New changes in the automotive industry, 48V automotive power supply will become mainstream

The new 48V power transmission technology is expected to bring major changes to the automotive industry due to the advantages of hybrid electric power and reduced complexity. Several automotive component suppliers in the industry are accelerating the adoption of 48V architectures for automotive internal power supplies. This vehicle power technology, called 48V, combines the advantages of dual voltage settings and 'start-stop' technology, which can more efficiently capture the braking energy of the car, which is more and more needed in the car. Multiple electronic loads provide more power while improving fuel efficiency, even up to 15%.

"We believe that within the next decade, 48V technology will develop into an important market," said Craig Rigby, vice president of product management strategy at Johnson Controls, which has developed 48V products. After the technology is popularized in the next generation technology of mass market consumers. "

The main demand of the 48V architecture comes from the micro hybrid power system (Micro Hybrid). In response to this demand, the United States Johnson Controls has developed a 48V voltage lithium-ion rechargeable battery module with a dual-voltage architecture, which includes a 12V low-voltage lead-acid battery and a 48V lithium-ion battery unit. The system can improve fuel economy by 15%. Infineon Technologies of Germany has created a motor control system that can support 48V voltage through its high voltage motor driver IC.

Emerging automotive transmission systems must support various energy storage technologies.

Audi in Germany said at the AABC held this year that the company and BMW, Daimler (Daimler AG) and Porsche and other automotive companies have decided to switch from 12V system to 48V system. This is because the traditional 12V system using lead-acid batteries does not support current values ​​above 100A, but in the future, in-vehicle electronic systems must be able to achieve an output power of up to 3kW. Therefore, Audi has planned to install a 48V lithium ion rechargeable battery module in addition to the original 12V engine, and connect the 48V lithium ion rechargeable battery module through a DC-DC converter, which is expected to enable the car to support a current of up to 130A.

American ConTInenTIal plans to standardize 48V lithium ion rechargeable battery modules. The company and battery manufacturer SK InnovaTIon jointly established a joint venture company SK ConTInental E-motion in January this year, and developed a 10Ah battery module.

A123 Systems is also committed to developing 48V lithium ion rechargeable battery modules. The use of lithium ion rechargeable battery modules of more than 100V can greatly improve the fuel efficiency of HEV, but the cost of special components and pressure-resistant components is high. The 48V lithium ion rechargeable battery module can not only improve the efficiency of 10 to 15% and has a high cost performance.

NXP Semiconductors uses its FlexRay transceiver series to support the automotive industry in adopting a 48V supply voltage in future models. NXP's new 48V FlexRay power supply system not only enhances the original 48V CAN transceiver series, but also withstands voltage performance up to +/- 60V.

NXP developed a 60V FlexRay transceiver to support the automotive industry's transition to 48V.

(Source: NXP Semiconductors)

In the late 1990s, the top executives in the automotive industry were talking about a technology called 42V. However, after several years of controversy, 42V has come to an end. However, the supplier said that the new 48V technology is very different from the 42V technology, and it provides a big leap forward in fuel economy. Furthermore, today's regulatory environment has changed, and battery technology has also advanced significantly.

The 48V technology supported by many automotive electronics suppliers in the industry requires that traditional 12V networks must use lead-acid batteries used in most vehicles. However, it also adds an additional layer: 48V lithium-ion battery and a separate 48V network. The 12V network handles traditional loads, such as lighting, ignition, entertainment, audio systems, and electronic modules. The 48V system supports active chassis systems, air-conditioning compressors, and regenerative braking systems.

One of the keys to the 48V specification is the lithium-ion battery technology, which is an advantage that the fateful 42V system could not have. Industry engineers believe that lithium-ion battery technology can provide three times higher energy density than lead-acid chemical batteries. In addition, "the use of lithium-ion batteries can also bring benefits in terms of size and weight," Rigby said. "As early as the 1990s, we have been looking for the voltage that can be achieved by combining three lead-acid batteries."

More importantly, the 48V lithium-ion battery has better charging performance, making it the best alternative technology for capturing regenerative braking kinetic energy. "It really can be attributed to the concept of a regenerative braking system-collecting kinetic energy from the deceleration of the vehicle and storing it in the battery."

Of course, traditional full-hybrid vehicles also provide the same function, but they usually use very high-voltage electrical architecture and high-voltage batteries. A few years ago, Toyota ’s Prius used a 500V power architecture, while the Ford Escape Hybrid used a 330V system, and the Lexus hybrid SUV was available. These voltages enable hybrid vehicles to support electrical loads of up to 20 kilowatts (kW), compared to 1.5kW for conventional 12V gas vehicles. As a result, they tend to easily respond to additional electrical loads and features, such as front seat heating, heatable windshields, rear shock absorbers, and ultimately electronic air conditioning, active chassis, and line drive systems.

Nevertheless, compared to the 12V system using traditional lead-acid batteries, the 48V architecture will provide more energy. "It even has the potential to increase to 10, 11, or even 12kW," Rigby said.

Industry suppliers regard the 48V power supply architecture as a reinforcement technology of the 'start-stop' system, and in fact it brings a greater reinforcement effect. The 12V 'start-stop' system may improve fuel efficiency by 5%, but the 48V 'start-stop' system provides an advantage of 15%.

If the growth rate of the 'start-stop' system can be used as an indicator, then 48V will also have the opportunity to be widely adopted. In Europe, about 50% of cars born this year will be incorporated into the 'start-stop' system, and this number is still rising. Rigby said that 48V is expected to bring the same appeal to consumers, however, "This technology will eventually return to the question of economic benefits-how much does it cost? What return can it bring? Fuel prices? These questions The answer will determine how quickly this 48V technology can be adopted. "