China's new energy vehicle industry is booming.
Recently, as the electric vehicles of geely automobile, zhongtong bus and other well-known domestic automobile enterprises rolled off the production line, the high-performance permanent magnet motors of new energy vehicles led by jingjin best electric (Shanghai) co., LTD. (hereinafter referred to as jingjin electric) have been installed in over 70,000 units.
From the first-generation round wire winding motor with a power density of 4.2-5.3kw /kg to the second-generation flat copper wire winding motor with a power density of 6.3kw /kg, the product and sample indexes of permanent magnet motor are equal to or better than the product level of first-line automobile motor manufacturers in Europe, America, Japan and South Korea.
In the past two years, the company and 17 other units in the national "13th five-year" key research and development plan of new energy vehicle drive motor special, drive the upstream industry chain to break the technical bottleneck, fill a number of national technology and product gaps.Among them, the use of heavy rare earths in high-end rare earth permanent magnets has been reduced by nearly 50%.The insulation material's long-term temperature resistance exceeds 200℃, and the corona life of the round electromagnetic wire reaches several times of the national standard.The corona-proof life of enamelled flat wire is more than 90 hours......
Some of the raw materials, core components and components that used to be imported have been independently developed and produced. Some of the materials not only have a service life of twice that of foreign countries, but also cost only 60% of that of foreign countries.
As of June 30, 2019, the first generation of circular winding motor of the project has been loaded with 68,000 passenger cars and nearly 4,000 commercial vehicles.
Drive motor is comparable to the world's leading automotive motor manufacturers.
The development of new energy vehicles is inseparable from the core components of electric drive - motor system.High speed, high efficiency and high reliability of the motor, can make the new energy electric vehicle energy consumption lower, longer life.
The current of the motor is conducted by the windings, and insulation is required between the windings and between the windings and the core.Low resistance and reliable insulation are the basic requirements of motor winding.
In the early 21st century, CAI wei, a well-known motor expert, invented the "hairpin winding" motor, which was later applied to the general motors Chevrolet Tahoe hybrid car. This is the world's first application of the "hairpin winding" motor in the field of automobile electric drive.
Since the launch of the national key research and development plan in 2017, CAI wei, as the special leader, led jingjin electric and other units to complete the technical innovation, mass production and loading application of the first generation of circular winding motor with power density of 4.2kw /kg.
At the same time, the second generation of flat electromagnetic wire winding motor has also completed the sample manufacturing and performance testing, entered the test certification link.Through clever design, they can solve the problem of multiple parallel branch wave winding configuration topology, adjust cooling and welding parameters, conquer many BoBian line motor winding manufacturing difficulty, logarithmic and improves the motor rotation speed, the motor made smaller and copper wire, the material such as silicon steel sheet with less, less unit power supplies, higher cost performance.
"The power density increased from 4.3kw /kg to 6.3kw /kg, exceeding the 4.6kw /kg power density of Bolt motor and 3.8kw /kg power density of BMW i3 motor and exceeding the target of 5.7kw /kg power density of new energy vehicle motor planned by the us in 2025.Cai Wei said.
On this basis, the third generation transposition conductor winding motor has also been started research and development.
High-end permanent magnet weight rare earth consumption fell by 50%.
In the global new energy vehicle electric drive, the permanent magnet motor accounted for nearly 90%.Adding dysprosium, terbium and other heavy rare earths into permanent magnets can maintain remanence and improve coercivity."However, the reserves of heavy rare earths in rare earth mines are small, and with the popularization of new energy electric vehicles and mass production of rare earth permanent magnet motors at home and abroad, the use of heavy rare earths will face a resource shortage bottleneck."Some developed countries have used low-weight rare earth permanent magnets in motor products, Mr. CAI said.
China accounts for more than 90 percent of the world's supply of rare earths with 23 percent, according to a white paper titled "China's rare earth status and policies."
But China's rare-earth permanent magnet system and permanent magnet motor have long been subject to Japan."Japan used to buy China's rare earth permanent magnet raw materials, make them into permanent magnets and even motors, and then sell them to us at a high price or export them to Europe and the United States."Cai Wei said.
How to use heavy rare earth resources efficiently to avoid resource shortage and reduce cost?In the national special project, CAI wei led and cooperated with yantai shougang magnetic materials co., LTD., to research and develop drip technology and lattice refining technology to reduce the use of heavy rare earths by up to 50%.
"In the past, heavy rare earths such as dysprosium or terbium were often rolled together like dough with other raw materials for permanent magnets.Now by refining the lattice, the heavy rare earths are infiltrated into the magnets, where they need to go, in small but precise quantities."
CAI wei introduced that the research and development personnel filled the gap of fine powder technology in China with the process of grain refinement and microstructure consistency, and the dysprosium content of 35EH magnets was reduced from 7wt% - 8wt% to 5wt% in mass production, reducing the use of heavy rare earths by more than 20%.At the same time, they combined the fine powder process with the diffusion process to reduce the terbium content of 42EH magnets from 8wt% to equivalent dysprosium 4.5%, reducing the use of heavy rare earths by 40-50%.
Part of the insulation corona-resistant life up to 10 times the national standard.
As the heart of new energy vehicles, there are a lot of electromagnetic lines in the drive motor.If the electromagnetic wire and insulation materials can not withstand the high voltage, high temperature, high voltage change rate in the motor operation, it is easy to be broken down, reduce the service life of the motor.
However, the corona-resistant insulating materials produced in China basically come from foreign manufacturers, "such as the raw materials such as nano-particle modified polyesters and imines and corona-resistant soft composite paper, which may suffer from neck jam at any time.CAI wei says, the strength of seller market, let domestic user helpless.
In the project, joint Cai Wei suzhou giant peak insulation materials co., LTD. (hereinafter referred to as the giant peak), the use of nano particles and enameled wire paint resin composite technology, break through the nanoparticles in the wire coating resin difficult dispersion technology bottleneck, evenly dispersed nano dispersion was prepared, the successful preparation of corona resistant enameled wire paint.
At present, the corona resistant polyester imine impregnated resin developed by jufeng has a long-term service temperature of more than 200℃.The corona-resistant enamelled flat wire developed by the company has a test life of more than 90 hours, which fills the gap in China and exceeds the target of international competitors.Corona resistance enamelled round wire corona resistance life more than 100 hours, up to 10 times of the national standard requirements.
In September this year, the CPC Central Committee and the State Council issued the outline of building a strong transport country, strengthening research and development of cutting-edge key technologies and aiming at the new generation of information technology, artificial intelligence, intelligent manufacturing, new materials, new energy and other cutting-edge technologies in the world.
In CAI wei's opinion, the automobile industry is the top priority of highway traffic.
Contact: GUOKONG ELECTRIC
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