Measurement and calculation of harmonics in distribution power system with connected small co-generation facility etan

Abstract

Generation of electrical energy in large conventional plants (thermal, hydro, nuclear) in last ten years worldwide is being supplemented by small generation utilities. Etan is a gas refining facility. Power supply is provided by two turbo generators and each of them can independently cover the consumption of Etan. Etan usually works in insular operation, but it can also work parallel to the distribution system, especially in cases of maintenance of generator units. Etan is connected to the MV distribution power system (10 kV bus in substation 35/10 kV Ivanic Grad) through a 4,5 km long cable. Load in Etan consist mostly of induction motors. Power electronic devices are used for control of motor loads. The working process of the refinery is always the same so the load is not varying with time. It is very important to know the influence of this kind of industrial consumers with distributed generation on power quality. Power quality measurements were performed at three measurement points with the power quality analyzer ION 7650 of company Power Measurement. The aim of this paper is to compare harmonic measurements and calculations at all three measuring points in different operating conditions depending on the production of generator in Etan.