Providing transient stability by excitation system response improvement methods through long-term contracts

Maintaining network stability and encouraging generation companies to involve in stability maintaining are major concerns of independent system operator (ISO) in deregulated power system. Excitation system of synchronous generators is effective and well-known equipment which has a significant effect on network stability. Therefore, improving performance of this system can enhance network stability. But utilizing of the methods, which improve performance of excitation system, imposes cost on generation companies. This paper proposes a motivation mechanism for enhancing transient stability which encourages generation companies to improve performance of excitation system. In this mechanism beside excitation system response improving methods, a transient stability constrained optimal power flow is solved in order to ensure maintaining transient stability in different contingencies. A 4-buses test system, the IEEE 14-buses test system, and the IEEE 118-buses test system are used to illustrate effectiveness of the proposed mechanism. Implementation results show that the proposed mechanism not only provides required transient stability margin with minimum operation cost, but also does not restrict generators production capability.