Short Circuit Test of Transformer
It is a method in electrical engineering used to determine the copper or winding loss and also it determines the impedance of the transformer . The circuit diagram of this is shown below. In this, the secondary winding (low voltage side is shorted by a thick conductor) and on primary side(high voltage side) Ammeter(A), Voltmeter(V) and wattmeter(W) are connected.
Transformer
so, generally short circuit test is performed on high winding side and short circuited on low winding side. It will read copper losses because of high current passing through windings.
we have Power losses ( W s. c) = I2 s. c * Re
Hence, Re = W s c / I2s.c
we know that, Impedance( Z e ) = Vs .c / Is. c
Reactance(X e ) = sqrt((impedance)2 – (resistance)2 )
Example:
A short circuit test is conducted on a transformer and noted the following recordings V s .c = 7V , Is .c = 1.5mA , W s .c = 4W, Calculate the Reactance(X e ) , resistance(Re ) ?
Solution:
Given that, V s. c = 7V , I s. c = 1.5mA , W s . c = 4W
now, resistance ( Re ) = W s. c / I2 s. c
so, Resistance (Re ) = 1.8Ω
Impedance(Z e ) = V s .c / I s. c => 7/1.5
Now, Reactance( X e ) = sqrt((impedance)2 – (resistance)2 )
X e = 1.46Ω
Open and Short Circuit Test of Transformer
In this article, we will go through the Open and Short circuit tests of a Transformer. Open and short circuit tests are performed on a Transformer to evaluate its performance characteristics and parameters which mainly determine the Voltage regulation of the transformer, the Transformer’s efficiency, and the Equivalent circuit of the Transformer. They determine Iron and copper losses in the transformer. In this tutorial, we will go through the open and short circuit tests on a transformer with their circuit diagrams and an example and also we will tabulate the differences between the two.
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