Introduction of permanent magnet brushless motor
(3) In the electric vehicle field, the use of drive motors. In 2004, China produced a total of 6,576,100 electric bicycles, an increase of 69.05% over the same period of last year. Most of its drive motors use brushed DC motors, but due to the inherent shortcomings of DC brush motors, short life. Maintenance is difficult. As the price of permanent magnet brushless DC motor decreases, the reliability of the controller increases, and more and more permanent magnet brushless motors are used. Energy is tight, environmental pollution is increasing, electric vehicles show strong vitality, and are favored by automobile manufacturers and consumers. According to statistics, by 2010, electric vehicles will account for a quarter of the global demand for automobiles, and the total amount will reach 20 million vehicles, such as the US General Motors, Japan Toyota, and France Citroen, all take electric vehicles as their development direction. China also attaches great importance to it. It has been listed by the Ministry of Science and Technology as a major national key project during the 10th Five-Year Plan period. It is also the 11th Five-Year Plan. One of the important aspects of developing green transportation in planning. Electric vehicle drive motors have brush DC motors, variable frequency asynchronous motors and permanent magnet brushless motors, but the trend is permanent magnet brushless motors, especially Japanese automakers use permanent magnet brushless motors. The driving motor in the electric power steering system of the automobile has a brush DC motor and a permanent magnet brushless motor, but the trend is also a permanent magnet brushless motor. It is a trend to replace the brushed DC motor with a permanent magnet brushless motor for motors used in important systems such as safety in electric vehicles. The permanent magnet of the motor adopts sintered NdFeB. The winding forms include two types: concentrated winding and distributed winding. The motor structure has two kinds of outer rotor and inner rotor. As for the general motor used in automobiles, it is still dominated by brushed DC motors, and the micro-motors for automatic vehicles account for about 17% of the entire micro-motors.
(4) After adopting the permanent magnet brushless synchronous motor servo control system, the elevator not only has small volume, energy saving, good control performance, but also easy to realize deceleration direct drive to eliminate the gear reduction device, which is superior to low noise, leveling accuracy and comfort. Previous brushed DC motor speed control and asynchronous motor frequency control. It is suitable for use in machine roomless elevators, so the permanent magnet brushless synchronous motor drive is favored by major elevator companies.
