Just like internal combustible engines, the power source for alternative energy-powered vehicles must be managed to optimize safety and reliability through delivery.
That goes for solar vehicles.
Solar electric vehicles (SEV) require battery management systems (BMS) and switching systems similar to those associated with electric vehicles (EVs), hybrid-electric vehicles (HEVs), and other electrified systems. Solar vehicles are in the conversation because, although EVs and HEVs are wedging their way into the mainstream of automotive technology, it's not without driver anxiety related to battery recharging and range issues.
Automotive engineers believe solar power might be the solution. Solar-powered vehicles run longer on the same battery.
But where are we on solar-powered vehicles and the management of power going into solar-power applications?
Solar vehicles have been in development for years. In Fort Worth, Texas, we've all seen video clips of the Solar Car Challenge at Texas Motor Speedway or similar competitions. On a consumer scale, several automotive startups and established EV makers, such as Tesla and Toyota, are developing solar cars or hybrid versions of them, but none are yet available to the buying public. Aptera recently announced the third and final Alpha version of its upcoming SEV, with production and delivery targeted for 2022. Tesla's Cybertruck, also due in 2022, will have an add-on solar panel option that will allow the vehicle to charge from the sun while driving or parking. Both the Aptera and Cybertruck have unorthodox vehicle chassis designs, which are intended to harvest solar energy. In 2020, Hyundai Motor. Co. unveiled a hybrid version of its Sonata model equipped with a roof-mounted system. The model consists of a solar panel and controller that enable the vehicle to generate and store electricity in a battery.
The current design of solar road vehicles looks mostly like solar panels on wheels. In effect, they're EVs covered with photovoltaic cells integrated as panels that can recharge without stopping. Developers are working on projects involving solar-panel integration into roofs and hoods for passenger cars, including efficient connection to the vehicle's power management system. Something has to regulate and monitor this energy.
In this week's New Tech Tuesdays, we look at vehicle electrification products from Littelfuse and Analog Devices.
Design engineers can use Littelfuse DCN High-Current, High-Voltage DC Contactor Relays to incorporate high-voltage relay switching into a range of high-current and high-voltage applications. Applications include EVs, charging stations for EVs and HEVs, and electric forklifts. But high-voltage connections and relays are also used for solar-energy power regulation, switching the outputs from photovoltaic panels. Littelfuse's relays provide from 30A to 500A continuous carry and up to 1800V voltage rating. Designers will appreciate the DCN series being available in side or bottom mount relays with no restrictions on the mounting orientation.
The Analog Devices Inc. LTC2949 Current and Stack Voltage Monitor IC measures current, voltage, temperature, charge, and energy for EVs and HEVs, and other isolated current-sense applications to enable a reliable BMS. By measuring key parameters, designers have the essentials to calculate the real-time state of charge (SOC) and state of health (SOH) for the entire battery stack. This continuous integration of current and power ensures lossless tracking of charge and energy delivered or received by the battery pack and keeps the wheels turning. The LTC2949 easily addresses multiple stack monitoring topologies and configurations. The device has a 1 percent energy and charge accuracy, is designed for ISO26262 compliant systems, and is AEC-Q100 qualified for use in automotive applications, all of which are crucial for next-generation EV BMS.
Solar vehicles require the same battery management systems and relay switching capabilities as other alt-energy projects. BMS is a critical part of any rechargeable battery-powered system and careful consideration must be given to the design and selection of components. As solar vehicles advance in the development stages and become available on the market, design engineers should find more electrification products for alt-energy solutions.
Tommy Cummings is a freelance writer/editor based in Texas. He's had a journalism career that has spanned more than 40 years. He contributes to Texas Monthly and Oklahoma Today magazines. He's also worked at The Dallas Morning News, Fort Worth Star-Telegram, San Francisco Chronicle, and others. Tommy covered the dot-com boom in Silicon Valley and has been a digital content and audience engagement editor at news outlets. Tommy worked at Mouser Electronics from 2018 to 2021 as a technical content and product content specialist.