Electronically commutated motor design

摘要

An electronically commutated motor has at least three rotor position sensors generating digital signals. To each commutating state of the motor is assigned a given combination of signals. These signals all form a first batch. Auxiliary information is given at the rotor by the same sensors to generate speed signals and these form a second batch of combinations. The rotor position information is given as a magnetising pattern and the sensors are galvano-magnetic types in order to detect this pattern. The auxiliary information coincides with the central region of each rotor pole, this being less than 60 electrical degrees, and during a pole rotation of about 20 electrical degrees.