Investigation of P-V and V-Q based optimization methods for voltage and reactive power analysis

The management of voltage and reactive power control sources considering the voltage stability is a challenging issue for secure operation of power systems. Generally the analysis of the stability margin is performed using P-V and V-Q based approaches. This paper initially investigates the main characteristics of these two stability analysis methods. Regarding these two approaches, two formulations for the maximization of loading factor and the maximization of effective reactive power reserve are studied. Both of them can be considered as preventive actions. Other formulations are presented for contingency analysis and evaluation of required corrective actions. The proposed formulations benefit from: (i) the detailed modeling of generators reactive power limits, (ii) the generators mode switch between constant terminal voltage and constant reactive power output with complementarity constraints and (iii) the distributed slack bus model for the compensation of active power imbalances. The effectiveness of the proposed formulations as well as the advantages and drawbacks of these two stability analysis approaches are discussed more in depth using three test systems.