EMF and Torque Equation of DC Machine: EMF and Torque Equation of DC Machine – It was shown in Sec. 5.2 (Fig. 5.14 (a)) that in a dc machine the magnetic structure is such that the flux density wave in the air-gap is flat-topped with quarter-wave symmetry so long as the armature is not carrying […]
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Introduction of DC Motor: Introduction of DC Motor is constructed in many forms and for a variety of purposes, from the 3-mm stepper drawing a few μA at 1.5 V in a quartz crystal watch to the giant 75000-kW or more rolling mill motor. It is a highly versatile and flexible machine. It can satisfy
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Construction and Working Principle of DC Motor: Construction and Working Principle of DC Motor is a heteropolar structure with stationary poles and the rotating armature (Fig. 5.8). DC Machine Basic Structure: An alternating emf of the same wave shape as that of B-wave is induced in every coil. As the armature rotates, the emf s
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Tooth Ripple in Armature Winding: Because of lower reluctance of the magnetic path corresponding to the teeth as compared to the slots, the flux density wave in the air-gap is Tooth Ripple in Armature Winding as shown in Fig. 6.9. Unlike the space harmonics of the B-wave which move at the same peripheral speed as
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AC Winding: Ac winding are generally of a 3-phase kind because of the inherent advantages of a 3-phase machine. The armature coils must be connected to yield balanced (equal in magnitude and successive phase difference of 2π/3 rad) 3-phase emfs. To begin with the slots around the armature periphery must be divided into phase-bands. Phase
Types of Armature Winding in Electric Machine: We Know that field and Armature Winding Machine are the essential features of electric machines. The field windings are simple arrangements with concentrated coils (i.e coils in which all the turns have the same magnetic axis). Types of Armature Winding Machine on the other hand comprise a set
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Electric Motor Characteristics: The machine and the load are the two components of an electro-mechanical energy-conversion system, and the Electric Motor Characteristics, generally, play a predominant part in the operating behavior of the complete system. In choosing an electric motor its speed-torque characteristic is needed to be known to a fair degree of accuracy and
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Synchronous Generator Ratings and Loss Dissipation: The Synchronous Generator Ratings and Loss Dissipation is its operating voltage, frequency, speed and kVA/MVA output at a specified power factor. In case of motors the output rating is given in kW (older practice was to specify the rated output in horse-power (1 hp = 746 W)). The dc
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DC Motor Losses and Efficiency: The Losses and Efficiency of a transformer have been studied in earlier lesson. As in the case of transformers, it is more accurate to determine the DC Motor Losses and Efficiency rather than by the direct load test in which the input and output are required to be measured. Furthermore,
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Types of Magnetic Leakage Flux in Induction Motor: The Magnetic Leakage Flux in Induction Motor is that flux which links only the stator or only the rotor windings. Because of the presence of air-gap in the magnetic circuit of machines, the leakage in these is quite significant and cannot be neglected in analysis as could
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