Getting a clear picture of distortion [power system harmonics]

The days of using the square root of three to convert between line-to-line and line-to-neutral voltages and current values are in the past. The proliferation of rectified-input power supplies and other nonlinear loads, along with the increase in single phase IT equipment loads has resulted in increased distortion and imbalance at the equipment load, the point-of-common-coupling, and even some substation levels. Harmonic distortion and imbalance can have a significant effect on some equipment, especially transformers and motors. Measuring and monitoring these parameters accurately is important when trying to maximize asset usage, prolong the life of the equipment, and prevent catastrophic failures.