the circle diagram of induction motor is used to find the losses and efficiency of induction motor
Just like a transformer, the core losses are a combination of eddy current losses and hysteresis losses.
Stray losses refer to secondary voltage to be inappropriately distributed to transformers, induction motors and generators. Stray losses essentially mean that there is leakage that causes a weakening of the voltage being delivered to the motor.
yes
There is hardly 1.5 to 2.0% loss in induction melting of steel but even it can be also avoided with the help of covering of crucibles. just open it at the time of charging only is the best practise to avoid oxidation & heat losses for Induction melting for steel.
for oil fired furnace it is 4% , n for induction billte heater it is around 1%.
Yes, the output line used to find the losses, usually for smaller machines we take copper losses equal to the iron losses.
Circle diagram of an induction motor is plotted set of lines , arcs, and angles graphically depicting induction motor performance, derived from simple no-load and locked-rotor tests. A motor's "conventional" efficiency was determined based on four losses only: stator and rotor I2R, core loss, and friction and windage. Each of them could be evaluated with acceptable accuracy from tests without shaft load, through use of a circle diagram. Other than this all operational performances of an induction motor can be calculated by circe diagram without actually loading the machine.You can not count the advantages of the circle diagram only when you use it.
It is maximum at about 75% to 100% of the motor rated load. Efficiency is maximum at unity power factor , when R=X and when variable losses Is equal to constant losses at rated load.
what are the various losses occurring in the motors
Impedence
Just like a transformer, the core losses are a combination of eddy current losses and hysteresis losses.
The condition for maximum efficiency of a d.c. machine is that VARIABLE LOSSES must be equal to CONSTANT LOSSES i.e., variable losses = constant losses..
Stray losses refer to secondary voltage to be inappropriately distributed to transformers, induction motors and generators. Stray losses essentially mean that there is leakage that causes a weakening of the voltage being delivered to the motor.
Because, the losses of IM is more due to the contribution of friction losses at shaft bearings and wind age losses in rotor air gap, this reduces the efficiency of the equipment, Since transforms is a static equipment zero mechanical loss so efficiency of the equipments in high .
yes
The input power, Pin, is reduced by different loss sources in the system. These reductions are the difference between input power & output power. The losses are: PSCL: Stator copper losses, or I2R losses Pcore: Core losses PRCL: Rotor copper losses PF&W: Friction & windage losses Pmisc: miscellaneous losses All of these losses reduce the input power. The output power is the input power minus all of the losses. Pout = Pin - PSCL - Pcore - PRCL - PF&W - Pmisc
Iron Loss Copper Loss Frictional loss