Determination of power transfer capability by incremental changes

Power transfer between areas is a major function of a running electric power system. However, transmission networks have limited capability to transfer power. The objective of this paper is to present how to determine power transfer capability of transmission lines by a practical method. The proposed method is based on computer simulations of various scenarios of operation under incremental power changes at a chosen load bus and a corresponding generator bus. These simulations are performed by power-flow solutions using the Newton-Raphson method. The simulation results provide us indispensable information for successful operations of power systems under various amounts of power transfer. To assess the transfer capability, we first obtain the power-flow solution for the given data by running the power-flow program. For the given data of network, generation, and load, the program obtains the base-case solution. After obtaining power-flow solutions for the base case, we run the program for the scenarios in order to determine power transfer capability of the transmission lines that are of interest. Thus, the power transfer capability is determined. The method we have proposed is computationally efficient and easy to implement. Also, we have developed the power-flow program in a modular way so that it can be expandable with new applications when needed. Consequently, this research work helps system operators and power marketers use the existing transmission lines efficiently.