Optimization of Phasor Measurement Units Placement Under Contingency Using Reliability of Network Components

This study reports an optimization technique to reduce the requirement of phasor measurement units (PMUs) for complete observability under contingency with the use of component reliability. The present methodology secures the data measurement of unreliable and weak-load buses of power network considering hybrid observability for multiphase PMUs installation. The (N - 1), (N - 2) contingency present in the power network requires redundancy for data measurement. The network components with high reliability decrease the contingency of power networks. This reduces the requirement of data measurement redundancy for the network component having high reliability. This article utilizes this relationship between network component reliability and power network contingency to propose the concept of hybrid observability for PMU placement. It combines the concept of complete and redundant observabilities. Power network reliability is determined by incorporating the component reliability of the PMU data measurement system. Weak-load buses responsible for voltage collapse are determined by varying reactive power loading. Furthermore, the proposed weak-load bus closeness criteria (WLCC) and reliability observability criterion (ROC) are utilized for performing ranking of PMU locations using an analytical hierarchical process. These criteria identify the most significant location for initial phases of PMU installation. This strengthens the data measurement of weak-load buses through the most reliable network preventing voltage collapse due to data unavailability even during initial phases of PMU placement. The proposed methodology is illustrated on the IEEE 30- bus and NRPG 246-bus system.