What materials and architectures are used in the new technology of automotive drive motors?
Under the dual-carbon strategic layout, as the core component of new energy vehicles, drive motors need to pay more attention to the development of high efficiency, miniaturization and intelligence. In recent years, in order to further improve the core indicators of drive motors such as power density and efficiency and reduce costs, motor companies have continuously developed high-performance motor products, and key materials such as low/no heavy rare earth permanent magnets, 6.5% Si high silicon steel, soft magnetic composite materials, amorphous/nanocrystalline alloys have received much attention. In addition, although centralized drive is the current mainstream, distributed drive technologies such as wheel-side motors and hub motors have always been a research hotspot due to their advantages such as short transmission paths and independent control of torque between shafts 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 hub drives, still have problems such as poor controllability, high costs, and low reliability. Further verification is needed to promote their application in more models.
The following is mainly from the two dimensions of advanced materials for drive motors and distributed drives.
1. Advanced materials for drive motors
The 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, high-temperature resistant low-heavy rare earth/no heavy rare earth permanent magnets, high conductivity, low-loss super copper wires, and corona-resistant, high thermal conductivity insulation systems.
New soft magnetic materials include 6.5%Si high silicon steel, amorphous/nanocrystalline alloys, and soft magnetic composite materials. 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, thin, brittle, hard materials, and difficult processing, and are more suitable for ultra-high-speed and high-frequency motors.
Neodymium iron boron materials are still the most important rare earth permanent magnet materials. The permanent magnet MQ3 material using Nd-Fe-B rapid quenching thermal deformation technology is one of the key concerns of new permanent magnet materials. Reducing the amount of heavy rare earth is the current key research and development direction, and grain refinement technology, intercrystalline technology, intercrystalline diffusion technology, and comprehensive technology are the key research areas. In addition, the electromagnetic motor does not require the use of permanent magnets, which is also one of the industry's concerns and potential product options.
2. Distributed drive
Distributed drive is an important choice for the future development of electrification, and it empowers autonomous driving. Distributed drive includes key technologies such as torque distribution and control, drive anti-slip control, fault-tolerant control, and functional safety. At the same time, since distributed drive still has certain challenges in terms of controllability and cost, it may be first applied in high-end passenger cars and special vehicles (high performance requirements and insensitive to cost).
Wheel-side motors and hub motors are two important technical routes for distributed drive. Wheel-side motors can give full play to the electromechanical, thermal, and magnetic multi-field design advantages of deeply integrated electric drive assemblies to achieve small and lightweight drive motor and reducer assembly systems. Compared with hub motors, wheel-side motor engineering design is less difficult, but there are still cost challenges.
The wheel hub motor faces multi-dimensional technical challenges such as heat dissipation, sealing, control, and impact resistance. There is still a long way to go for large-scale mass production and application in the field of passenger cars. It is necessary to make breakthroughs in engineering design and verification such as efficient thermal conductivity and cooling technology, dust and water resistance, low dynamic resistance sealing technology, and integrated corner module technology.
Ningbo NIDE Tech Co., Ltd, adhering to the customer-centric concept, focuses on the stator, rotor and complete assembly of various motors, and provides customers with one-stop solutions for highly automated, intelligent and flexible production.
We independently develop and manufacture automotive flat wire hairpin motor manufacturing lines, EV drive motor production lines, new energy vehicle motor assembly lines, etc., providing customized automotive motor manufacturing solutions for global customers. We have mature hairpin coil forming technology, flux motor winding technology, needle winding machine technology, motor winding technology, etc., to meet customers' various motor winding technology needs, and provide complete motor manufacturing solutions and motor parts, one-stop solution to customers' motor manufacturing needs.