VSC-OPF based on line voltage indices for power system losses minimization and voltage stability improvement

Power system optimization while improving system security and performance has become a major challenge in power systems planning and operation. As modern systems are being operated under heavily stressed conditions with reduced stability margins, incorporation of voltage stability criteria in the operation of power systems has become necessary. This paper presents a novel voltage stability constrained optimal power flow approach based on the line voltage stability indices. The objective of the new VSC-OPF is to add the voltage collapse proximity indicator (VCPI) into the OPF constraints to simultaneously minimize power losses and improve voltage stability. The proposed approach has been evaluated and compared with conventional OPF on the IEEE 30-bus test system under different cases. The simulation results are promising and demonstrate the effectiveness of the proposed VSC-OPF using the line voltage stability index.