Power | Telecom |
Transport |
Others
Management of sub-transmission and distribution system in power utilities
Network Analysis for technical loss reductions and Network planning
Once the Electrical database of the network is imported from the GIS/AM/FM into an Electrical Engineering Analysis platform, the resulting network model can be subjected to various analysis runs for carrying out studies that will be of interest to a distribution engineer. These will include the following but not limited to,
 Fig. 6 Figures 6 and 7 show the view of the typical voltage drop analysis and capacitor placement in representative network:  Fig. 7 Real time and historical demand and energy data at source and also at consumer end will also be needed to simulate the network loading conditions. The source for the historical data will usually be the log registers maintained at the distribution sub-stations. Some data augmentation may have to be done either by installing logging type meters at strategic points in the network or by taking one time current measurement using tong-testers. In the short term, the results of the analysis would be used for estimation of base level technical losses, and for segregating the total unaccounted losses of the system, available from the energy balance into technical losses and the non-technical i.e. commercial losses (occurring mainly due to faulty /tampered metered supplies, due to the illegal connections, due to power delivery at flat rate to the subsidised category of consumers). Besides, extrapolation of the results of the analysis of a sample low voltage (0.4 kV) network for the complete low voltage network will also be done. The technical power loss reduction will be accomplished by the following measures:
In the long-term, due to the need to identify and predict the customer demands that will decide the system loading conditions prevailing in future, use of other techniques like the trend analysis of load growth and load forecasting will be required. The process of load forecasting based on the trend analysis of past load growth, though complex, is invaluable in optimising the planning approach for the network expansion on a long-term basis. As stated above, having a geographical reference for the network will provide necessary information on land use pattern for planning optimum expansion of network and for setting up of new facilities. The spatial load forecast method, which divides the total area into number of small areas, with the specific growth rates and the load characteristics applied to each small area, is the ideal method for optimal planning of the distribution system of the area. For optimal location of new sub-stations and augmentation of the existing facilities, several alternatives, subject to their meeting the agreed planning criteria, will be evaluated on basis of the capital cost of equipment and work and net worth present worth of the energy losses over the total horizon period. The plan objective will be the minimization of losses while maximizing the net benefit i.e., the present worth of loss reduction less the annual cost of capital investment. The cost estimates will be based on the prevailing market rates for each item of equipment and work. The load flow analysis study would provide a graphical display of the results of the network strengthening measures described above in meeting the specified requirements, as well as the losses for the various alternatives. The user can take decision, looking at the graphical display provided by the analysis software, for utilising the different network strengthening measures at his disposal, available as ‘edit’, ‘network sketching’ and specific ‘network optimisation’ features in the software. |