A New Method for Prediction of Static and Dynamic Voltage Collapse Using Node Parameters in Large Power Networks

Power networks are operating under highly stressed conditions during peak load demands. A power system, under such stress, can be exposed to slow or sudden voltage drops and ultimately lead to the form of voltage collapse. This paper proposes new node voltage stability index (NNVSI) for predicting the node static and dynamic voltage collapse incidences. The new voltage stability index is applicable for an n-bus system based on the node voltages and network admittance matrix. The NNVSI was tested on the IEEE New England test system. The applicability is attested by comparing with other techniques namely the power flow Jacobian singular value, power transfer stability index (PTSI) and modified voltage stability index (MVSI). The indices were evaluated under gradual and sever load power changes at critical load node. The results show that the proposed index effectively predicts the static and dynamic voltage stability collapse points with less computational time. The performance of the new index has been also verified by the time domain voltage responses and the consecutive load flow solutions until the Jacobian matrix become singular. The static analysis and time simulations are implemented in MATLAB environment.