Here are key areas where semiconductors can have the most impact in EVs, specifically in relation to the car’s battery, and how vendors are enabling faster development of EV systems.
The electric vehicle (EV) market has reached an inflection point, transitioning from a niche low-volume sector to a high-volume mass market. Right now, supply is constrained, and car makers can sell every EV they make, but this is only a temporary situation.
In this article, we’ll look at a few of the key areas where semiconductors can have the most impact in EVs, specifically in relation to the car’s battery, and how vendors are enabling faster development of EV systems.
EV MARKET TRENDS
The EV market is gradually taking off, driven by a combination of legislation, government tax breaks, and popularity with consumers. A recent Gartner forecast estimates 6 million electric cars will be shipped in 2022, up from 4.5 million in 2021, and this figure will reach 36 million cars by 2030.
Legislation is pushing car makers towards electrifying their entire fleet. For example, in the European Union, cars and vans sold from 2035 onwards must be zero emission, with interim targets to reduce CO₂ emissions (compared to 2021 levels) by 15% in 2025 and 55% by 2030. In China, which is the largest market for EVs, similar mandates require electric cars to make up 40% of all sales by 2030.
For car makers, there is no time to waste. They must ready themselves for high-volume production of EVs, without compromising quality. They also need to avoid the kind of supply chain disruption seen recently in the automotive industry and ensure they have enough batteries and electronics to meet sales targets.
Car makers also need to continue to improve their EVs, to tempt new buyers away from conventional vehicles, as well as compete with new disruptive car makers entering the market.
BATTERIES GET SMART
Two of the most important competitive factors for an EV are the range the car can drive between charges, and how long the recharging process takes. Being able to get more miles without having to stop is a major differentiator, and if that charging stop can be made as quick as possible, then drivers are happy.
Both range and charging time relate specifically to the car’s battery, and the battery management system (BMS) around it. In fact, the battery is the most expensive part of the EV and the component that gives the most scope for differentiation.
The range of a car can be increased by simply giving it a bigger battery, but this substantially increases the overall vehicle cost, as well as adds to the weight of the vehicle and takes up more space.
Instead, one could make better use of the existing battery by fully understanding its limits. A cloud-connected smart battery is a concept that holds great promise. A digital twin model of the battery is built in the cloud, which combines physical, machine learning, and AI algorithms using data not just of a single car, but the entire fleet.
The concept of a connected battery and data collection is not new. The type of data you collect, how you go about collecting it, and what you do with the data, however, offers a lot of potential for innovation and differentiation.
The advantages of such a smart battery include being able to improve range prediction and therefore the efficiency of the battery, as well as increasing battery longevity. It can enable faster charging—a major differentiator—and can assess the residual value of the battery, as well as help reduce overall costs of ownership.
Being able to model battery behavior enables car makers to predict a battery’s state of health and state of charge. The data from smart batteries can also be used for optimizing battery lifetime by recommending charging and driving strategies, predictive maintenance, and spotting likely problems before they happen—thus increasing reliability and safety.
To create the smart battery, semiconductor vendors are the enablers, providing chipsets for data acquisition, communication, and processing. The data acquisition in the car should be based on precise, safe, and reliable local sensing capabilities, as well as flexible and secure connectivity to the cloud.
The data collected must be accurate, relevant, and acquired to match the requirements of the battery models, the battery system data refresh rate, as well as meet the highest functional safety standards, even in very harsh electromagnetic and environmental conditions.
But to use the smart battery’s full potential, close collaboration of all players is needed in the value chain: car makers, system integrators and Tier 1s, battery makers, software and services providers, and the semiconductor vendors.
Together, an efficient ecosystem can be established to reduce time to market and ensure interoperability. With strong partnerships in place, we can encourage service providers to create new use cases and applications.
But what about the charging infrastructure and the BMS electronics in the vehicle that facilitate fast charging?
There are multiple factors to consider when designing charging systems, such as speed. But OEMs also need to consider safety, security, reliability, and accurate measurement of power delivery.
Everything needs to be coordinated so the driver is presented with a simple system that gives them the confidence to use it. Interoperability is another moving target—how can we ensure drivers can use chargers from multiple providers and can be billed straightforwardly and transparently?
Today’s DC fast chargers typically take somewhere between 30 to 45 minutes to charge the battery to 80%. That’s acceptable, but still too slow for drivers in a hurry. Increasing the speed of charging raises difficult technical challenges, including the high currents involved in generating heat due to the charging cable’s internal resistance.
A promising approach is to increase the EV’s system voltage from 400 V, which is most common today, to 800 V. With double the battery voltage, charging can theoretically be achieved twice as fast, perhaps in as little as 15 minutes, and cables can be kept to a manageable size and weight. By 2025, 800 V is expected to be the mainstream technology in the EV market; with faster charging, consumers may potentially accept cars with less range.
Moving to 800 V does create its own problems, however. The higher voltage brings with it more potential for damaging electrical arcs, so isolation requirements are stricter. Also, components in the car’s traction inverter must be rated for 800 V.
Compared to 400 V architecture, an 800 V BMS needs to monitor twice as many battery cells with the same performance, but with increasing electromagnetic compatibility challenges. Overall, all these changes add to the system cost—faster charging comes at a price.
With so much change occurring over the next few years, the speed of innovation is vital for car makers. The automotive industry has traditionally had long design cycles and has been slower to adopt new technologies compared to the consumer sector. That is a luxury that EV makers cannot enjoy anymore—to stay competitive, they must cut time to market and find ways to accelerate product development.
Some companies have already shown that they will soon be able to bring a new design from idea to production in just 12 months, and this kind of compressed development cycle will only become more common.
Responding to this challenge, we are seeing changes in how car makers approach design and production, with many manufacturers adopting a modular approach, such as VW’s MEB (modular electric drive matrix) platform helping to reduce costs and accelerate development. VW has adopted NXP’s BMS into the MEB platform to increase vehicle range, extend battery longevity, and enhance safety.
Regardless of the drivetrain power source, there is an increasing amount of electronics in today’s cars. There is a shift away from a vehicle defined by its hardware to one where software sets its capabilities and performance (see “Software-defined vehicles drive next-gen connected EV development”).
Semiconductor vendors need to change from providing just components to offering complete system solutions with pre-validated hardware and software. These solutions should handle the low-level software and middleware of the connected car, enabling car makers to focus on adding value with higher-level software, as well as making it easier to re-use software across multiple models.
Working together, semiconductor vendors and their ecosystem partners can create the solutions that car makers and Tier 1s are looking for—making the electrification of vehicles a positive change for consumers. Not only can semiconductor vendors provide solutions that deliver environmental improvements, but they can also ensure cars are safer, more efficient, and simply better to drive.
This article was originally published on EE Times.