Electronically commutated motor
An electronically commutated motor is a synchronous motor that can be excited as a direct current motor via inverter electronics. It is also known as an EC motor or, as it does not have brushes like conventional direct current motors, which cause high-frequency interference in the supply mains, a BLDC motor (“brushless direct current”). PM motor (“permanent magnet”) is a further designation and refers to the fact that the rotor is a permanent magnet. The stator comprises several magnet coils and has a three-phase design. Commutation is effected electronically via the three coil strands and a bridge circuit.
The rotational speed of EC motors can be easily changed, making them ideal for controlling the speed of centrifugal pumps. They also have high output per size and very good efficiency, and exhibit no slip or heat build-up.