Advantages and disadvantages of brushless DC motors

Brushless motor includes motor body and drive, which is a typical mechatronic product.

Advantages of brushless DC motors:

1. With excellent linear mechanical characteristics of DC motors, wide speed range, stepless speed regulation can be realized, and the speed range is wide;

2. Excellent torque characteristics, good medium and low speed torque characteristics, large starting torque and small starting current; strong overload capacity;

3. Soft start and soft stop, good braking characteristics, can save the original mechanical braking or electromagnetic braking device;

4, high efficiency, brushless DC motors have no excitation loss compared to AC motors, compared to brushed DC motors, there is no brush friction loss and no sparks;

5, high reliability, good stability, strong adaptability, simple maintenance;

6, small size, light weight, high output;

7, resistance to bumps and vibrations, low noise, small vibration, smooth operation, long life.

Disadvantages of brushless DC motors:

1. Cost: Rare-earth permanent magnets are much more expensive than other permanent magnets, which leads to an increase in motor costs.

2. Limited constant power range: A large constant power range is critical to achieving high vehicle efficiency. It is impossible for a permanent magnet brushless DC motor to achieve a maximum speed greater than twice the base speed.

3. Safety: During the manufacturing process of the motor, it may be dangerous because the large rare earth permanent magnets can attract scattered metal objects. In the event of a vehicle crash, if the wheels spin freely and the motor is still excited by permanent magnets, high voltages will appear at the motor terminals, which may endanger passengers or rescuers.

4. Magnet demagnetization: The permanent magnet can be demagnetized by large reverse magnetomotive force and high temperature. The critical demagnetization force is different for each permanent magnet material. Care must be taken when cooling the motor, especially if the motor is compact.

5. High-speed performance: Surface-mounted motors of permanent magnets cannot achieve high speeds because this is limited by the mechanical strength of the assembly between the rotor yoke and the permanent magnets.

Shenzhen Motorplus Electric Co., Ltd. Widely used in automotive electronics, medical equipment, audiovisual equipment, information and communication equipment, household appliances, aviation models, power tools, massage health equipment, electric toothbrushes, electric shavers, eyebrow trimmers, hair dryers, camcorders, security equipment, Various electric products such as precision instruments and electric toys