Motor vehicle drive system requirements are higher performance, higher density, the volume-weight ratio, higher temperature tolerance range, and can withstand intense vibration and more low cost. To meet the more stringent requirements of even the harsh, automotive motor drive technology development tendency can be summarized as permanent magnet, digitalization and integration.
Electric vehicle motor drive system is different from the ordinary fans, pumps and other industrial applications. Vehicles used by the space constraints and environmental constraints, vehicle required motor drive system has a higher performance, higher density, the volume-weight ratio, higher tolerance to environmental temperature range (liquid cooling inlet temperature> 105 ), can withstand high intensity such as vibration and lower cost. To meet the more stringent requirements of even the harsh, automotive motor drive technology development tendency can be summarized as permanent magnet, digitalization and integration. Permanent magnet technology to provide efficient
Permanent magnet motor with high efficiency than power, power factor, high reliability and easy maintenance and so on, using vector-controlled frequency control system, permanent magnet motor can have a wide speed range, therefore, to Toyota Motor and Honda Motor as the representative of the international and domestic manufacturers of FAW, Dongfeng, Chang’an, Chery and other manufacturers are used in electric vehicles in its permanent magnet motor program, and promoted to the permanent magnet motor vehicle in the direction of development.
Permanent magnet motor main materials, components are neodymium iron boron magnets, electrical steel and high-speed bearings. Since entering the 21st century, our country more than 20% annual growth rate of magnetic materials industry. According to preliminary statistics, in 2004 reached 27,510 tons NdFeB permanent magnet (81% of global total), bonded NdFeB to 1350 tons (accounting for 35% of the global total). Materials for manufacturing motor cores, electrical steel is the most important magnetic materials in general, is highly efficient motor vehicles, the protection of high power density, the cost of accounting for the cost of the motor body 20%. It is reported that Japan’s Sumitomo Electric 0.27mm thick electrical steel production has been used in hybrid electric drive motor, the Baosteel Group of China "863" project support, carried out from 2008 electric vehicle drive motor with electric steel R & D, China vehicle drive motor system is expected in the near future efficient use of domestic electrical steel. In addition, to ensure that electric vehicles after 20 km and can withstand severe cold and heat is still running, motor vehicle still needs to invest in developing high-speed bearings, developed by our country the majority of motor drive system adopts imported high-speed bearings.
Is the trend of digital inverter
In electric vehicles, fuel cell or battery by a DC can be provided by one or more inverter to convert AC power-driven permanent magnet motor sports, including motor vehicle by the inverter and controller motor control circuit. So far, as most electric cars lower than the DC voltage 600V, three-phase inverter are used the two-level structure and 1200V IGBT modules under which the core device IGBT inverter and the capacitance of the costs account for motor control devices cost more than 50%. In hybrid electric vehicle applications, in order to simplify the cooling system to reduce vehicle costs, vehicle motor drive system is presented coolant inlet temperature higher than 105 the requirements of this request except to improve the electrical insulation and neodymium iron boron magnets grade, the market widely used IGBT junction temperature 150 can not meet the requirements, the need to use junction temperature of 175 IGBT, and careful design of high heat transfer efficiency of the radiator system.