Practical Electric motor handbook pptx

[...]... be developed to produce the desired motor action In DC motors, armature reaction can twist the direction of the field flux and thereby reduce the available torque 20 Practical Electric Motor Handbook Small permanent magnet DC motor I I DC Voltmeter = Sw Fig 1.14 Simple demonstration of a basic operating feature of electric motors Switch, Sw, is closed, placing the motor in operation The voltmeter will... 1.12 yield the same answers when two motor 18 Practical Electric Motor Handbook Fig 1.12 Resolving the confusion with the motor "hand rules' Some texts relate motor operating parameters with the left hand while others depict the use of the right hand (a) The left-hand motor rule is valid for conventional current-flow (From "plus" to "minus'.) (b) The right-hand motor rule is valid for electron current-flow... To Electric motor generalities 15 C (a) (b) (c) I T (d) (e) Fig 1.10 Some symbology pertaining to electric motors can be confusing (a) This symbol was originally used for DC motors, but has become valid for other motors utilizing brush-commutator systems It can be confusing to use it for just any motor (b) This is a better symbol for AC motors as a class It also is preferable to (a) when depicting electric. .. series type, the wheels are driven by the electric motor The enginegenerator set can be used not only to charge the battery but, bypassing the battery it can power the electric motor In the parallel hybrid, the electric motor, the engine, or both can drive the wheels With the electric motor acting as a generator, the battery can be charged Inasmuch as the design of electric vehicles brings together the... Battery *-, motor Transmission @ lC,=c Selector Transmission (b) The two major formats for hybrid vehicles (a) The series hybrid: Only the electric motor drives the wheels The engine-generator combination can be used, however, to bypass the battery and directly power the electric motor (b) The parallel hybrid: The engine, the electric motor, or both may be used to drive the wheels The electric motor, acting... Moreover, the field-winding of 10 Practical Electric Motor Handbook Fig 1.8 Armatures of entirely different dynamos (a) The armature of a DC motor (Also similar to those used in AC repulsion motors.) (b) The armature of an AC three-phase induction motor Confusion can be avoided by referring to the stationary winding of AC motors and alternators as the stator motors can be found as either the rotating... induction motor is supplied with 22 Practical Electric Motor Handbook mechanical power and thereby made to rotate faster than the synchronous speed set by the number of poles and the line frequency, the motor becomes an induction generator delivering current into the AC power line Here, then is our elusive counter-e.m.f, at work! Here, too, is a practical insight into the nature of induction motors A... with the practical fact that a 10 hp motor must always develop a higher internal horsepower, say 11 or 12 hp, and the input power must be higher yet In other words, the rated horsepower represents the power output of the motor that is available at the shaft to do useful work The perfect conversion 24 Practical Electric Motor Handbook Fig 1.17 General configuration of the long-sought "magnetic motor" ... destroyed, but only transformed in nature There is no practical way to harness the 100% efficiency of the energy conversion process 26 Practical Electric Motor Handbook Measurement pitfalls Practical experience with motors teaches us that many useful objectives can be realized by dealing with reasonable approximations Despite the liberal tolerances permissible in motor measurements and calculations, it is nonetheless... measure of practical common sense Measuringspeed In the technical literature, one finds reference to the instantaneous speed of a synchronous motor Confusion can arise from such an allusion, for by this implied definition, such motors are supposed to run at the speed of their 16 Practical Electric Motor Handbook Fig 1.11 Greatly exaggerated view of synchronism Momentarily, the synchronous motor powered . design and operation of electric motors. Science 2 Practical Electric Motor Handbook Fig. 1.1 One of the earliest indications of motor action. To the. manifestations of electricity and magnetism had been recognized for centuries, but the utilization of a force 4 Practical Electric Motor Handbook Fig.