Periodic Intermittent Duty: The class of duty making use of the ability of electric motors to operate with overload is called Periodic Intermittent Duty. The load on the motor is a sequence of identical duty…
Short Time Intermittent Duty: Another class of duty for normally occurring loads is Short Time Intermittent Duty in which the load requires a constant power for a short interval of time and rests for sufficiently…
Continuous Duty Motor: There are two types of Continuous Duty Motor — continuous duty at constant load and continuous duty with variable load cycle. In the former the load torque remains constant for a sufficiently longer…
Electric Motor Cooling and Heating: The geometry of an Electric Motor Cooling is too complex to predict accurately the heat flow and temperature distribution. This is a difficult task. A portion of the conductors of…
Electric Motor Power Loss and Heating: An Electric Motor Power Loss and Heating occurring in its various parts such as copper losses occurring in armature and field and eddy currents in the magnetic material used…
Reversible Drives using Choppers: Using two quadrant choppers a reversible drive can be achieved, because this combination allows reversal of both current and voltage of the motor terminals. We can get a regenerative reversible drive.…
Reversible Drive using Field Reversal: A Reversible Drive using Field Reversal can be realised as shown in Figs. 4.83 and 4.84. In Fig. 4.83, the armature is fed from a two quadrant converter with change…
Reversible Drive using Dual Converter: It is possible to reverse both voltage and current of the load using a dual converter. The current reversal is very fast in this case as the system is static…
Reversible Drive using Armature Current Reversal: A schematic of a reversible drive using contactors to reverse the Armature Current Reversal for reversing the rotation is shown kin Fig. 4.81. The contactors F1 and F2 are provided…
Reversible Drives using Phase Controlled Converters: When speed control in both forward and reverse directions is required a Reversible Drives is used. In several applications the speed reversal may be required very frequently in which…
