The term, 'percentage impedance', is a little misleading, as it is defined as 'the value of primary voltage that will cause rated current to flow in the secondary winding, expressed as a percentage of the rated primary voltage'.
So, the test is carried out as follows: the secondary winding is short-circuited through an ammeter capable of reading the rated secondary current. A variable voltage is applied to the primary winding. The primary voltage is gradually increased until the ammeter indicates rated secondary current. That primary voltage is then expressed as a percentage of the rated primary voltage -and that value is the transformer's 'percentage impedance'.
Without a load the secondary current is zero, by definition.
The secondary current is determined by the load. So, divide the secondary voltage by the load impedance.
Inherently, the actual impedance seen at the secondary voltage will be different than that seen at the primary voltage. To make things easy, we use symmetrical components, where transformers are reduced to a p.u. (per unit) impedance. 100 x p.u. is equivalent to the percentage impedance you are referring to. When converted to per unit, a transformer has one impedance, not two, so it does not matter whether you are looking through the transformer from the secondary or the primary.
Transformer capacity (kvA) shall be identical, Both transformer impedance, secondary voltage and frequency shall be identical.
In electrical engineering, the percentage impedance of a transformer is the voltage drop on a full load, which is expressed as a percentage of the specified rated voltage. It's measured by conducting a short circuit test.
Without a load the secondary current is zero, by definition.
The secondary current is determined by the load. So, divide the secondary voltage by the load impedance.
The apparent impedance looking into a transformer from one side will not be the same as looking in it from the other, which is why percent impedance is used. If you are looking from the high voltage winding (I'm labeling #1) to the low voltage winding (#2), you must scale the percent impedance as follows: (% impedance) x (Winding #1 nominal voltage)^2 / (transformer base VA)
transformer coupling ensures maximum power transfer is obtained even if the output impedance is not equal to the load impedance
Inherently, the actual impedance seen at the secondary voltage will be different than that seen at the primary voltage. To make things easy, we use symmetrical components, where transformers are reduced to a p.u. (per unit) impedance. 100 x p.u. is equivalent to the percentage impedance you are referring to. When converted to per unit, a transformer has one impedance, not two, so it does not matter whether you are looking through the transformer from the secondary or the primary.
The lower the impedance, the lower the voltage drop across the transformer as it is loaded. This means regulation is better, since voltage variance is smaller.
To calculate the admittance if you are given the impedance, you take the inverse of the impedance ( that is 1/z).
If the line impedance is Z0 and the load is ZL then connect the load using a transformer with N turns ration. N=sqrt(Z0/ZL)
Basically the characteristics of a transformer depends on the impedance(resistance) and on the coupling of its primary and secondary coils. The impedance of a coil depends on the frequency, as the frequency increases you need less volume of iron core and less number of turns in the coil for a given impedance, then reducing the size of the transformer.
Oh, dude, a low impedance transformer on regulation? It's like having a really chill friend who always has your back. Basically, a low impedance transformer helps maintain a stable output voltage even when there are fluctuations in the input voltage. So, it's like the transformer saying, "I got you, bro," and keeping things running smoothly.
main volage
The transformer impedance is the amount of voltage applied for transformer during the load test.Answer.I really don't agree with the answer given by the previous user.Impedance is the total vector opposition offered by the transformer to the flow of current i.e the vector sum of its pure resistance (R) and it's inductive reactance (XL). http://en.wikipedia.org/wiki/Electrical_impedanceAnother AnswerThe 'impedance' of a transformer is usually expressed as a 'percentage impedance', which is defined (perhaps rather confusingly!) as the ratio of the primary voltage that will result in the full rated current flowing through the secondary, to the rated primary voltage.