in Word Doc Format
... (B) lags behind the flux by 90 degree. (C) leads the flux by 90 degree. (D) is in phase opposition to that of flux. Ans: C Q.18 The relative speed between the magnetic fields of stator and rotor under steady state operation is zero for a (A) dc machine. (B) 3 phase induction machine. (C) synchronous ...
... (B) lags behind the flux by 90 degree. (C) leads the flux by 90 degree. (D) is in phase opposition to that of flux. Ans: C Q.18 The relative speed between the magnetic fields of stator and rotor under steady state operation is zero for a (A) dc machine. (B) 3 phase induction machine. (C) synchronous ...
Chapter 4 Delta Wiring Topologies
... Let us review the technical disclosures presented in the figures from the patent. The Stator Commutator Chamber: Again consider Figure 11 and look at the left half of the illustration. This part of the system involves connections that are believed to control the stator electromagnets. There are 6 co ...
... Let us review the technical disclosures presented in the figures from the patent. The Stator Commutator Chamber: Again consider Figure 11 and look at the left half of the illustration. This part of the system involves connections that are believed to control the stator electromagnets. There are 6 co ...
Three-Phase Induction Motor
... The squirrel-cage induction motor is already mounted to the dynamometer. Note that the pulley system ratio is 1:1. Therefore, the motor being tested operates at same the speed of dynamometer. The motor is rated for 1/3 horsepower, 208VL-L, and 1725 RPM. Its rated full-load current is 1.2 amperes. Th ...
... The squirrel-cage induction motor is already mounted to the dynamometer. Note that the pulley system ratio is 1:1. Therefore, the motor being tested operates at same the speed of dynamometer. The motor is rated for 1/3 horsepower, 208VL-L, and 1725 RPM. Its rated full-load current is 1.2 amperes. Th ...
2 marks EC2201
... 7. What are the methods of speed contol in Induction motors? 1. Control from stator side (a) By changing the applied voltage (b) By changing the applied frequency C By Changing the number of stator poles 2. Control from rotor side (d) rotor rheostat control (e) by operating two motors in concatenati ...
... 7. What are the methods of speed contol in Induction motors? 1. Control from stator side (a) By changing the applied voltage (b) By changing the applied frequency C By Changing the number of stator poles 2. Control from rotor side (d) rotor rheostat control (e) by operating two motors in concatenati ...
E701 ELECTRICAL MACHINES III
... 1. The frequency of e.m.f in the stator of a 4 pole induction motor is 50 Hz and that in the rotor is 1.5 Hz. What is the slip and at what speed the motor is running? 2. A 3.3kV, 20 pole, 50 Hz, 3 phase Induction Motor has rotor resistance and standstill reactance of 0.014Ω and 0.113Ω per phase resp ...
... 1. The frequency of e.m.f in the stator of a 4 pole induction motor is 50 Hz and that in the rotor is 1.5 Hz. What is the slip and at what speed the motor is running? 2. A 3.3kV, 20 pole, 50 Hz, 3 phase Induction Motor has rotor resistance and standstill reactance of 0.014Ω and 0.113Ω per phase resp ...
World`s Simplest Motor
... Electric motors convert the electric energy from an AC (house electric lines in the US carry AC, or Alternating Current) or DC power source (the electricity produced by solar cells, batteries, and other sources, DC or Direct Current, is also how home electricity is delivered in Europe and many other ...
... Electric motors convert the electric energy from an AC (house electric lines in the US carry AC, or Alternating Current) or DC power source (the electricity produced by solar cells, batteries, and other sources, DC or Direct Current, is also how home electricity is delivered in Europe and many other ...
Celiano Portero - Stevens Institute of Technology
... unbalance, the output voltage and frequency are variable and cannot provide a stable power supply. The produced power must be run through a rectifier and an inverter to be compatible with a 60 Hz power system. Due to the small capacity and higher cost per kilowatt of output, this type is not suit-ab ...
... unbalance, the output voltage and frequency are variable and cannot provide a stable power supply. The produced power must be run through a rectifier and an inverter to be compatible with a 60 Hz power system. Due to the small capacity and higher cost per kilowatt of output, this type is not suit-ab ...
GRADE 8: Physical processes 2 Electromagnetism UNIT 8P.2 8 hours
... Challenge the group to design an investigation that will find out what is the best material for making the core of an electromagnet. Discuss the results of this investigation with the class. Draw from them, and list on the board or OHP for them to note as important conclusions, the following: • only ...
... Challenge the group to design an investigation that will find out what is the best material for making the core of an electromagnet. Discuss the results of this investigation with the class. Draw from them, and list on the board or OHP for them to note as important conclusions, the following: • only ...
Generators - GE Power Conversion
... Class H performance. At intervals down each coil side, individual turns may be extended to improve cooling. Coils are assembled on epoxy bonded glass laminate washers. Each fully insulated coil unit is then mounted on its salient pole with a suitable restraining arrangement to ensure that it is held ...
... Class H performance. At intervals down each coil side, individual turns may be extended to improve cooling. Coils are assembled on epoxy bonded glass laminate washers. Each fully insulated coil unit is then mounted on its salient pole with a suitable restraining arrangement to ensure that it is held ...
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.