An optimal PMU placement technique for power system observability

Power system state estimation with exclusive utilization of synchronous phasor measurements demands that the system should be completely observable through PMUs only. To have minimum number of PMUs, the PMU placement issue in any network is an optimization problem. A three stage optimal PMU placement method is presented in this paper using network connectivity information. The method initially considers PMU in all buses of the network. Stage I and Stage II of the algorithm iteratively determine (i) less important bus locations from where PMUs are eliminated and (ii) strategically important bus locations where PMUs are retained. Stage III of the algorithm further minimizes the number of PMU using pruning operation. The set of PMUs obtained after Stage III is an optimal set of PMU locations for network observability. Proposed method is further extended for assuring complete observability under single PMU outage cases. Simulation results for IEEE 14-bus, 24-bus, 30-bus, 57-bus, 118-bus and New England 39-bus test systems are presented and compared with the existing techniques. Results show that the proposed method is simple to implement and accurate compared to other existing methods.

► A new topological observability based PMU placement technique is proposed.
► Three stage method is developed using simple network connectivity information.
► Stage I and Stage II finds strategically important buses for PMU placement.
► Stage III finds optimal solution using pruning operation.
► Optimal solution for Single PMU outage is also considered.