Minimization of power losses in distribution system through HVDS concepts

In India there is a need to improve the quality and economy of the electricity distribution process which has increased varying from year to year. In overhead networks, the limiting factor to load carrying capacity is generally the voltage reduction. To improve the quality of supply, one of the recommendations is the implementation of "Single phase HT distribution system with small capacity single phase transformers. Under this system HT line is extended up to or as near the load as possible and to erect small capacity distribution transformers i.e. 25 KVA and to extend supply to the consumer through a short length of LT lines, preferably insulated overhead cable (Aerial Bunched Cables) system. Losses in the existing system are as high as 30%(approx.). In the existing Low Voltage Distribution System where the multiple loads are fed from a single large capacity transformer and the loads are not uniform from the Starting bus to the Tail End bus and also the loads have low power factor and low load factor. Further, load density is low due to dispersal of loads. The existing 11 KV distribution KOVUR-SS consists of 30 distribution transformer with lengthy L. T Lines. In this system, the losses are high; voltage profile and reliability are unsatisfactory. In this, the existing Low Voltage Distribution system of KOVUR Sub-Station Layout has been simulated with the help of ELECTRICAL TRANSIENT ANALYSIS PROGRAM (E-TAP) software and the real time losses have been identified in order to improve the stability of the system and getting same voltage in starting bus as well as in the ending bus. The LVDS Layout has been restructured as HVDS and has been introduced with small capacity distribution transformers. Results of the load flow analysis shows a significant reduction of line losses which reduced to as low as 5%.