The demand for sustainable transportation is increasing immensely, leading experts to predict electric vehicle sales will exceed 10 million units by 2025. In recent years, we’ve seen an increase in EV options because of decreasing battery prices and consumer desire for more sustainable transportation.
To make certain these pure-electric and hybrid-electric vehicles are safe, reliable and perform efficiently, advanced electronically controlled systems must work together across a wide range of operating conditions.
Here are the top five challenges the broader industry and designers must overcome as hybrids and EVs become more popular:
- Charging Infrastructure: While there has been an increase in charging infrastructure such as the daily charging stations in commercial parking areas, outside company buildings, and garages, the biggest issue for consumers is the availability of charging stations for long-distance travel. There are simply not enough charging stations for those traveling to destinations much farther from home than the local grocery store and work. To keep up with the fast-paced growth of hybrid and electric vehicles, large investments will be needed to expand charging infrastructure. Fortunately, the federal Inflation Reduction Act of 2022 was recently signed into law, providing billions to accelerate the production of EVs and charging infrastructure. Additionally, many U.S. consumers will be able to use the light-duty EV tax credit of up to $7,500 per vehicle through 2032.
- Less Efficient Batteries and Restricted Driving Range: The lithium-ion batteries for vehicle electrification currently provide drivers a range of 249 to 311 miles (400 to 500 km); this is considered a limited driving range because drivers expect a range of more than 400 miles (644 km). Battery design is limited by the power density related to the mass and size of the pack. Increasing the mass negatively affects the vehicle’s braking, handling and acceleration, and requires more energy. In addition, designers must make certain the batteries do not degrade too much over time so drivers won’t need to replace their vehicle battery multiple times over the lifespan of the car.
- EV Reliability: Power components such as motor, battery and power electronics are vulnerable to environmental stress including mechanical shocks and temperature variation, making powertrain reliability a key challenge for designers. How the performance of one component might impact another needs to be considered by multiple parties.
Another obstacle is the ability of the microcontroller to optimize power efficiency for a different component of the EV as long-term design flexibility is dependent on high- to low-end designs. Due to strict temperature specifications, on-chip memory solutions must comply with the AEC-Q100 standard. Additionally, designers using 7nm and 10nm parts are seeing integration challenges that haven’t been debugged yet, on top of existing systemic defects.
- Power Semiconductors: EVs are reliant on power conversion systems. Power conversion systems that use silicon-based power semiconductor switches increase efficiency and minimize energy loss . However, silicon power semiconductors like MOSFETs have limited voltage. Insulated-gate bipolar transistors (IGBT) are power semiconductors that can operate between 400V to 1600V but cannot be used in high-frequency operations. To overcome these barriers, wide-bandgap devices such as silicon carbide (SiC) and gallium nitride (GaN) can be employed because they are small, can function in high-voltage and high-frequency modes, and are able to operate with high thermal conductivity and less on-state resistance. However, they are expensive and few manufacturers produce them.
- Fluctuating Automotive Supply Chain: Compared to a gasoline-powered vehicle, an electric drivetrain has about 3,800 fewer parts. Benefits of this include lower cost, less maintenance and overall reduced cost of ownership. However, because suppliers are very reliant on OEMs and the simulation tools they use, integration is more vital than ever. OEMs and suppliers must proactively update their supply chains if they are to keep up with future mass EV adoption based on global incentives and future restrictions. For example, China began requiring 10% of new-car sales to be fully electric or hybrid in 2019 and Europe has a goal to ban fossil fuel-powered vehicles by 2040.
The Key to EV Growth
Design teams need a cost-effective design solution to meet safety, reliability and performance specifications demanded by consumers and the industry. A systematic development approach, known as robust design, has been created to meet these demands.
Methodologies of robust designs are put in place to optimize and manage complex system interactions, benefiting the designs of hybrid and electric vehicles. Design teams will need to integrate a robust design flow with a comprehensive simulation solution to efficiently verify and analyze the complex EV drivetrain systems across a wide range of conditions. Collaboration among design teams, along with robust design tools, can go a long way toward ensuring EVs are safe, reliable and exceed performance expectations.
Datsen Davies Tharakan (pictured, left) is senior applications engineer, Synopsys Systems Design Group.