Example of Per-unit
As an example of how per-unit is used, consider a three-phase power transmission system that deals with powers of the order of 500 MW and uses a nominal voltage of 138 kV for transmission. We arbitrarily select MVA, and use the nominal voltage 138 kV as the base voltage . We then have:
If, for example, the actual voltage at one of the buses is measured to be 136 kV, we have:
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