Power system simulation and contingency ranking using load bus voltage index

Power system transmission network consists of thousands of transmission lines utilized to enable the system function as required. Components failure in the transmission network accounts for most of the transient instabilities and/or blackouts that have occurred in recent years. Therefore, it is very important to identify the components of the network which are capable of causing blackout in case of failure for proper transmission planning and operations. Various indices have been provided by some authors for contingency analysis in power system Dynamic Security Assessment (DSA) but most of which are computationally demanding. In this paper, a relatively easier index for identifying the critical elements in the transmission network is provided base on the load voltage profile. It is a common experience that when a fault occurs in a power system, the impacts are usually felt at the load centers. Therefore, the load bus voltage profile would provide a true measure of DSA. The index is compared to the generator angle profile to validate its effectiveness and it closely depicts the changes in the rotor angles of the machines. This index is applied and tested on the IEEE 14-Bus test system in MATLAB environment through the use of modelling and simulation.