Substation1
Dictionary of Electrical Engineering

Commonly used terms in the Electrical industry.

unbalanced operation
in an n-phase system (n> 1), a condition in which the phase voltages (currents) are either

1. not equal-amplitude sinusoids or

2. have phase angles displaced by a value other than that specified for balanced operation.

The term "unbalanced" is also used to describe a machine that has unsymmetrical phase windings.