Under the dual-carbon strategic layout, the drive motor, as the core component of new energy vehicles, needs to pay more attention to the development of high efficiency, miniaturization and intelligence. In recent years, in order to further improve the power density, efficiency and other core indicators of drive motors and reduce costs, motor companies have continued to develop high-performance motor products, such as few/no heavy rare earth permanent magnets, 6.5% Si high silicon steel, soft magnetic composite materials, amorphous /Nanocrystalline alloys and other key materials have received much attention. In addition, although centralized drive is the current mainstream, distributed drive technologies such as wheel motors and hub motors have also been a hot research topic due to their short transmission paths and independent control of torque between axles or wheels.
However, the development of new drive motors also faces some problems. For example, some key materials of innovative drive motors still have pain points such as difficult processes and high costs. Distributed drives, especially wheel hub drives, still have problems such as poor controllability, high costs, and low reliability. Further verification is needed to promote application on more models.
The following mainly focuses on the two dimensions of advanced materials for drive motors and distributed drives.
Advanced materials for drive motors:
Key materials that affect the performance and cost of drive motors include permanent magnets, silicon steel sheets, copper wires, etc. In the future, it is necessary to focus on the development of high-strength, low-loss electrical steel and new soft magnetic materials, and high-temperature resistant low-heavy rare earth/no-heavy rare earth permanent magnets , high conductivity, low loss super copper wire and corona-resistant, high thermal conductivity insulation system, etc.
New soft magnetic materials include 6.5% Si high silicon steel, amorphous/nanocrystalline alloys, soft magnetic composite materials, etc. The manufacturing process of 6.5%Si high silicon steel is complex, resulting in difficult quality control, low production efficiency, and high cost; amorphous/nanocrystalline alloys have low saturation magnetic density, and the materials are thin, brittle, hard, and difficult to process, making them more suitable for ultra-high-speed and high-voltage applications. frequency motor.
NdFeB material is still the most important rare earth permanent magnet material, and MQ3 permanent magnet material using Nd-Fe-B fast quenching thermal deformation technology is one of the focuses of new permanent magnet materials. Reducing the consumption of heavy rare earths is the current key research and development direction, and grain refinement technology, intergranular technology, intergranular diffusion technology, and comprehensive technology are the focus of research. In addition, electric excitation motors do not require the use of permanent magnets and are also one of the industry's concerns and potential product options.
Distributed driver:
Distributed drive is an important choice in the future electrification development process, and it mutually empowers autonomous driving. Distributed drive includes key technologies such as torque distribution and control, drive anti-skid control, fault-tolerant control and functional safety. At the same time, because distributed drive still has certain challenges in terms of maneuverability and cost, it may be the first to be used in high-end passenger cars and special vehicles ( High performance requirements and not cost-sensitive) implementation of applications.
Wheel motors and hub motors are two important technical routes for distributed drive. The wheel motor can give full play to the electromechanical, thermal and magnetic multi-field design advantages of the deeply integrated electric drive assembly to achieve a smaller and lighter drive motor and reducer assembly system. Compared with in-wheel motors, the engineering design of wheel-side motors is less difficult, but there are still cost challenges.
In-wheel motors face multi-dimensional technical problems such as heat dissipation, sealing, control, and impact resistance. There is still a long way to go before large-scale mass production applications in the field of passenger cars. High-efficiency thermal conductivity and cooling and heat dissipation technologies are required, as well as dustproof and waterproof , low resistance dynamic sealing technology, integrated corner module technology and other engineering design and verification areas need key breakthroughs. Article source: Energy-saving and new energy vehicle technology road map.
