The characteristic of brushless motors is that all motors that have the external characteristics of DC motors and use electronic commutation are collectively called brushless motors. Due to the emergence of brushless motors, the strict boundaries between AC and DC speed control systems have been broken. In the history of the development of brushless motors, there have been two different structural forms of brushless motors, namely brushless DC motors and AC commutated brushless motors.

The power of the brushless DC motor is ultimately supplied in the form of DC. According to the way of obtaining DC power, brushless DC motors usually have two main implementation methods: AC-DC-AC control system and DC-AC control system, which are commonly known as square waves.

The AC commutated brushless motor uses a thyristor inverter to directly convert 50Hz AC power into AC power whose frequency changes with the rotor to supply the motor. Its speed regulation characteristics are also similar to those of DC motors. At this time, the input of the motor is a positive linear wave.

In fact, the AC commutated brushless motor is much more complicated than the brushless DC motor. There are actually differences in the subsequent naming. The brushless DC motor has always used its original name, while the AC commutated brushless motor is called It is called a permanent magnet synchronous motor.

If the phase commutator is integrated inside the motor, it can still be called a DC motor if the input is DC, but high-power phase commutators are usually outside the motor, so the AC power supplied to the motor through the phase commutator is actually AC. The structure of the brushless DC motor is very similar to that of the permanent magnet synchronous AC motor. The difference is that the input of the brushless DC motor is a square wave, while the input of the permanent magnet synchronous motor is a sine wave.

Therefore, brushless motors have both DC and AC types, and you can choose according to your needs.