ABSTRACT
In many engineering situations, it is useful to scale or normalize quantities. This is commonly done in power system analysis, and the standard method used is referred to as the per-unit system. Historically, this was done to simplify numerical calculations that were made by hand. Although this advantage has been eliminated by using the computer, other advantages remain:
Device parameters tend to fall into a relatively narrow range, making erroneous values conspicuous.
The method is defined in order to eliminate ideal transformers as circuit components.
The voltage throughout the power system is normally close to unity.
