Effect of reactive power loading on the stability of power network bus voltage and transmission line


  • Teshome Goa Tella Pan African University Institute for Basic Sciences Technology and Innovation
  • Stanley Simiyu Sitati Electrical and Communications Engineering, Moi University, P.O. Box3900-30100, Eldoret, Kenya
  • George Nyauma Nyakoe Electrical and Electronic Engineering, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya






Bus Loading, Bus and Line Ranking, Ethiopian 230 KV Power Network, Line Stability Index, Modified Voltage Stability Index.


Increased loading results in the instability of bus voltages and power transmission lines, which results in the outage of power transmission lines. For stable operation, finding the maximum loading limit of buses is needed. This paper introduces newly proposed modified voltage stability index (MVSI) and line stability index (Lst) that are used to rank buses and lines, respectively, based on the severity of load contingency. Thus, to account for the effect of inductive load on bus voltage and line stability, only load reactive power is increased up to its maximum stability limit. The MVSI and Lst are determined using Newton Raphson power flow. Buses and lines are then ranked using MVSI and Lst based on the severity of bus loading. The effectiveness of the new stability indices is evaluated against conventional stability indices based on the IEEE-14 bus standard systems and tested on the Ethiopian 230 KV power network. Results show that the proposed indices perform better in ranking buses and lines.





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