Application of Brushless DC Motor in Automobile
Application of Brushless DC Motor in Automobile
Feb 27, 2019

Brushless DC motor without brushes and commutators, can solve the space constrained system design, and do not worry about general wear, sparks and noise, provide good control, provide variable speed control for specific applications in automobiles. Brushless DC motor can also improve fuel efficiency and save energy consumption. Brushless DC motor has the following applications in automobiles:

1. Vehicle purifier adopts brushless DC motor.

The automobile cleaner uses DC brushless motor to drive centrifugal blades to exhaust dirty air. The motor body is a commonly used two-phase bridge commutation drive circuit according to the motor circuit scheme. The stator winding can be conveniently wound around the core teeth. The motor is made of outer rotor structure, and stator and stator windings are placed inside the rotor. The commutation drive circuit adopts ASIC, which is simple in circuit and has control and protection function.

2. Brushless DC motor for automotive air conditioner

The development of brushless DC motor for low voltage and high current automotive air conditioning can solve the shortcomings of high noise, short life and difficult maintenance of the original brushless DC motor, and improve the electromechanical operation function. The rated voltage is 12V, which makes the design of brushless DC motor more difficult because of the limitation of structure. Stator punching sheet is 12-slot structure, because it is low voltage and high current type, in order to ensure the current density is not too high convergence, double-wire parallel winding is used to reduce the wire diameter; rotor is surface permanent magnet bonded 4-pole structure, permanent magnet is rare earth permanent magnet material Nd-Fe-B, because Nd-Fe-B remanence and coercivity are high, magnetizing direction. Therefore, the permanent magnet adopts radial tile type. The Holzer element is chosen as the position sensor. Installed in the inner surface of the motor end cover, the position sensor magnetic field is axial magnetic field.

3. Brushless DC motor for vehicle driving

At present, there are four types of motor used in vehicle driving: DC motor, AC motor, brushless DC motor, reluctance motor, etc. The practice shows that brushless DC motor has obvious advantages. The four wheels of the electric vehicle are directly driven by four independent wheeled motors. The inverter is used for electronic commutation and the mechanical commutator and brush are cancelled. This structure is convenient for high speed operation and does not affect the motor body when changing the tire. It is an advanced scheme in the world to adopt an external rotor motor which cancels gears and drives directly. However, the design of the external rotor motor is closely related to the design of the wheel structure of the vehicle. Therefore, in the case of less funds and less time, many manufacturers basically choose the internal rotor brushless DC motor. In addition, the disc permanent magnet brushless DC motor has large torque at low speed, and can win the front or rear wheels in electric vehicles, thus eliminating the mechanical transmission. The utility model has the advantages of compact axial structure, convenient installation, low noise, reliable operation and stepless speed regulation. The air gap magnetic field is axial, the stator winding is composed of radial conductors, the rotor is N and S alternately assembled in the disk yoke. The crux of this machine and electricity lies in the forming technique of the coil winding, which has complicated working procedure and long period. In order to improve the production efficiency, it is possible to change the epoxy resin used as insulation supplement material into thermosetting material and adopt heating molding technology.

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