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

Maintaining network stability and encouraging generation companies to get involved in stability-maintaining objective are major concerns of an Independent System Operator (ISO) in a 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. However, utilizing the methods that improve the performance of excitation system imposes cost on generation companies. This paper proposes a motivation mechanism for enhancing transient stability that encourages generation companies to improve performance of excitation system. In this mechanism, besides excitation system response improving methods, a transient stability constrained optimal power flow is solved in order to ensure maintaining transient stability under different contingencies. A 4-bus test system, an IEEE 14-bus test system, and an IEEE 118-bus test system are used to illustrate the 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. (C) 2019 Sharif University of Technology. All rights reserved.