doi:10.16186/j.cnki.1673-9787.2021110108

Received:2022/11/25

Revised:2023/06/03

Published:2024/03/25

Investigation of the shortest path method for small disturbance stability in power systems

WANG Junliang1，CHEN Mengru2，3，LIU Wenjun2

1.State Grid Henan Electric Power Company Electric Power Research Institute，Zhengzhou 450001，Henan，China；2.College of Electrical Engineering，Zhengzhou University，Zhengzhou 450001，Henan，China；3.Zhengzhou Heating Group Co.，Ltd.，Zhengzhou 450001，Henan，China

Abstract: Objectives The small disturbance stability of power systems is affected due to the random variations of grid loads.The power margins of small disturbance stability under different load power growth directions are also different.So it is necessary to determine the most dangerous power increasing direction and its corresponding minimum power margin. Methods The shortest path method based on the geometric modeling analysis had been successfully applied to the static voltage stability analysis of power systems to quickly solve the minimum stability margin.However，the shortest path method had not been used in power angle small disturbance stability analysis of power systems.The dynamic performance boundary of small disturbance stable was formed according to a predetermined damping ratio threshold，and the boundary condition under a non-zero critical eigenvalue was analyzed.By using a virtual observation vector，the analytical expression of the most dangerous power growth direction suitable for small disturbance stability analysis was derived.The calculation model of the short path method for small disturbance stable was established，and the minimum stability margin can be quickly solved by an alternating iteration process. Results the shortest path method was introduced into the small disturbance stability analysis.The convergence properties of the proposed approach were analyzed on the IEEE 68 nodes testing system，and the most dangerous power growth direction after standardization was obtained.This direction provided the participation level of power changes for each node， and the nodes with high participation level played a major role in this power growth direction.Therefore，when arranging system operation plans，it is necessary to pay special attention to the power changes of these nodes.The effectiveness of the algorithm was verified by comparing the trial results with the stability margin of 30 randomly generated power growth directions. Conclusions According to the predetermined damping ratio threshold，a small disturbance stable dynamic performance boundary was formed，an analytical expression for the most dangerous power growth direction was derived，and a small disturbance stable shortest path method calculation model was formed.

Key words:small disturbance stability；damping ratio；minimum power margin；dynamic performance boundary