There are various names on the market for brushless DC motors. They are known as, among other things, BLDC motors (brushless DC-motors) or EC motors (electronically commutated). An EC motor is structured like a three-phase synchronous machine with excitation through permanent magnets. Due to the brushless design, this type of motor is used primarily in applications with long service life.
Unlike a brushed DC motor – also called a DC motor – an EC motor requires additional electronics for detecting the current rotor position and for generating the necessary rotating field. Depending on the field of application, a distinction is made in the electronics between speed controllers (2-quadrant operation) and motion controllers (4-quadrant operation).
EC motors are available in a wide range of designs. In addition to the internal rotor motors, there are also external rotor motors and flat rotor motors. The winding is usually designed as a three-phase system and, depending on the speed range, with low to very high number of poles. Another version that should be mentioned here are motors with integrated electronics that are specially matched to the motor and expand the application spectrum yet further.