top of page


Público·31 membros

Electrical Machines Textbook Pdf 13

Abstract:This paper investigates and compares the torque-generating capabilities and electromagnetic performance of advanced non-overlapping winding induction machines (AIM), conventional induction machines (CIM), and interior-permanent magnet (IPM) machines for electric vehicle (EV) applications. All investigated machines are designed based on the specifications of the Toyota Prius 2010 IPM machine. The steady-state and flux-weakening performance characteristics are calculated by employing the 2D finite element method and MatLab, and the obtained results are quantitatively compared. Furthermore, the torque-generating capabilities of three machines are investigated for different electric loadings, and the machine having the highest torque-generating capability is determined as AIM. Moreover, the major parameters affecting the torque-generating capability, such as magnetic saturation and magnet demagnetization, are examined in depth.Keywords: electric vehicles; induction machine; interior permanent magnet machine; non-overlapping winding; saliency; torque capability

electrical machines textbook pdf 13

Download File:

Electrical Machines and Drives by Jan A Melkebeek pdf free download. This work can be used as a comprehensive study and reference textbook on the most common electrical machines and drives. In contrast with many textbooks on drives, this book goes back to the fundamentals of electrical machines and drives, following in the footsteps of the traditional textbooks written by Richter and Bödefeld & Sequenz in German.

From the fan motor in your PC to precision control of aircraft, electrical machines of all sizes, varieties, and levels of complexity permeate our world. Some are very simple, while others require exacting and application-specific design. Electrical Machine Analysis Using Finite Elements provides the tools necessary for the analysis and design of any type of electrical machine by integrating mathematical/numerical techniques with analytical and design methodologies.Building successively from simple to complex analyses, this book leads you step-by-step through the procedures and illustrates their implementation with examples of both traditional and innovative machines. Although the examples are of specific devices, they demonstrate how the procedures apply to any type of electrical machine, introducing a preliminary theory followed by various considerations for the unique circumstance. The author presents the mathematical background underlying the analysis, but emphasizes application of the techniques, common strategies, and obtained results. He also supplies codes for simple algorithms and reveals analytical methodologies that universally apply to any software program.With step-by-step coverage of the fundamentals and common procedures, Electrical Machine Analysis Using Finite Elements offers a superior analytical framework that allows you to adapt to any electrical machine, to any software platform, and to any specific requirements that you may encounter.

Electrical machines with matlab second edition by Turan Gonen. This easy-reading text for introductory-level electric machinery courses is a cross-disciplinary design book for engineering students. Basic material is explained carefully and in detail with numerous examples included to aid comprehension. This book is an ideal self-study tool for advanced students in electrical and other areas of engineering. In response to the often inadequate, rushed coverage of fundamentals in most basic circuit analysis books and courses, this resource is intelligently designed, easy to read, and packed with in-depth information on crucial concepts.

No, the electrical PE power exam will not be CBT in 2019. According to the NCEES website, the schedule to move the electrical power PE exam to CBT (computer-based) is tentatively set for 2021 and may be pushed further back.

An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of torque applied on the motor's shaft. An electric generator is mechanically identical to an electric motor, but operates with a reversed flow of power, converting mechanical energy into electrical energy.

Electric motors produce linear or rotary force (torque) intended to propel some external mechanism, such as a fan or an elevator. An electric motor is generally designed for continuous rotation, or for linear movement over a significant distance compared to its size. Magnetic solenoids are also transducers that convert electrical power to mechanical motion, but can produce motion over only a limited distance.

A benefit to DC machines came from the discovery of the reversibility of the electric machine, which was announced by Siemens in 1867 and observed by Pacinotti in 1869.[6] Gramme accidentally demonstrated it on the occasion of the 1873 Vienna World's Fair, when he connected two such DC devices up to 2 km from each other, using one of them as a generator and the other as motor.[25]

Electric motors revolutionized industry. Industrial processes were no longer limited by power transmission using line shafts, belts, compressed air or hydraulic pressure. Instead, every machine could be equipped with its own power source, providing easy control at the point of use, and improving power transmission efficiency. Electric motors applied in agriculture eliminated human and animal muscle power from such tasks as handling grain or pumping water. Household uses (like in washing machines, dishwashers, fans, air conditioners and refrigerators (replacing ice boxes)) of electric motors reduced heavy labor in the home and made higher standards of convenience, comfort and safety possible. Today, electric motors consume more than half of the electric energy produced in the US.[29]

The two mechanical parts of an electric motor are the rotor, which moves, and the stator, which does not. It also includes two electrical parts, a set of magnets and an armature, one of which is attached to the rotor and the other to the stator, together forming a magnetic circuit:[49]

An air gap between the stator and rotor allows it to turn. The width of the gap has a significant effect on the motor's electrical characteristics. It is generally made as small as possible, as a large gap weakens performance. It is the main source of the low power factor at which motors operate. The magnetizing current increases and the power factor decreases with the air gap, so narrow gaps are better. Conversely, gaps that are too small may pose mechanical problems in addition to noise and losses.

The stator surrounds the rotor, and usually holds field magnets, which are either electromagnets consisting of wire windings around a ferromagnetic iron core or permanent magnets. These create a magnetic field that passes through the rotor armature, exerting force on the windings. The stator core is made up of many thin metal sheets that are insulated from each other, called laminations. These laminations are made using electrical steel which has a specified magnetic permeability, hysteresis, and saturation. Laminations are used to reduce losses that would result from induced circulating eddy currents that would flow if a solid core were used. Mains powered AC motors typically immobilize the wires within the windings by impregnating them with varnish in a vacuum. This prevents the wires in the winding from vibrating against each other which would abrade the wire insulation causing it to fail prematurely. Resin-packed motors, used in deep well submersible pumps, washing machines, and air conditioners, encapsulate the stator in plastic resin to prevent corrosion and/or reduce conducted noise.[52]

Electric machines come in salient- and nonsalient-pole configurations. In a salient-pole motor the ferromagnetic cores on the rotor and stator have projections called poles facing each other, with a wire winding around each pole below the pole face, which become north or south poles of the magnetic field when current flows through the wire. In a nonsalient-pole (or distributed field or round-rotor) motor, the ferromagnetic core is a smooth cylinder, with the windings distributed evenly in slots about the circumference. Supplying alternating current in the windings creates poles in the core that rotate continuously.[53] A shaded-pole motor has a winding around part of the pole that delays the phase of the magnetic field for that pole.

A commutator is a rotary electrical switch that supplies current to the rotor. It periodically reverses the flow of current in the rotor windings as the shaft rotates. It consists of a cylinder composed of multiple metal contact segments on the armature. Two or more electrical contacts called "brushes" made of a soft conductive material like carbon press against the commutator. The brushes make sliding contact with successive commutator segments as it rotates, supplying current to the rotor. The windings on the rotor are connected to the commutator segments. The commutator periodically reverses the current direction in the rotor windings with each half turn (180), so the torque applied to the rotor is always in the same direction.[54] Without this current reversal, the direction of torque on each rotor winding would reverse with each half turn, so the rotor would stop. Commutators are inefficient and commutated motors have been mostly replaced by brushless direct current motors, permanent magnet motors, and induction motors.

A permanent magnet (PM) motor does not have a field winding on the stator frame, relying instead on PMs to provide the magnetic field. Compensating windings in series with the armature may be used on large motors to improve commutation under load. This field is fixed and cannot be adjusted for speed control. PM fields (stators) are convenient in miniature motors to eliminate the power consumption of the field winding. Most larger DC motors are of the "dynamo" type, which have stator windings. Historically, PMs could not be made to retain high flux if they were disassembled; field windings were more practical to obtain the needed flux. However, large PMs are costly, as well as dangerous and difficult to assemble; this favors wound fields for large machines. 350c69d7ab


Bem-vindo ao grupo! Você pode se conectar com outros membros...
Página do Grupo: Groups_SingleGroup
bottom of page