A Distribution Transformer is Energized All day on Primary side with Varying Loads on Secondary Side. Consumer’s Power Consumption varies with time to time during whole day, So Loading on Distribution Transformer is not uniform. Copper loss depends on Loading of Transformer, So during All day as Load changes copper will also change.
All day efficiency is mostly less than commercial efficiency of Transformer.
For Calculating All day efficiency of Transformer we should know Load cycle of Transformer during whole day.
Steps to calculate All day Efficiency:-
Calculate Output Energy of Transformer.
Calculate the Loss of Energy due to Iron Loss.
Calculate the Copper loss at various time intervals.
Do sum of above three as input, from this calculation find All day Efficiency.