Improvement of Hydro-thermal Scheduling in the TANESCO power System

 

ABSTRACT

In this thesis, the hydro-thermal planning for Tanzania Electric Supply Company (TANESCO) Power System has been presented. The problem was to determine the Hydro and Thermal generation for a given period of time (24 hours for short term planning in the hourly intervals or one year for long term planning in weekly intervals). The aim of the planning is to keep balance between the production and consumption in a reliable and economical way during the studied period. A mathematical model for all generators has been developed to a linear programming (LP) problem. Linear formulation made it possible to use commercial optimization programs, such as the public domain routine for MATLAB. This optimization problem is subjected to hydrological balance for all hydro power stations (since hydro energy is limited depending on inflow and reservoirs contents capacities). In addition, the constraints in thermal power stations and the load requirements have been taken into account.

The solution of the linear programming gave a detailed schedule with low total operation cost, as the usage of thermal power plants was minimized. Although the generation was mainly from hydro power plants, still the reservoirs contents were maximized, the water elevation levels in all reservoirs was kept high at the end of the planning period. Also the results show that there could be savings of US$ 8,123,235 (1999), US$ 21,041,575 (2000) and US$ 4,049,833 (2001) if the LP solution were used for hydro-thermal scheduling in the TANESCO power system.

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