Transformer Primary and secondary currents

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SUMMARY

The discussion focuses on calculating the secondary turns and rated currents of a single-phase transformer with a rating of 120 kVA, primary voltage of 2000 V, and secondary voltage of 100 V. The correct calculation for secondary turns is determined using the formula Vp/Vs = Np/Ns, resulting in 50 secondary turns. For the rated primary current, dividing the apparent power (120,000 VA) by the primary voltage (2000 V) yields 60 A. The secondary current is then calculated using the power conservation principle, leading to a secondary current of 3 A, assuming 100% efficiency.

PREREQUISITES
  • Understanding of transformer operation and terminology
  • Familiarity with the equations Vp/Vs = Np/Ns and power conservation in transformers
  • Basic electrical engineering concepts, including voltage, current, and power
  • Knowledge of single-phase transformer ratings and specifications
NEXT STEPS
  • Study transformer efficiency and its impact on current calculations
  • Learn about three-phase transformer configurations and calculations
  • Explore practical applications of transformers in electrical systems
  • Investigate the effects of load variations on transformer performance
USEFUL FOR

Electrical engineering students, professionals working with transformers, and anyone involved in power distribution and electrical system design.

jitznerd
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Homework Statement



A single phase transformer has the following rating : 120kVA. 2000v/100v, 60 Hz with
1000 primary turns.

Determine:

a.Secondary turns
b.The rated primary and secondary currents

Homework Equations



Vp/Vs = Np/Ns

The Attempt at a Solution



a. I have used the Vp/Vs = Np/Ns to work out secondary turns
1000 x 100/2000 which gave me 50 secondary turns.

b. I arent sure if I have gone about this the right way and just wanted to check.

I divided the 120000VA by the primary voltage of 2000 to give me 60A. Is this correct to do this.
Then with my 60A I put that into the Vp/Vs = Ip/Is which gave me 3A as secondary current.

Could someone please tell me if this is correct thanks
 
Physics news on Phys.org
Vp/Vs = Ip/Is is not the correct equation... have another look at it.
If the transformer is 100% efficient then power supplied = power delivered.
 
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