Influence Of Transformer Tap Changer Operation On Voltage Stability

The paper concerns influence of transformer tap changer regulation on secondary voltage level and voltage stability margin of receiving node. At the beginning there are presented general information about voltage stability and tap changer. Voltage value of secondary terminals of transformer can be regulated using tap changer. This regulation also affects the calculation of Thevenin equivalent parameters seen from the secondary terminals. Changes of equivalent parameters cause a change of voltage stability conditions. Simulation studies of this influence for various types of load have been done. Selected simulation results are presented in the paper. At the end there are placed conclusions from the performed studies.