Study of power quality with changing customer loads in an urban distribution network

Power quality is one of the most significant current discussions in electric energy distribution systems. The issue of harmonics has been a controversial and much disputed subject within the field of power quality. Harmonic current originates from all types of nonlinear loads. This paper attempts to show the impacts of rapidly increasing share of nonlinear loads on harmonic distortion of urban distribution feeders. The recommendations of IEEE Std. 519-1992 and Bangladesh Grid Code are considered carefully. Simulations have been carried out to find out how far the existing distribution system can accommodate non-linear loads. Results show that though the connected load is not hampering power quality of test distribution at present, an increase of nonlinear load share above 30% would cause Total Harmonic Distortion (THD) go beyond tolerable limit and result in poor power quality.