Improving the power-quality is one of the important measures for operating the electrical-distribution networks. Motor driven-loads supplied from distribution-networks can cause severe voltage-sag during motors' acceleration. In this research, the application of series-and shunt-compensation for improving the voltage-profile during steady-state and motor-startup is studied by simulation and checked experimentally. The obtained results indicate that series-capacitors provide an adaptive improvement to the voltage-profile being related to the load reactive-power demand while the shunt-capacitors provide a nearly constant-voltage improvement irrespective of the load-level. With motor acceleration, the series-capacitor reduces the voltage-sag during motor-starting and the acceleration-time by up to 19.37% and 54.7%, respectively when compared with motor-starting without capacitors. To the authors' knowledge, the present-paper is the first to successfully reduce the voltage-sag to its acceptable levels during the motor's starting period using series-capacitor. On the other hand, shunt-capacitors show no significant improvement of the voltage during the starting-period of the motor. Finally, a case study of a real distribution-network (Karot line) in Egypt loaded by several water-pumps driven by induction-motors is investigated using ETAP-package. Performance of the line under the influence of series-and shunt-compensation is studied and the obtained simulation results conform to those obtained experimentally in the laboratory.
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