Multi-criteria integrated voltage stability index for weak buses identification

Abstract

How to identify the weak buses comprehensively and practically in power system voltage stability analysis is an important issue, and is posing great interests to the power engineers. In this paper, a multi-criteria integrated voltage stability index was proposed for weak buses identification. Firstly, the bus voltage change index and reactive power margins, which were determined by P-V curve and Q-V curve, respectively, were employed to form the required data set involving the corresponding bus voltage margin and reactive power margin information. An overall and practical evaluation method called as ideal point method was then proposed to integrate the two aforementioned voltage stability indices with certain weight. By tuning the corresponding weight coefficients, the decision-making reflecting the preference of power engineer could be made. Finally the case studies on the 10-machine 39-bus New England test system as benchmark were carried out to demonstrate the validity and effectiveness of the proposed method.