How do you calculate the excitation current of a transformer?
the exciting current measurement is performed by applying an aC (60hz) Voltage (typically at 10kV) across a primary winding of the transformer while simultaneously measuring the current flowing through the same primary winding (while the secondary and ter- tiary winding(s) of the transformer are open-circuited).
What is meant exciting current?
1 : a current that excites or energizes an electrical apparatus (such as the field magnets of a dynamo) 2 : the current taken by the primary of a transformer on no load.
What components compose the excitation current of a transformer?
The exciting current (Ie) has two components: the core-loss current (Ih+e) and the magnetizing current (Im). The core loss is a real-power component, due to hysteresis and eddy currents, revealed as heat generated in the core.
What is excitation current of CT?
A multi-ratio ct is voltage rated using the maximum turns ratio. The voltage read from the upper curve at 10 amps excitation current is 486 volts. … The magnetizing impedance is non-linear, increasing from 3000 ohms at 0.001 amps excitation current to a maximum of 8000 ohms at 0.0248 amperes of excitation.
What is an excitation test on a transformer?
excitation test represents the iron core saturation. This test is performed by applying a sinusoidal voltage (V2) in the secondary winding while the primary winding is opened, as shown in the Figure 5. The injected voltage produces a magnetic flux in the core, and the value of the rms current should be recorded. …
How do you find the magnetization current of a transformer?
- Apply rated voltage to the LV side of the transformer.
- Measure the no-load current Io, power Po, and input voltage Vo.
- Measure the open-circuited HV side voltage if the transformer ratio needs to be calculated.
Why excitation current of transformer is non sinusoidal?
If the transformer iron core did not saturate, the magnetizing current (Im), generated by the flux, would be sinusoidal in shape and in phase with the flux. … The result is that the magnetizing current is symmetrical, but cannot be sinusoidal due to the magnetization curve nonlinearity.
What is electrical excitation?
The process of generating a magnetic field by means of an electric current is called excitation. … The flexible excitation of a rotating electrical machine is employed by either brushless excitation techniques or by the injection of current by carbon brushes (static excitation).
What is excitation current and what are its components?
A transformer exciting current is the current or amperes required to energize the core. … The excitation current is made up of two components. The real component in the form of losses that are commonly referred to as no-load losses. The second form is reactive power measured in KVAR.
What is meant by magnetizing current?
[′mag·nə‚tiz·iŋ ‚kə·rənt] (electricity) The current that flows through the primary winding of a power transformer when no loads are connected to the secondary winding; this current establishes the magnetic field in the core and furnishes energy for the no-load power losses in the core.