Transformers TRANSFORMER EFFICIENCY A transformer does not require any moving parts to transfer energy. This means that there are no friction or windage losses, and the other losses are slight. The resulting efficiency of a transformer is high. At full load, the efficiency of a transformer is between 96% and 97%. For a transformer with […]
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Alternating current fundamentals
Transformers: Transformer efficiency , The exciting current , Primary and secondary voltage relation ships and Primary and secondary current relationships .
Transformers TRANSFORMER EFFICIENCY A transformer does not require any moving parts to transfer energy. This means that there are no friction or windage losses, and the other losses are slight. The resulting efficiency of a transformer is high. At full load, the efficiency of a transformer is between 96% and 97%. For a transformer with […]
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Transformers: Leakage flux , Exciting current and core losses, Copper losses using direct current and Transformer losses and efficiency .
LEAKAGE FLUX Some of the lines of flux produced by the primary winding do not link the turns of the secondary winding in most transformers. The magnetic circuit for this primary leakage flux is in air. In other words, the leakage flux does not follow the circuit path through the core. This flux links the […]
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Transformers: Leakage flux , Exciting current and core losses, Copper losses using direct current and Transformer losses and efficiency .
LEAKAGE FLUX Some of the lines of flux produced by the primary winding do not link the turns of the secondary winding in most transformers. The magnetic circuit for this primary leakage flux is in air. In other words, the leakage flux does not follow the circuit path through the core. This flux links the […]
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Alternating-Current Generators : Automatic voltage control, Saturation curve , Alternator nameplate data , Alternator efficiency and Paralleling alternators.
AUTOMATIC VOLTAGE CONTROL An alternator will experience large changes in its terminal voltage with changes in the load current and the load power factor because of the combined effects of the armature reactance and the armature reaction. However, a relatively constant terminal voltage can be maintained under changing load conditions by the use of an […]
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Alternating-Current Generators : Automatic voltage control, Saturation curve , Alternator nameplate data , Alternator efficiency and Paralleling alternators.
AUTOMATIC VOLTAGE CONTROL An alternator will experience large changes in its terminal voltage with changes in the load current and the load power factor because of the combined effects of the armature reactance and the armature reaction. However, a relatively constant terminal voltage can be maintained under changing load conditions by the use of an […]
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Alternating-Current Generators : Hunting.
HUNTING If the torque output of a prime mover pulsates, it may cause the rotor of the alternator to be pulled ahead of, and then behind, its normal running position. A diesel engine is one example of a prime mover that has a pulsating torque output. If an alternator is used with a diesel engine, […]
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Alternating-Current Generators : Hunting.
HUNTING If the torque output of a prime mover pulsates, it may cause the rotor of the alternator to be pulled ahead of, and then behind, its normal running position. A diesel engine is one example of a prime mover that has a pulsating torque output. If an alternator is used with a diesel engine, […]
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Alternating-Current Generators : Synchronous impedance (with armature reaction)
SYNCHRONOUS IMPEDANCE (WITH ARMATURE REACTION) Values of R and X are usually not given for alternators. A method known as the synchronous impedance test can be employed to determine these values. A single-phase alternator is shown in Figure 12–23. To perform this test, the output terminals of the alternator will be shorted by switch S. […]
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Alternating-Current Generators : Synchronous impedance (with armature reaction)
SYNCHRONOUS IMPEDANCE (WITH ARMATURE REACTION) Values of R and X are usually not given for alternators. A method known as the synchronous impedance test can be employed to determine these values. A single-phase alternator is shown in Figure 12–23. To perform this test, the output terminals of the alternator will be shorted by switch S. […]
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