Brushless DC Motor: Also known as BLDC motor, it is a motor without brushes and commutator. The stator current is adjusted according to the position of the rotor permanent magnets to produce torque. Although it is called a “DC” motor, it is actually a permanent magnet synchronous motor (PMSM) that uses three-phase electricity.
It is called a “brushless DC motor” because it can replace a brushed DC motor in many applications. Therefore, BLDC motors are also called EC (electronically commutated) motors to distinguish them from mechanically commutated motors that contain brushes.
The BLDC motor uses power electronics technology to input control signals to the motor to switch the DC current switch and the passing coil group to obtain torque to rotate the rotor. But there are no restrictions on the waveforms of these control signals. The square wave drive is called BLDC and is used in situations where the position requirements are not very high; the sine wave drive is called PMSM and is used in servo situations.
Many products in real life use DC brushless hub motors, such as: electric scooters, electric bicycles, electric trolleys, electric wheelbarrow, robots, electric carrying-cart, mountain bikes, golf carts, etc.
So what is the advantages of brushless motor compare to brushed motor?
1. Low noise
Brushless motors have no brushes, so the friction during operation is greatly reduced, the operation is smooth, and the noise is much lower. This advantage is a huge support for operational stability. In addition, brushless motors are an advantage not only in the field of wheels, but also in many other fields. Home appliances, industrial automation, medical industries, etc. all require a silent environment.
2. Low interference and no sparks
The brushless motor removes the brush, and the direct change is that there is no spark generated when the brushed motor is running, which greatly reduces the interference of sparks to remote control radio equipment.
3. Low maintenance cost
Without the brushes, from a mechanical point of view, the brushless motor is almost a maintenance-free motor. When necessary, you only need to do some dust removal maintenance. Because it replaces the commutator and carbon brushes with a controller. The life of the carbon brush has a certain limit. For example, the carbon brush will wear out after a thousand hours and the brush must be replaced.
4. Long service life
The structural characteristics of the brushless hub motor determines that its service life is very long. Within a reasonable range of use, the brushless motor basically does not require additional maintenance costs, which also determines that its service life can be relatively long.
5. Good control effect
The brushless motor is equipped with a controller, which can realize control from simple to complex, and can realize various communication requirements, so that in addition to meeting some conventional mechanical actions, it can also execute complex control commands. And with the widespread use of magnetic encoders in recent years, they can replace some simple servo applications.
6. The motor is small in size
The permanent magnets of DC brushless hub motors are now mostly made of rare earth neodymium iron boron materials with high magnetic energy product. Therefore, the volume of the permanent magnet brushless hub motor is smaller than that of the three-phase asynchronous motor of the same capacity.
7. High motor efficiency
The brushless DC motor has high efficiency, large efficient area, high power and torque density, power factor close to 1, and system efficiency >90%. The rotor of the permanent magnet DC brushless motor operates synchronously under any circumstances. AC variable frequency motor It is variable frequency speed regulation. The brushless DC motor is variable frequency speed regulation. The motor runs at synchronous speed, and the rotor has neither copper loss nor iron loss.
8. Strong overload capability
The brushless wheel hub motor has strong overload capacity to meet the vehicle’s sudden stall needs. The regenerative braking effect is good. When the car is going downhill or braking, the motor can completely enter the generator state to charge the battery and act as an electric brake at the same time, reducing the burden of mechanical braking. The motor is small in size, light in weight and has high specific power, which can effectively reduce weight and save space.
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