Analysis of harmonic pollution on power distribution systems

Lower-order harmonics (180 Hz to 2000 Hz) generated by nonlinear loads, such as uninterruptible power supply (UPS) units, adjustable frequency drives, computers, etc., cause harmonic pollution. This pollution can cause problems within power distribution systems that can range from the malfunction of protective devices to the physical damage of power system components and loads. The authors present ideas on how to design an industrial power system with the sources of harmonics in mind and, using computer analysis, to determine whether a harmonic problem may exist. They provide information that can be used to measure an existing electrical system that exhibits evidence of a harmonic problem. The use of tools such as commercial harmonic analysis programs and the IEEE standards is suggested to simplify the analysis of systems and provide guidelines that indicate where problems may lie.<>