6.What is Percentage Impedance? Importance in short circuit current? Calculate short circuit current?

Question

Accepted Answer

Percentage Impedance is a measure of the voltage drop in a transformer during a short circuit. It determines the ability of the transformer to withstand short circuit currents.

Percentage Impedance is the ratio of the rated voltage of a transformer to the short circuit current at its terminals, expressed as a percentage.
It represents the internal impedance of the transformer and is usually provided by the manufacturer.
A higher percentage impedance means a higher voltage drop during a short circuit, which can affect the performance of the transformer.
The importance of percentage impedance lies in its impact on the fault level and voltage regulation of the power system.
It helps in determining the maximum fault current that a transformer can safely withstand without excessive voltage drop.
Short circuit current can be calculated using the formula: Short Circuit Current = Rated Voltage / Percentage Impedance.

Asked in Burns & McDonnell

6.What is Percentage Impedance? Importance in short circuit current? Calculate short circuit current?

Top Electrical Design Engineer Interview Questions Asked at Burns & McDonnell

Interview Questions Asked to Electrical Design Engineer at Other Companies