Drive technology for AC and DC

VARIODRIVE CompactVARIODRIVEInformationMotor principlesThe ebm-papst EC range is based on two types of motor that have completelydifferent contruction features: on the one hand, the external rotormotors of the VARIODRIVE, VARIODRIVE Compact and VarioDrive C series;on the other, the internal rotor motors of the ECI, ECI Compact and BGseries.Each of these 6 series has an independent performance profile that is notonly underlined by highly sophisticated motor characteristics but is also ofeconomic significance. Detailed information can be found in the introductorypassages of the individual product groups.Another classifying feature for distinguishing between the internal andexternal rotor motor design is the basic structure of the winding and theactive motor parts. Here, it is primarily the number of grooves of the statorand the number of pole pairs of the magnet rotor that are of key significance.For the activation of the motors, we can make a basic distinction betweenthe simpler variant of block commutation and the more elaborate one withsinus commutation. For block commutation, the number of switching pulsesresults from the number of phases of the winding and the number ofpoles of the rotor. For sinus commutation, the commutation of the currentin all 3 winding phases is continuous. In this process, based on a continuoussine/cosine sensor signal, the 3 winding phases are energised by ahigh-frequency PWM modulation with sinusoidal phase-shifted currents foreach, which enables smoother running behaviour and lower speeds.The external rotor motorIn external rotor motors, the bell-shaped rotor isfirmly connected to the shaft and revolvesaround the stationary stator. The motor flange isextended axially to support the stator with windingsand the printed circuit board. Magneticfield sensors (Hall ICs) in the main field are usedto determine the rotor position. Compared to theinternal rotor motor, the magnets are fixed on agreater diameter providing not only a largermagnetic volume but also a concentration ofmagnetic flux to the stator inside. Furthermore,the same electromagnetic force and the greaterair gap diameter result in a higher torque.BCI motorBG motorECI motorVarioDrive CExternal rotor motorBall bearingsHall ICStatorRotor with motor shaftMagnet9Representatives Specifications AC motors