Risk Based PMU Placement in Electrical Power Systems Using Firefly Algorithm

PMUs can measure real time voltage amplitude and phase angle as compare to slack bus at itself and neighboring buses which are linked to it. This paper proposes a new risk based PMUs placement model in electrical power systems for annual scheduling time interval with regard to single and double credible contingencies of PMUs from synchrophasors system. Objective function for this optimization problem is defined minimization the sum of PMUs numbers and network unobservability risk index while problem constraints guarantee network full observability and optimal network unobservability risk value respectively under normal and after PMUs single credible contingencies of synchrophasors system conditions. Power network unobservability risk index relies on three main factors such as buses importance, forced outages probability of PMUs, depth of bus and network unobservability after PMUs failures which added non-linear properties to aforementioned optimization problem. Firefly algorithm is applied to solve proposed model. Finally, to evaluate performance and effectiveness of risk based PMUs placement model simulation studies are applied on 14-bus and 30-bus IEEE test typical power system. Sensitivity analysis has been performed by change in some important factor of network unobservability risk index such as PMUs availability.

Keywords:

Phasor Measurement Units (PMUs) , System Unobservability Risk Index , Bus Importance , Depth of Unobservability , Probability of Unobservability , Firefly Algorithm.