Brushless Motor is a synchronous motor, that is to say, the rotational speed of the motor rotor is affected by the speed of the stator rotating magnetic field and the rotor pole number. Brushless Motor has the advantages of traditional DC motor, while eliminating the carbon brush, slip ring structure, stepless speed Regulation, wide speed range, strong overload, high reliability, good stability, strong adaptability, simple maintenance and maintenance. The commutation circuit of Brushless Motor consists of drive and control parts, which are not easy to separate, especially the small power circuits tend to integrate the two into a single ASIC.
The DC motor has the capability of providing rated torque with fast response, large starting torque, from zero speed to rated speed. But the advantages of DC motor is its disadvantage, because the DC motor to produce a rated load on the performance of the constant torque, then the armature magnetic field and the rotor magnetic field must maintain 90°, this will be through the carbon brush and rectifier. The carbon brushes and the commutator will produce sparks and toner when the motor rotates, so that in addition to the damage to the components, the use situation is limited.
Brushless Motor is composed of motor body and actuator, and the stator windings of the motor are made of three relative star-shaped methods, which are similar to three-phase asynchronous motors. The rotor of the motor has a magnetic permanent magnet, in order to detect the polarity of the motor rotor, a position sensor is arranged inside the motor. The actuator consists of a power electronic device and an integrated circuit, the function is: to accept the start, stop and brake signals of the motor to control the start-up, stop and braking of the motor, and to accept the position sensor signal and the positive and negative signal to control the on-off of each power pipe of the inverter bridge, to generate the continuous torque; accept the speed command and the speed feedback signal Used to control and adjust the speed, provide protection and display and so on.
Brushless Motor consists of motor main body and actuator, it is a typical electromechanical integration product. Since the Brushless Motor is operated by automatic control, it will not be like the synchronous motor of the heavy-duty start-up under the variable frequency speed regulation, but also the starting winding on the rotor, and it will not generate oscillation and loss step when the load is mutated. Medium and small capacity Brushless Motor, the permanent magnet, now uses the high magnetic energy level of rare earth NdFeB (-) material. Therefore, the volume of the rare earth Permanent magnet brushless motor reduces the size of the same-capacity three-phase asynchronous motor.
In simple terms, the alternating frequency and waveform of the current wave on the stator coil of the brushless motor are changed by the the windings around the winding coil form a magnetic field rotating around the axis of the motor, which drives the permanent magnet magnets on the rotor, the motor turns up, the performance of the motor and the number of magnets, the magnetic flux strength of the magnet, Motor input voltage size and other factors, more with brushless motor control performance has a great relationship, because the input is DC, the current needs electronic governor to turn it into 3-phase AC, but also need to receive control signals from the remote receiver, control the speed of the motor to meet the needs of model use. In general, the structure of brushless motor is relatively simple, the real decision to use the performance of the brushless electronic governor, good electronic governor need to have Single-chip control program design, circuit design, complex processing process, such as the overall controls, so the price than the brush motor is much higher.