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One way to reduce rotor copper loss is by controlling the speed of induction motor.
How do induction motors reduce copper loss?
Improving slot fill will help your copper loss, by putting bigger wires in the stator slot, the wire resistance will reduce and the copper loss will go down. Reducing the end turn height of the windings will also help reduce copper losses.
How can we reduce copper losses?
Copper losses are due to the resistance of the wire in the primary and secondary windings and the current flowing through them. These losses can be reduced by using wire with large cross-sectional area in the manufacturing of the coils.
How can we reduce iron losses in the induction motor?
Iron or Core Losses Since by laminating the core, area decreases and hence resistance increases, which results in decrease in eddy currents. Hysteresis losses are minimized by using high grade silicon steel.
How is copper loss calculated in an induction motor?
The rotor copper loss is calculated by subtracting the stator copper loss from the total measured loss or the rotor I2R loss.The following are the losses in an induction motor: Core loss in the stator and the rotor. Stator and rotor copper losses. Friction and windage loss.
Does copper loss depend on frequency?
Eddy current loss and hysteresis loss are almost independent of load, significantly depending on supply voltage and frequency. Copper loss varies as the square of load current and called variable loss.
What happens if motor back EMF is 0?
If there is no back end then large current flows in starting of motors because initial speed is zero and back emf is zero thus winding gets damaged for this purpose only we use starters for all motors. motor will not start.
What is core loss and copper loss?
Copper loss is the term often given to heat produced by electrical currents in the conductors of transformer windings, or other electrical devices. Copper losses are an undesirable transfer of energy, as are core losses, which result from induced currents in adjacent components.
How can hysteresis loss be reduced?
How do we Reduce Hysteresis Losses? Hysteresis losses can be reduced by using material that has less area of the hysteresis loop. Hence, high grade or silica steel can be used for designing the core within a transformer because it has extremely less area of the hysteresis loop.
What causes hysteresis loss?
Hysteresis loss in a transformer occurs due to magnetization saturation in the core of the transformer. Magnetic materials in the core will eventually become magnetically saturated when they are placed in a strong magnetic field, such as the magnetic field generated by an AC current.
What happens if fifth harmonic is given to induction motor?
It will rotates in normal operation. Either short circuit or open circuit occurs. The sinusoidal components having frequency five times of fundamental are known as fifth harmonics. Hence induction motor will rotates in reverse direction because of reverse phase sequence of fifth harmonics.
What is iron loss in transformer?
Iron loss and copper loss are part of losses in a transformer. Iron loss: This is defined as the loss that is caused due to the alternating flux in the core of the transformer. As the loss occurs in the core, therefore the iron loss is also known as core loss.
What are the losses in motor?
Intrinsic losses are of two types: fixed losses – independent of motor load, and variable losses – dependent on load. Fixed losses consist of magnetic core losses and friction and windage losses. Magnetic core losses (sometimes called iron losses) consist of eddy current and hysteresis losses in the stator.
How do you calculate copper loss?
Copper loss calculation formula: Copper loss Pc in Watts is equal to the resistance R(Ω) in ohms times of the square of the current I(A) in Amps. But the transformer has two winding such as primary winding and secondary winding.
What is output of induction motor?
Efficiency of an Induction Motor The induction motor receives power from the supply mains through the stator windings. The input power is electrical power. The power from the stator winding is transferred to rotor, via air gap by induction principle. The output power is a mechanical power.
Why is the efficiency of induction motor so poor at high slips?
When an induction motor is started, the slip value is equal to 1 since the rotor is not moving. Therefore, the induced magnetic field and current in the rotor can be very large. This in turn causes a high current to be drawn by the stator that can cause damage to the motor if not controlled.
Which factor the copper loss of a transformer depends?
(ii) Copper loss in transformer It is clear that Cu loss is proportional to square of the current, and current depends on the load. Hence copper loss in transformer varies with the load.
What factors does the additional copper losses depend upon?
What factor does the additional copper losses depend upon? Explanation: With a sinusoidal voltage impressed over the terminal of the motor, the additional copper losses are caused. They are caused due to the higher order mmf harmonics and skin effect. 5.
Is eddy current loss depends on frequency?
Thus we find eddy current loss per unit volume of the material directly depends upon the square of the frequency, flux density and thickness of the plate. Also it is inversely proportional to the resistivity of the material. The core of the material is constructed using thin plates called laminations.
What will happen if the back emf in the motor absent * 2 points?
If back emf of a dc motor vanishes suddenly, motor circuit will try to retain back emf by drawing more current from supply. As the back emf vanishes zero, the whole supply voltage appears across armature and heavy current flows.
Is back emf AC or DC?
Back EMF can have either a sinusoidal (AC) or a trapezoidal (DC) waveform. The shape of the back EMF is important, as it determines the type of drive current and commutation method that should be used for the motor.
What is back emf equation?
The back emf is calculated based on the difference between the supplied voltage and the loss from the current through the resistance. The power from each device is calculated from one of the power formulas based on the given information. The back emf is ϵi=ϵS−I(Rf+REa)=120V−(10A)(2.0Ω)=100V.
