Optimal Placement of Phasor Measurement Unit in a Power Network for Complete Network Observability

Abstract

One aspect of moving from conventional grid to a Smart Grid is to enhance the reliability and security of grid by real time monitoring of power system that include measuring and keeping control of voltages and currents magnitudes and phasors on all the buses and finding line power flows in a network to prevent the system collapse and blackouts. In this regard Phasor Measurement Unit (PMU) plays a significant role as it is the only device that precisely calculate the voltages and currents (magnitudes and angles) much faster than conventional SCADA technology. To utilize this pinnacle of technology and make it operational in a grid, PMU placement strategic planning is also important. PMUs can be placed on all the buses to get these voltages but due to its high cost it is needless to place PMUs on every bus. This study is based on providing location for optimal placement of PMU with its quantity minimized. Cost effective optimization formulation is also adopted with cases such as, including and excluding the zero injection buses. Algorithm proposed in this study has multiple optimized solutions. System observability redundancy index is being used to further refine these multiple solutions. Case of PMU outage and finding the location of redundant PMU is also presented with its implementation technique that could help to further enhance the reliability of system. Significant results have been achieved by implementing these methods on IEEE 7, 14 and 30 bus system.