Principles of Doubly-Fed Induction Generators (DFIG)
... machines used as doubly-fed induction generators. In a conventional three-phase synchronous generator, when an external source of mechanical power (i.e., a prime mover) makes the rotor of the generator rotate, the static magnetic field created by the dc current fed into the generator ) as the rotor. ...
... machines used as doubly-fed induction generators. In a conventional three-phase synchronous generator, when an external source of mechanical power (i.e., a prime mover) makes the rotor of the generator rotate, the static magnetic field created by the dc current fed into the generator ) as the rotor. ...
MagnaMaxDVR® Installation, Operation, and
... humid areas, such as the tropics and marine service, additional protection is recommended. Although the standard windings are humidity and moisture resistant, special insulations and accessories such as space heaters can increase generator life significantly. In extremely dirty and dusty environment ...
... humid areas, such as the tropics and marine service, additional protection is recommended. Although the standard windings are humidity and moisture resistant, special insulations and accessories such as space heaters can increase generator life significantly. In extremely dirty and dusty environment ...
Measuring instrument of the potentiometer type
... in that only two relays are used with a condenser is placed in circuit with the relays 36 or‘ 3|. in each relay circuit serving to permit the neces The voltage divider 46 is supplied from an A. C. sary time delay during which the motor 34 is ‘source through a copper oxide recti?er 45 of energized fo ...
... in that only two relays are used with a condenser is placed in circuit with the relays 36 or‘ 3|. in each relay circuit serving to permit the neces The voltage divider 46 is supplied from an A. C. sary time delay during which the motor 34 is ‘source through a copper oxide recti?er 45 of energized fo ...
AC Generators with 2/3rd and 5/6th winding pitch 429.56 KB
... fan motors, lifts, etc. What is not always appreciated is that although many of these ‘normal’ loads appear to be benign with respect to harmonic distortion, many now contain variable frequency drives etc., which are harmonically distorting, and can also be susceptible to a harmonically distorted su ...
... fan motors, lifts, etc. What is not always appreciated is that although many of these ‘normal’ loads appear to be benign with respect to harmonic distortion, many now contain variable frequency drives etc., which are harmonically distorting, and can also be susceptible to a harmonically distorted su ...
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High-Power-Factor Vernier Permanent
... Vernier permanent-magnet (VPM) machines have simple structure and high torque density due to the so-called magnetic gear effect [5]–[8]. In addition, the VPM machine has low pulsing torque due to its more sinusoidal electromotive force (EMF) waveform, as compared to that of a regular PM machine [9]; ...
... Vernier permanent-magnet (VPM) machines have simple structure and high torque density due to the so-called magnetic gear effect [5]–[8]. In addition, the VPM machine has low pulsing torque due to its more sinusoidal electromotive force (EMF) waveform, as compared to that of a regular PM machine [9]; ...
The effect of voltage dips on wound rotor induction motors used in
... disturbances such as voltage dips. The failure of converters as a result of voltage dips is a problem associated with the use of these drives. The aim of this research is to better understand the stresses on rotor circuit converters as a result of voltage dips at the terminals of the motor. The roto ...
... disturbances such as voltage dips. The failure of converters as a result of voltage dips is a problem associated with the use of these drives. The aim of this research is to better understand the stresses on rotor circuit converters as a result of voltage dips at the terminals of the motor. The roto ...
3-Phase PM Synchronous Motor Nyachulue Njita High Speed with Low Torque
... magnetic field and rotates with it together. The speed of these special motors is varied by changing the frequency and the number of poles of the motor. When the operating frequency rises, the speed of the motor rises and can only drop drastically when the number of poles is increased. Unless the fr ...
... magnetic field and rotates with it together. The speed of these special motors is varied by changing the frequency and the number of poles of the motor. When the operating frequency rises, the speed of the motor rises and can only drop drastically when the number of poles is increased. Unless the fr ...
Eliminating Damage from Motor Shaft Currents - Nidec
... create a circulating current path through ground (Figure 4), which can damage the un-insulated motor bearing as previously outlined. Modular Encoders: Modular encoders (also called pancake or C-face mount) are inherently isolated electrically by their design and do prevent shaft current discharge. A ...
... create a circulating current path through ground (Figure 4), which can damage the un-insulated motor bearing as previously outlined. Modular Encoders: Modular encoders (also called pancake or C-face mount) are inherently isolated electrically by their design and do prevent shaft current discharge. A ...
Commutator (electric)
A commutator is the moving part of a rotary electrical switch in certain types of electric motors and electrical generators that periodically reverses the current direction between the rotor and the external circuit. It consists of a cylinder composed of multiple metal contact segments on the rotating armature of the machine. The commutator is one component of a motor; there are also two or more stationary electrical contacts called ""brushes"" made of a soft conductor like carbon press against the commutator, making sliding contact with successive segments of the commutator as it rotates. The windings (coils of wire) on the armature are connected to the commutator segments. Commutators are used in direct current (DC) machines: dynamos (DC generators) and many DC motors as well as universal motors. In a motor the commutator applies electric current to the windings. By reversing the current direction in the rotating windings each half turn, a steady rotating force (torque) is produced. In a generator the commutator picks off the current generated in the windings, reversing the direction of the current with each half turn, serving as a mechanical rectifier to convert the alternating current from the windings to unidirectional direct current in the external load circuit. The first direct current commutator-type machine, the dynamo, was built by Hippolyte Pixii in 1832, based on a suggestion by André-Marie Ampère. Commutators are relatively inefficient, and also require periodic maintenance such as brush replacement. Therefore, commutated machines are declining in use, being replaced by alternating current (AC) machines, and in recent years by brushless DC motors which use semiconductor switches.