What is BLDC motor? Know the difference between a brushless and brush DC motor

Brushless DC electric motors (BLDC motors or BL motors), also known as electronically commutated motors (ECM or EC motors) and synchronous DC motors, are synchronous motors that are driven by direct current (DC) electricity via an inverter or switching power supply that generates alternating current (AC) to drive each step of the motor through a closed-loop controller. Continue reading the article to know how does BLDC motor work.

What is BLDC Motor or Brushless DC Electric Motor?

Brushless motors have a higher power-weight ratio, higher rpm, electronic control, and they require less maintenance as compared to brushed motors. Brushless motors are used in a number of applications which include computer peripherals, handheld power tools, and vehicles ranging from model planes to automobiles. Brushless DC motors have allowed direct-drive designs to replace rubber belts and gearboxes in modern washing machines.

With brushed motors, the brushes are the ones that deliver current through the commutator into the coils on the rotor. In the case of Brushless DC motors, they do not make use of brushes and therefore the current is not delivered through these brushes. The coils aren't on the rotor at all. Instead, the rotor is a permanent magnet, and the coils are set in position on the stator rather than rotating. Brushes and a commutator are unnecessary since the coils do not turn.

Rotation is done with the brushed motor by regulating the magnetic fields produced by the coils on the rotor, while the magnetic field generated by the stationary magnets remains unchanged. The voltage for the coils is changed to adjust the rotation speed. The permanent magnet rotates in a BLDC motor, which is accomplished by adjusting the direction of the magnetic fields produced by the surrounding stationary coils. You change the magnitude and direction of the current into these coils to regulate the rotation.

Advantages

• One significant benefit is performance, as these motors can control at full rotational force continuously (torque).
• Controllability is the second major benefit, which is linked to the first. BLDC motors can be programmed to deliver precise torque and rotation speed using feedback mechanisms. Precision control, in turn, decreases energy consumption and heat generation, while also extending the battery life in cases where motors are powered by batteries.
• Due to the lack of brushes, BLDC motors are also very durable and produce very little electric noise.