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Why does the open-circuit test essentially show only excitation losses and not in copper losses?
Oh, dude, the open-circuit test is like when you're checking out a car but not actually driving it - you're just seeing how it revs up without any load. So, it's all about measuring the excitation losses because there's no current flowing through the windings to cause copper losses. It's like checking out a car's engine without actually taking it for a spin - you're just seeing how it purrs without any real work.
What else can I help you with?
Why does the short-circuit test essentially show only PR losses and not excitation losses in a transfonner?
Because a short-circuit test is done at low voltage so there is very small power loss in the magnetic core. That is because there is very magnetic flux.
What are the Advantages and disadvantages of delta and wye transformers?
copper losses Comment: Advantages: Their operation is silent They have a high efficiency They are relatively safe Disadvantages Expensive Copper losses and hysteress losses
Why the rotor of an alternator at rated power dissipates more heat at a low power factor load?
In an alternator, the load current is supplied by the stator and the excitation is applied to the rotor. When the power factor is low (lagging), more excitation is required to maintain rated output voltage at rated current. More excitation is also required to maintain rated output voltage with increased output current. Increased excitation current means increased rotor losses that must be dissipated as heat. (akash)
What components comprise the excitation current of a transformer?
A transformer's excitation current can be resolved into two components. The first is in phase with the primary voltage, and is responsible for the losses. The second lags the supply voltage by 90 degrees, and is responsible for magnetising the core.
Explain the power flow diagram of induction motor?
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
Why does the short-circuit test essentially show only i2R losses and not excitation losses in a transformer?
The short-circuit test on a transformer primarily assesses the copper losses, represented by i²R losses, because it is performed at a reduced voltage that allows full-load current to flow while keeping the output voltage low. In this condition, the magnetic circuit is already magnetized from prior tests, so the core does not require significant additional magnetizing current, thus minimizing excitation losses. Consequently, the test focuses on the resistive losses in the windings rather than losses due to hysteresis or eddy currents in the core.
Why does the short-circuit test essentially show only PR losses and not excitation losses in a transfonner?
Because a short-circuit test is done at low voltage so there is very small power loss in the magnetic core. That is because there is very magnetic flux.
How is copper losses reduced in transformers?
how to reduce copper losses in a transformer Copper losses are due to the resistance of the copper (or aluminum) windings. To reduce copper losses the transformer would have to be rewound with heavier gage wire.
What are the different types of magnetic losses occurring in ferromagnetic materials under AC excitation?
types of magnetic losses
How do you calculate copper losses?
copper losses are power losses due to flow of current in the wires or resistances,if the resistance is R, current is I then copper losses are I2R. for a 3-phase system; copper losses are same but for a single line, total losses are 3I2R.
How do you calculate copper in dc motor?
Copper is not something that is calculated. The amount of copper might be, or copper losses / load losses, might be, but "copper" is not calculated.
Where does copper losses in dc machines?
Copper losses are also referred to as I^2 R losses. Copper loss is due to heating due to the current passing through the copper windings.
What are copper losses in a transformer?
Copper losses are purely voltage-drop losses (I squared R) caused by the resistance of the windings, as opposed to hysteresis losses and eddy current losses (so-called iron losses), which are magnetic in nature. They are called copper losses whether the winding conductors are made of copper or not, by the way.
Can a Auto transformer have more load losses than its no load losses?
Power transformers have both no load and full load losses. The key is copper wiring, as copper varies with the square inches of the secondary and primary currents.
What are the reasons for for the decrease in terminal voltage of a seperately excited generator?
The decrease in terminal voltage of a separately excited generator can be attributed to several factors, including increased load demand, which causes a drop in output voltage due to the internal resistance of the generator. Additionally, losses such as copper losses (I²R losses) in the armature and excitation system, as well as core losses, can contribute to a reduction in voltage. Another factor could be a decrease in the excitation current, which reduces the magnetic field strength and subsequently lowers the generated voltage. Lastly, any faults or issues in the electrical connections or components can also lead to decreased terminal voltage.
What is the significant relationship of the no load loss in excitation current test in transformer?
The no load losses are the losses caused by energizing the transformer. These are constant losses, regardless of loading. This in effect tells you the efficiency of the transformer. (Power in) - (no load losses) = (Power out)
Why is copper loss negligible during open circuit test?
Copper losses are energy losses from the windings, due to the currents passing through them. During an open-circuit test, there is no secondary current (so no secondary copper losses) and the primary current is very low (so the primary copper losses are minimum).
