Area voltage control analysis in transmission systems based on clustering technique

This study proposes a secondary voltage control based on a systematic approach that decomposes a transmission system network into several areas. Network decomposition and pilot buses selection are fundamental in area voltage control. The proposed decomposition approach is hierarchical with two levels of decomposition. The first level is based on the clustering analysis; at this level, the appropriate number of areas is determined. Only several buses (named as control buses) are assigned to each area at this level. The aim of the second level is to assign the remaining buses (named as load buses) to a given area among the already obtained areas in the first level. Buses classification at this level is based on proximity analysis. The control uses reactive power compensation at critical buses, as well as at pilot buses to eliminate voltage violation resulting from disturbances at these buses. For pilot buses selection, a pilot index is proposed. The critical buses are determined based on the sensitivity factors. The IEEE 39-bus and IEEE 118-bus are used to illustrate the performance of the proposed approach.