An Investigation of Voltage Quality in Low Voltage Electric Power Distribution Network under Normal Operation Mode.

Abstract

With the ever increasing use of power semiconductor devices and information technology (ICT) equipment in the industries, homes and offices voltage quality are gaining meaningful attention to both industry and electric utility level. The lack of voltage quality causes unusually large economic losses all over the world, since voltage quality problem is one of the major power quality disturbances. This paper presents an investigative study on the 11/0.4 kV, low voltage electrical distribution network, aimed at analyzing voltage unbalance and variation problems and recommending an effective method of improving the voltage profile and reducing the voltage unbalance and variation to allowable standard. The network was modelled with the distribution network standard parameters for low voltage distribution network using MATLAB/Simulink Sim Power System tool box. The simulation results with distribution length 0.5 km for balanced three phase load is within the permissible voltage profile of ±5%, reaching the customers, meaning it is admissible for customers use also it was established that an inadmissible poor voltage profile reaching the customers at the network end of distribution network lengths 0.8 km to 5 km which is less than the standard minimum permissible limit of -5%, of nominal voltage value