Transcript Losses, Efficiency, and Power Factor • Core losses • power losses (I

Losses, Efficiency, and Power Factor
• Core losses
– hysteresis and eddy-current losses in the
stator and the rotor
• power losses (I2R losses) in the stator
windings
– stator copper losses, also called stator
conductor losses
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Net Power Crossing the Air Gap
Pgap  Pin  Pcore  Pscl
Power-Flow Diagram
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Look at Total Power Loss
Ploss  Pscl  Pcore  Prcl  Pf ,w  Pstray
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Useful Shaft Power Output
Pshaft  Pmech  Pf , w  Pstray
Pshaft 
Tshaft nr
5252
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Efficiency and Power Factor
Efficiency is the ratio of useful power out
to the total power in.

Pshaft
Pin
Power Factor is the ratio of active power to
apparent power.
Pin
Fp 
Sin
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