Can brushless DC motors be driven without a driver?

Can brushless DC motors be driven without a driver?

At present, many manufacturers of automation equipment are paying attention to brushless DC motors and prefer to use them instead of motors that have many insurmountable defects such as low efficiency and high noise, such as three-phase asynchronous motors and stepper motors. But during their consultation with Tengchi Motor Company regarding various parameters and technical issues of brushless DC motors, they mentioned that brushless DC motors do not require drivers? In fact, brushless DC motors cannot be driven without a driver. This is determined by the principle of brushless motors.

Brushless DC motors (BLDC) replace mechanical commutators with electronic commutators, and because of electronic commutation, brushless DC motors require driver circuits. The commutation circuit of a brushless DC motor consists of two parts: drive and control, which are not easily separated, especially for low-power circuits where they are often integrated into a single dedicated integrated circuit.

In high-power brushless DC motors, the drive circuit and control circuit can be integrated separately. The driving circuit outputs electrical power, drives the armature winding of the motor, and is controlled by the control circuit. The driving circuit has shifted from a linear amplification state to a pulse width modulation switching state, and the corresponding circuit composition has also shifted from transistor discrete circuits to modular integrated circuits. Modular integrated circuits are composed of power bipolar transistors, power field-effect transistors, and isolated gate field-effect bipolar transistors. Although the isolation gate field-effect bipolar transistor is relatively expensive, it is still a suitable choice from the perspectives of reliability, safety, and performance.

The driving methods of brushless DC motors can be classified into multiple types according to different categories, each with its own characteristics. According to the driving waveform: square wave driving, this driving method is convenient to implement and easy to achieve sensorless control of the motor; Sine drive, this driving method can improve the operation effect of the motor and make the output torque uniform, but the implementation process is relatively complex. At the same time, there are two methods for this method: SPWM and SVPWM (Space Vector PWM), with SVPWM performing better than SPWM.

Brushless DC motor (BLDC) replaces mechanical commutator with electronic commutator, so it not only has the good speed regulation performance of DC motor, but also has the advantages of simple structure, no commutation spark, reliable operation and easy maintenance of AC motor. This is also the reason why more and more automation equipment manufacturers love to use it,