Investigation of a Critical Voltage Proximity Index at Distribution Level

A developed mathematical index is investigated in this paper. The index is applied on distribution test systems, and verified for its compatibility through the use of a tap changing transformer 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.