Sensitivity based procedures for short term augmentation of transmission system in restructured electricity market

Transmission network was recognized as natural monopoly and almost everywhere subject to some kind of regulation in a restructured electricity market. The role of the transmission system is to provide an indiscriminate access for all market players along with an acceptable level of reliability and security. Regulating authorities have to decide about the augmentation investment. As an on going research on forming a robust algorithm for the expansion planning of transmission system in Queensland State, Australia, this paper presents two procedures for the quasi-optimal short-term augmentation of the transmission system. The proposed approaches can accommodate (1) Security of the power delivery to the load points of the transmission system in terms of single line outages (2) Minimization of the transmission system lost load (3) Providing full competitive electricity market for market participants (4) Construction and maintenance costs of transmission augmentation options and (5) Operation efficiency of the transmission grid in their planning frameworks. Each expansion option of the transmission system is evaluated by the aforementioned criteria through designation of a set of indices. The proposed procedures benefits from the concepts of the sensitivity analysis and dynamic programming as well as aggregation method, weighted sum function, in their multi- criteria decision making. The introduced procedures are very promising in case of short term expansion planning of the transmission system. Considering the sensitivity analysis concept employed, in case of long term planning the method is appreciable in smart detection of the suitable zones for expansion. The procedures would be very useful in case of large scale power systems. A 6 bus test system and modified IEEE 30 bus test system are used to validate the effectiveness of the proposed procedures.