Harmonic distortion correction using active power line conditioners

Abstract

Harmonic distortion of a voltage waveform on a local distribution system may have many effects, such as: protective device malfunctions, medical equipment failures, and increased noise generation and bearing wear of rotating equipment. In the past these effects have been tolerated. Advances in semiconductor technology in the past two decades have produced devices that can handle large amounts of power efficiently and safely. These advances have led to an increased number of loads that contribute to the bus voltage distortion. These same advances that have made the distortion problem worse also have given rise to devices that can be used to actively correct the problem. Active Power Line Conditioners (APLC's) use voltage or current converters to improve harmonic distortion on local buses. APLCVs use information from current or power sensors that are spread throughout the distribution system in order to correct the voltage waveform distortion. These sensors are difficult and costly to install. This thesis presents an APLC that produces its distortion canceling signal using only bus voltage information, thus reducing the distribution sample points to one. The LabVIEW graphical programming language is used for sampling and control of the APLC