Harmonic caused transformer heating evaluated by a portable PC-controlled meter

The need for frequent on-site monitoring of harmonic currents both at electric utility ties to industrial and commercial customers and at transformers has increased. If harmonic metering is part of routine measurements, the meter must be easy to use and give a clear record of the measurement. The ability to store the information directly on a computer disk reduces the time and trouble of keeping paper copies in the field. Harmonic heating effects on transformers and a metering technique that is specifically designed for these purposes using a harmonics meter working with an inexpensive notebook or laptop personal computer are discussed.