Nima Amjady - Department of Electrical Engineering, Semnan University, Semnan, Iran
IEEE Member - Department of Electrical Engineering, Semnan University, Semnan, Iran

An important aspect of power system security is voltage security, which is a result of system heavy loading. In this paper, a novel continuation method with three outstanding features is proposed for voltage security assessment. The proposed continuation method has adaptive step size. For adaptation, a criterion based on rate of voltage drop is applied. This method can monitor voltage security status of power system under various topologies, load levels and generation patterns. Different load scenarios and generation scenarios can be analyzed by this method. Also, the proposed continuation method uses local analysis for evaluation of power system voltage stability after contingency or preventive action. The proposed method has been examined on the test system of New Zealand and Iran's power network. Obtained results confirm the validity of the developed approaches. Also, the most vulnerable buses of these test systems have been sorted by a new ranking function. A discussion about obtained results has been presented.

Voltage Stability, Continuation Method