Fault-tolerant placement of phasor measurement units based on control reconfigurability

This paper formulates and solves the problem of placing additional phasor measurement units (PMUs) into a power grid, with focus on enhancing the tolerance to loss of a specified number of PMUs anywhere in the grid under a placement constraint based on a previously defined concept called control reconfigurability. Control reconfigurability imposes a requirement on the minimum Hankel singular value for all anticipated fault scenarios. This requirement causes the placement of PMUs to benefit the use of analytic redundancy in the controlled dynamic grid with respect to anticipated PMU outages, thus enhances the grid resilience. The same principle is applicable to placing additional control devices into the grid. A simple power network model is used to explain the fault-tolerant PMU placement method, and the particle swarm optimization algorithm is employed to minimize the number of additional PMUs placed without violating the required control reconfigurability. The results of placing PMUs for the IEEE 118-bus system are presented.