The global shift towards electric vehicles (EVs) is not just a matter of replacing petrol with batteries. At the core of this transformation lies a revolution in power electronics with SiC emerging as the enabler. SiC is fast replacing traditional silicon in key EV components, which otherwise suffer sharper drawbacks when it comes to efficiency, performance, and reliability
Silicon Carbide is a compound semiconductor material with a very wide bandgap, high thermal conductivity, and able to operate at higher voltages and temperatures than conventional silicon. Special, intrinsic properties of SiC find critical suitability in the harsh environment of EVs, where efficiency, weight reduction, and reliability constitute the high priorities.
Today, SiC enters major EV areas, such as:
- Inverters: Conversion of DC from the battery to AC for the motor (propulsion).
- DC-DC Converters: Step-down high-voltage battery power for auxiliary systems.
- On-Board Chargers: Controlling the charging process from external sources.
- Megawatt Charging System (MCS): Connecting to high-power lines for faster charging.
Key Benefits
- Operating with Higher Efficiency: Reduced switching and conduction losses in SiC devices mean less energy wasted as heat. This also means a greater driving range and better energy utilisation.
- Compact and Lightweight: The enhanced qualities of SiC allow for smaller, lightweight components, freeing space and adding to the reduction in vehicle weight.
- Thermal Performance: Being good in heat dissipation, SiC requires less bulky cooling systems and can pave the way for reliable operation at elevated temperatures.
- Faster Charging: Since SiC-based chargers can be run more efficiently at high voltages, they can support faster charging of EV batteries.
- Lower Cost Charging Stations: Integrated solid-state transformers utilizing high-voltage SiC devices (≥ 3.3 kV) reduce MCS cost, weight, and size.
SiC’s Impact on EV-Performance;
| Metric |
SiC vs Silicon Performance |
| Inverter Efficiency |
SiC: up to 99.1% vs Silicon: 97.1% |
| Range Increase |
5% to 10% more range with SiC |
| Power Loss Reduction |
Inverters up to 40% lighter, 30% smaller |
| Weight and Size |
Inverters up to 40% lighter, 30% smaller |
| Charging Time |
SiC enables 800V (and higher) systems, halving charge time |
| Battery Cost Savings |
SiC inverter can reduce battery size for same range, saving up to 5 per vehicle |
Major car makers are making use of SiC in their newest EVs. In the case of Audi, the use of SiC inverters has enhanced efficiency by nearly 60per cent under certain operating conditions. The 800V battery probably would not have come onstage if SiC had not been there, and it is now gaining traction in high-performance models from Kia, Hyundai, and Lucid, offering really fast charging and extended range.
Additionally, the electrification of heavy-duty vehicles, such as buses, construction equipment and tractors, is also a significant and growing trend. These heavy-duty EVs are bigger and heavier than passenger EVs and require higher-power levels for propulsion and charging. To address these higher-power requirements, the adoption of higher battery voltages, particularly around 1500V, combined with higher-voltage SiC technology, plays a crucial role in enabling the electrification of heavy- duty vehicles.
The increased efficiency of SiC-based systems results in less energy elimination and extends the range of EVs; and, therefore, reduces its overall impact on the environment. Small batteries equate to lighter vehicles that will consume fewer resources and emit fewer emissions during its lifespan. The other side of the coin is better reliability and durability that ultimately result in reduced maintenance and lower cost of ownership.
Silicon carbide is no ordinary material technology; rather, it is becoming a truly defining factor for the new generation of EVs, fast charging infrastructure, and electrified transportation overall, such as eVTOL (Electric Vertical Take-Off and Landing) aircraft. By giving rise to greater efficiencies, longer ranges, shorter charge times, and smaller sizes, Sic directly addresses some of the greatest impediments to mass EV acceptance. With ongoing R&D, the role of SiC in shaping and enabling the future of sustainable mobility will get stronger; empower energy to do more.
Article link:
https://auto.economictimes.indiatimes.com/news/auto-technology/silicon-carbide-the-game-changer-for-electric-vehicles/122548715