"HARMONICS" a recent entrant to power quality problem in uninterruptible power supply

The major source of power quality at customers site is uninterruptible power supply (UPS) as viewed by utility. This equipment draws large amount of harmonic current from supply causing distortion in voltage. In addition they also draw current at low power factor. Hence it has become extremely important to control the supply from the ill effects caused by UPS since they produce a significant harmonics, which leads to additional loading resulting in the raise of temperature. The basic objective of this study was to collect data on existing levels of harmonic current, voltage, power factor in UPS, which will help utilities to deal with power quality problems. The utilities were Karnataka Electricity Board (KEB) and Diesel power supply Data collected during these studies have been analyzed so that a filter can be designed to reduce the harmonic pollution caused. Work is in progress for the designing the same.