Assessment of available transfer capability for practical power systems with margins

This paper describes the assessment of available transfer capability with capacity benefit and transmission reliability margins of practical power systems in a deregulated environment. It is a measure of unutilized capability of a transmission system subjected to wheeling transactions without violating transmission constraints at a given time and load. In this paper, a capacity benefit margin is incorporated by reserving power in five transmission lines. The transmission reliability margin is implemented by making any one of the transmission lines out of order at a time. Optimal generation and cost of generating units have been evaluated using evolutionary programming without violating transmission constraints, which has been tested using the Newton Raphson power flow algorithm. The proposed computation procedure of available transfer capability with margins has been tested and analysed for the IEEE-30 bus system. The solutions obtained are quite encouraging and useful in the present deregulated environment.