In general terms, induction motors with solid-steel secondary have higher secondary resistance than those containing high-conductivity material. Consequently, their torque/speed or force/speed characteristics are different to those of conventional induction motors. Thus, they produce high force at standstill and the force reduces with increase in speed. Their force-speed curve is then stable over the full range of motoring speeds. Starting current is relatively low and the entrefer is small, compared with linear motors with conducting-plate secondary, so magnetising current is reduced. The power factor is also higher, except at low slips. In addition, steel secondaries are robust, rigid and have good thermal properties. For motors designed for continuous high-speed operation, efficiency and power factor should be high. On the other hand, for low speed or standstill operation, attention should be directed towards other measures of performance such as the ratios force/input power, force/stator copper loss and force/weight.
Linear induction motors with solid-steel secondary
Linear-Asynchronmotor mit Kurzstator und Massivstahl-Laeufer zum Antrieb eines bewegten Ziels
Proc. Int. Conf. on Electrical Machines, Part 2 ; Sep ; 563-565
1984
3 Seiten, 7 Bilder, 3 Quellen
Conference paper
English
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