A comparative study of VSC-OPF techniques for voltage security improvement and losses reduction

This paper presents and compares three voltage stability constrained optimal power flow (VSC-OPF) techniques for both voltage stability improvement and power losses minimization. The techniques are based on static voltage stability indices which provide important information about the proximity of the system to voltage collapse. The first one is a new concept based on the line voltage collapse proximity indicator (VCPI), the second utilizes the bus voltage stability indicator L-index and the last one focuses on the minimum singular value (MSV) of the power flow Jacobian matrix. The approaches are described in detail and evaluated on the IEEE 14-bus and 30-bus test systems, where their performances are compared under different operating conditions.