Transformer KVA formula and calculator

KVA calculations for transformers are vital to determine the transformer's capacity, ensuring it can handle the electrical load efficiently and safely. By calculating KVA, one can size transformers appropriately, maintain stable voltage levels, optimize energy efficiency, and meet compliance standards, all of which are essential for the reliable and cost-effective operation of electrical systems.

The formula to calculate the apparent power (in kVA) for both single-phase and three-phase transformers is based on the rated voltage and rated current.

transformer KVA to current/voltage formula

As mentioned the formula for single-phase transformers is straightforward, while the formula for three-phase transformers takes into account the square root of 3 (approximately 1.732) due to the phase difference between the currents in a three-phase system. In the formula, KVA is apparent power in kilovolt-ampere (KVA), "V" is the rated voltage of the transformer and "I" is the rated current of the transformer.

Single Phase Transformer KVA Calculator

INPUTS

Primary Voltage (input1) :

Primary Current (input2) :



OUTPUT

Single Phase Transformer KVA (Output):

Example of Single Phase KVA calculation :
Voltage = 11000 volt , current = 5.75 Amp
Single phase transformer KVA = 63.25 KVA

3 Phase Transformer Calculator

INPUTS

Primary Voltage (input1) :

Primary Current (input2) :



OUTPUT

Three Phase Transformer KVA (Output):

Example of 3 phase transformer calculation :
Voltage = 11000 volt , current = 5.75 Amp
Single phase transformer KVA = 109.55 KVA

Conclusion : The KVA calculator determines the apparent power rating of transformers, a crucial parameter in electrical systems. These calculations for single phase and 3 phase transformers are very essential for selecting the right transformer size, ensuring voltage regulation, optimizing efficiency and maintaining safety in electrical systems. Also refer Transformer basics and types.


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