Optimal re-dispatch of generating units ensuring small signal stability

• Published in: IET generation, transmission & distribution Vol. 14; no. 18; pp. 3692 - 3701
• Main Authors: Hamidreza Adeli, Seyed, Rabiee, Abdorreza, Taghipour Boroujeni, Samad
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 18.09.2020
• Subjects: generators scheduling; IEEE 69‐bus 16‐machine test systems; load flow; modal analysis; multiple URA generators; optimal power flow problem; optimal re‐dispatch; power generation dispatch; power generation scheduling; power generators; power grids; power system; power system control; power system stability; rescheduling program; Research Article; re‐dispatch algorithm; re‐scheduling method; rotors; signal stability constraint; single URA generators; SSS; transmission lines; unstable rotor angle; voltage stability margin; power system stability; rotors; re-scheduling method; power system; generators scheduling; unstable rotor angle; IEEE 69-bus 16-machine test systems; modal analysis; signal stability constraint; transmission lines; rescheduling program; power generation scheduling; power generation dispatch; SSS; power generators; optimal re-dispatch; re-dispatch algorithm; optimal power flow problem; voltage stability margin; power system control; multiple URA generators; power grids; single URA generators; load flow
• ISSN: 1751-8687; 1751-8695; 1751-8695
• DOI: 10.1049/iet-gtd.2019.1319

This study presents a new re-scheduling method for generating units in the form of optimal power flow (OPF) problem, considering small signal stability (SSS) constraint of power system in normal operation and N−1 contingency of transmission lines outage. In base case, total operation cost is minimized, considering voltage stability margin and N−1 line contingency. The SSS of system is studied by using modal analysis. In case of unstable modes in the generator(s) rotor angle, the generators scheduling should be re-dispatched. Using modal analysis and sensitivity matrix, the generators are divided into three groups: increasing power generators, decreasing power generators, and unchanged power generators. In order to increase the accuracy of re-scheduling program, two new technical and economic indexes are introduced. The output power of the candidate generators is increased/decreased based on the indexes to stabilize generator(s) with unstable rotor angle (URA). The salient feature of proposed method is its capability on stabilizing system with one or more URA generators with minimum changes in base case OPF results. The Validity of proposed method is studied on IEEE 39-bus 10-machine, and IEEE 69-bus 16-machine test systems. The obtained results verify effectiveness of proposed re-dispatch algorithm in case of single or multiple URA generator(s).