LV reticulation and sizing of distribution transformers. Case study areas: Katooke and Omuribiri

Abstract

Electric power utilities are faced with a common challenge of determining the best or optimal transformer radii for their distribution transformers as well as loss reduction within their networks. Inaccurately estimating transformer radii ultimately leads to escalating capital costs, reliability issues and high losses. This project is about coming up optimal distribution transformer zone radii or circuit length for urban and rural areas that will lower losses within these networks. We studied data that had been collected for a month which included the transformers in different areas, the transformer sizes, and the maximum demand as seen on the transformer within that month, the number of customers connected to a particular transformer, the loading factor and the monthly technical losses. From our analysis, it was evident that the highest technical losses are found in areas served by 200kVA transformers. We sampled areas choosing case study areas in Urban and Rural, modelled and simulated their circuits using ReticMaster and studied the graphs generated to determine the scenarios we used for example relieving loads from transformers that were previously overloaded, changing the transformer locations, and upgrading the transformer to see what was the best solution for the urban areas. All this was done while observing mainly the power quality and circuit length. We studied the data for the rural areas and varied the circuit lengths to increase the utilisation factor of the transformers in these areas. We came up with the appropriate transformer zoning radii for the case study areas we had after the different changes were applied to the network.