Brushless DC Motor Design – What All You Need to Know

Traditionally seen as the high end of DC motor types, brushless DC motors (BLDCs) have typically been reserved for systems with high performance or efficiency requirements. However, motor-drive systems have become more integrated and control solutions become more readily available, system designers are finding it simpler than ever to move forward with BLDC motor solutions in order to reap the performance and efficiency benefits. To support this trend, you need quality development tools to help you rapidly get your BLDC motor spinning while minimizing development cost.

There are many different types of electric motors used in motion control. The design of the motor significantly impacts performance in terms of power, size and energy consumption. To understand if a brushless motor is right for your application, it’s important to first have basic knowledge of how a brushless motor works.

What makes a brushless motor different than a brushed motor? How many types of brushless motors are there in motion control? How do you choose the right one?

Brushless Motor Design vs Brushed Motor Design

As brushed motor depends on a mechanical system to transfer currents in order to create motion in the rotor. In these motors, a wound armature is attached at the center and a permanent magnet surrounds the rotor. The current is passed through to the armature coils, creating motion, when the brushes come into contact with a commutator.

Brushless motors, mainly AC induction motors and brushless DC motors, use an electronic mechanism to control current. No physical contact needs to be made in order to transfer current in a brushless motor, often making them a more energy-efficient option.

Brushless Motor Designs: AC Induction Motor vs Brushless DC Motor

In an AC motor, electromagnets surround the stator and produce a rotating current when power is applied. This causes the rotor to turn in response to the induction of a rotating magnetic field in the stator.

In a DC motor, permanent magnets are located on the rotor itself, instead of on the stator. Motion is created when current passes through the stator and the permanent magnets rotate based on the electromagnetic poles created by the stator.

AC motor design and DC motor design are quite different, but both produce a more efficient and durable solution when compared to brushed motors.

Brushless motor performance varies widely based on design. Understanding brushless motor designis the first step in finding the motor you need.