Global Journal of Technology and Optimization

Critical Voltage Proximity Index Investigation For Transmission Systems

Abstract

Hassan Nouri, Dan Micu

A developed mathematical critical voltage proximity index is investigated in this paper. Mathematical description of the index is provided. Background theory on established statistical indices, as well as mathematical indices recently developed, are presented, highlighting the successful application of the index in distribution systems, featuring low X/R ratio values, and the need for investigation of the index at transmission level. The index is applied on a transmission test system and verified for its compatibility through the use of tap changing transformers as voltage sag mitigation scheme. Three induction motor load variation scenarios are investigated in order to establish the effectiveness and accuracy of the index. The development of a multiple tap changing controller scheme within PSCAD software is also described. The index improves the power quality of a system, through providing a tool for on-line voltage sag mitigation, featuring multiple potential applications.