Estimation, control and prediction of voltage level and stability at receiving node

The paper presents issues of receiving node voltage stability. Voltage level is related to voltage stability. However, this value is not always a good indicator of distance to the stability limit. Discrepancies may occur especially when voltage regulation is performed. Such regulation causes changes of voltage level and voltage stability conditions. Thus, it seems reasonable to observe and predict voltage stability margin. In the paper basic information about the voltage stability considered as a local problem and voltage regulation influence on stability conditions are presented. Method of stability conditions calculation using local information and including of this parameter in the regulation processes are proposed. Stability margin calculation is based on on-line local measurements and the range of change of Thevenin model parameters determined in off-line studies. During simulations two models were used: IEEE 14-bus test system (ATP-EMTP) and node model containing voltage regulation (Matlab).