiC MOSFETs in a 6.6 kW Bi-Directional converter targeting high efficiency and high power density On-Board Charging applications  The demo board consist of a Bi-Directional Totem-Pole PFC (AC/DC) stage and an Isolated Bi-Directional DC/DC stage based on a CLLC topology with a variable DC Link Voltage  Utilization of the high switching frequency operation allow the demo board to be smaller, lighter and overall more cost effective   Wolfspeed’s 6.6 kW High Power Density OBC demo board can accept 90VAC-265VAC as an input and provide 250VDC-450VDC at the output with > 96.5% of efficiency in both charging and inversion modes  Main target applications of this demo board include: EV Charging and Energy Storage  Documentation includes a bill of materials (BOM), schematic, board layout and the application note

Evaluate and optimize steady state and high speed switching performance of Wolfspeed C3M™ SiC MOSFETs and Schottky diodes  Analyze the evaluation board in versatile power conversion topologies, such as Synchronous / Asynchronous Buck or Boost converter, Half Bridge and Full Bridge (Please note: Full Bridge topology requires 2 Evaluation Kits)  Board features footprints for both 3 and 4 lead TO-247 packages of C3M™ SiC MOSFETs  Compatible with both TO-247 and TO-220 packages of SiC Schottky diodes  Does not require an additional capacitor to run the evaluation board in the buck or boost converter topologies  Two (2) dedicated gate drivers available on the board for each C3M™ SiC MOSFET  Includes (2) 1200 V, 75mΩ C3M™ SiC MOSFETs in a TO-247-4 Package with the testing hardware

Demonstration of Wolfspeed’s 650 V, 60 mΩ (C3M™) SiC MOSFETs in a 6.6 kW High Frequency DC-DC converter targeting high power density applications  The demo board consist of a DC-DC LLC topology in which primary side is based on a Full bridge stage while the secondary side is based on a asynchronous rectification stage  Utilization of high frequency operation allow the demo board to be smaller, lighter and overall more cost effective   Wolfspeed’s 6.6 kW high frequency demo board can accept 380 VDC – 420 VDC as an input and provide 400 VDC at the output with > 96 % efficiency  Main target application of this demo board include: Industrial power supplies and EV Chargers  Documentation includes a bill of materials (BOM), schematic, board layout and the application note

Highly efficient and low cost solution of 2.2 kW bridgeless totem-pole PFC topology based on Wolfspeed’s latest (C3M™) 650 V 60 mΩ SiC MOSFETs  Comfortably achieve Titanium standard by having > 98.5% efficiency while THD < 4% under all load conditions  Innovative resistor based current sensing solution  Distortion less inductor current at zero crossing during all load conditions  Reduced Bill of Material (BOM) by the use of general purpose diodes in place of low frequency switches  Main target applications of this demo board include: Server, Telecom and Industrial power supply units (PSU)  Documentation includes bill of materials (BOM), schematic, board layout, application note