Determination of Total Harmonic Distortion (THD) on a 33kv Distribution Network: A Case Study of Island Business District

Abstract

Distribution Line Network harmonic investigation has become an important issue in electric power systems since the increased use of power electronic devices and equipment sensitive to harmonics, which in turn, has increased the number of adverse harmonic-related events. Power quality problem and the means of keeping it under control is a growing concern. Due to the connection of nonlinear loads in a 33kV distribution network, power quality issues have been raised and have resulted to widespread waveform distortion. This paper makes use of the Busbar voltage solutions obtained from a power flow study on the Eko Electricity Distribution Company's 33kV network and they are used as the base data for the harmonic analysis. A distribution line model was formulated. MATLAB/Simulink was used to simulate this modelled network for each distribution lines of the power system network considered. This simulation was achieved through the application of sending and receiving end busbar voltages already obtained from the power flow study. The harmonics observed on each distribution line at various scenarios of load/feeder restoration and their characteristic impedance magnitudes/frequency are all presented. Necessary discussions on the harmonic results are also presented.