I started to plan my 2024 The trend of high-speed drive motors for new energy vehicles is clear, and at the same time, the centrifugal force on the rotor becomes greater due to high speed, which brings challenges to the stability and safety of the motor. In order to ensure the safe and stable operation of high-speed motors, permanent magnets need to be protected. Compared with the metal sheath, the carbon fiber composite sheath has the characteristics of light weight, high strength and durability, low electrical conductivity, high thermal conductivity, etc., which can play a protective role while reducing eddy current loss and will not affect the heat dissipation of the rotor, which can better match the high-speed needs of the motor, thereby improving the performance of the motor. In addition, the carbon fiber sheath can be used in parallel with the high-strength silicon steel sheet, which can be used together to help the rotor of high-speed motors overcome the challenges of high centrifugal force.
In terms of industrialization progress, Tesla pioneered the application of carbon fiber rotors, and used carbon fiber to wrap the rotor in the Model S Plaid delivered in June 2021 to strengthen its structural strength, with a maximum speed of 20,000 rpm+ and a maximum speed of 322 kilometers per hour. After that, a number of domestic and foreign OEMs and Tier1 closely followed.
Based on this, the design advantages of high-speed carbon fiber rotors are very obvious. In order to reduce the heat dissipation problem of the electric drive system, considering that the carbon fiber material will produce thermal expansion and contraction after heating, a certain distance gap should be reserved between the rotor and the stator, and if necessary, the surface of the carbon fiber rotor can be refined to ensure the necessary air gap; The high structural strength of carbon fiber can inhibit the metal thermal expansion of the rotor, so that the distance between the rotor and the stator can be reduced, thereby increasing the utilization rate of magnetic flux, and under the same input current, the speed of the electric drive system increases, the work becomes larger, and the efficiency is improved.
For the technical problems of improving the performance of the next-generation electric drive motor, the carbon fiber rotor can solve the rotor structure safety problem caused by high speed, and the shaft current problem generated by high voltage can be solved by carbon fiber brushes. In terms of cost, by increasing the investment in complete sets of equipment, the unit production cost can be reduced.
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Tesla Motors
Tesla Motors is the first in the industry to design a carbon fiber protective sleeve on the rotor of the electric drive system, the core role of which is to strengthen the structural strength of the rotor of the electric drive system, prevent the permanent magnet from falling off under high speed conditions, and at the same time can improve the leakage flux of the electric drive system and improve the lightweight of the electric drive system. The Plaid model of the Model S X is equipped with this technology, which can reach a top speed of 322 km h (three-motor four-wheel drive, single motor in the front and dual motor in the rear, and a maximum speed of 20,000 rpm).
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Zhixin Technology
Dongfeng Motor's new energy models are mainly equipped with the electric drive system designed and developed by Zhixin Technology, Dongfeng Motor's Dongfeng Mach e new energy power brand unveiled at the 2023 new energy power system brand spring conference, of which the Mach electric drive system has four highlights: "extreme integration, high efficiency and high speed, surging power, and intelligent control", and the electric drive system adopts carbon fiber coated rotor technology, with a speed of up to 30000r min, which matches the silicon carbide controller independently developed by Zhixin Technology. The maximum efficiency of the system can reach 945%, so as to achieve the purpose of "high speed and high efficiency".
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Hongqi New Energy
Hongqi Automobile's self-developed Hongqi HSM high-efficiency electric drive system, which is the world's leading ultra-light, high-magnetic-dense carbon fiber rotor, ultra-high frequency high-power silicon carbide module, active and passive noise suppression and other technologies, has achieved the world's leading 955% system efficiency and "zero" perceived noise. Among them, Hongqi's self-developed carbon fiber composite material wraps the rotor assembly, which uses the characteristics of extremely high tensile strength and low expansion coefficient of carbon fiber to firmly wrap the rotor core and magnet. The carbon fiber circumferential tension is wound around the surface of the rotor, which applies precise preload to the rotor of the electric drive system, so that the rotor assembly is fully protected and the electric drive system can achieve smooth operation.
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Weirui Electric
ZEEKR 001FR uses four 800V silicon carbide permanent magnet synchronous motors, all of which are self-developed by Geely's Weirui Company, and the rear electric drive system adopts two motors arranged in parallel, with a single output power of 310kW, a maximum speed of 20620rpm, and a power density of 44kw/kg。And in order to cope with such a high speed, the surface of the electric drive system uses self-developed carbon fiber coated rotor (to be exact, Huayu's carbon fiber material); The combined maximum horsepower of the system is 1,265 hp, of which the first two motors have an innovative asymmetrical parallel arrangement, and the output power of each is 155kW.
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BorgWarner
BorgWarner, as a TIRE1** supplier, launched a carbon fiber motor rotor with a maximum speed of 25,000 rpm at the Shanghai Auto Show in April 2023, helping to realize the product development and application of high-power, high-speed electric drive systems.
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Zhiji Automobile
The LS6 model released by Zhiji Automobile in 2023 adopts a stator and rotor dual oil cooling scheme for its electric drive system, of which the rotor also uses the electric drive technology of carbon fiber shell, and it is equipped with a new generation of electric drive system of SAIC Motor's carbon fiber rotor electric drive system 800V high-voltage electric drive "super combination, with a maximum speed of 21,000rpm and a speed of 252km h.
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GAC Aion
On March 3, 2023, GAC Aion unveiled a new generation of high-performance integrated electric drive: Quark Electric Drive.
GAC Aion's Quark motor combines its patented X-PIN flat wire stator technology and carbon fiber high-speed rotor technology, which can reduce the size of the electric drive system by 25% and increase the electric drive power by more than 30%. In addition, the X-PIN carbon fiber high-speed motor technology has 3 national patents for unique platform winding schemes, which can achieve multi-platform compatibility with 70kW 320kW power range and 220 450Nm torque range.
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Xiaomi car
Xiaomi Auto will release a new car in 2023, the SU7 electric drive system uses a number of eye-catching technologies. Following the successful mass production of the 21,000-rpm Xiaomi Super Motor V6 V6S and the 27,200-rpm Mi Super Motor V8S that will be mass-produced in 2025, Xiaomi Lab announced that it has completed the pre-research work of 35,000-rpm motor technology, which will undoubtedly enhance Xiaomi's leading position in the field of motor technology again.
In addition to the increase in speed, Xiaomi has also adopted a new carbon fiber Aurora winding rotor process in the research and development of new motors. This innovative process utilizes laser in-situ curing technology to achieve precise winding and curing of carbon fibers. Compared with the traditional rotor manufacturing process, the carbon fiber aurora winding rotor process has higher precision and better preload, which significantly improves the mechanical strength and wear resistance of the rotor. In addition, this process can effectively improve production yield, reduce manufacturing costs, and lay a solid foundation for the mass production and application of motors.
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Inovance United Power
It is understood that at present, Inovance United Power has achieved a number of breakthroughs in technology:
The maximum speed of the powertrain motor has reached 20,000rpm, which is higher than the mainstream 12,000-14,000rpm, and the technology development of the 25,000rpm carbon fiber rotor has been completed.
The first ultra-low welding process motor was successfully rolled off the assembly line, and the slot filling rate of the flat wire motor was greatly increased by more than 20%, and the power density of the motor was increased by more than 8%.
The second-generation SiC motor controller is on the market with the customer's model and is about to enter the stage of mass delivery (the company is one of the few third-party suppliers of SiC electronic control in China).
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Sky blue
At a forum, Sky Azure guests shared a case of 800V 20,000 rpm, the same size motor, the traditional scheme 1mm air gap, the new scheme 2mm gap, carbon fiber layer 12mm, the power is increased from 280kW to 314kW, the corresponding torque is increased by 16Nm, and the maximum efficiency is increased by 02%。
The company's carbon fiber rotors have the following advantages:
Process and equipment development capabilities: Customized and developed an industry-leading, high-precision tension control system for wet and dry carbon fiber composite material winding machine, and has the ability to independently develop equipment, which can be continuously iterated.
Perfect raw material testing equipment: with winding resin viscosity, gel time, thermogravimetric curve, glass transition temperature, thermal expansion coefficient of thermal expansion, carbon fiber mechanical properties, carbon fiber composite material mechanical properties and other related testing equipment.
Perfect carbon fiber rotor testing and reliability evaluation capabilities: with dynamic balance instrument, high temperature overspeed testing machine, high-precision CT scanner, three-coordinate size testing equipment, vacuum hydrocarbon cleaning machine and cleanliness analyzer, oil compatibility test tank, high temperature aging chamber, high and low temperature impact test chamber, high and low temperature cycle test chamber, constant temperature and humidity test chamber, mechanical shaking table and other full testing and reliability evaluation equipment.
Carbon fiber rotor acceptance standard: Based on the perfect equipment testing ability, a full range of testing and acceptance standards have been established from the aspects of raw materials, product performance, process condition parameter influence, product reliability evaluation, etc., to ensure high-quality and efficient product development, iteration and quality control system, so that customers can rest assured.
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Moson Technology
The founding team took the lead in starting the research and development work as early as 2017, and the company broke through the key technology - non-destructive winding under ultra-high tensile strength, and has a full range of technical capabilities from carbon fiber materials, structural design, electromagnetic design, molding and assembly process, equipment manufacturing and inspection and testing.
In terms of customers, at present, Moson Technology's carbon fiber rotor products have been purchased in bulk by Gree Equipment, Jiangte Motor, CLP 21 and other enterprises, and closely cooperate with more than 20 OEMs and Tier1 manufacturers to cooperate in the research and development of carbon fiber rotors for high-speed permanent magnet motors for new energy vehicles.