High crest factor loads on UPS systems

Abstract

Some of the problems that can be caused by high crest factor (HCF) in UPSs (uninterruptible power supply systems) are outlined. It is noted that the effect of a high crest factor load on a UPS will depend on the technique used to generate the UPS output voltage. Ways to avoid problems with HCF are discussed, including load balancing, the use of a fully rated neutral conductor, the measurement of voltages at the UPS and the load, the correct rating of the UPS, and the use of a third-harmonic filter.<>