A general PMU placement approach considering both topology and system aspects of contingencies

چکیده مقاله

In a wide area measurement system, line tripping as well as the following transient and dynamic post-contingency conditions affect the full observability of power systems and possibly the accuracy of the wide area monitoring system. In this paper, a general methodology is presented to solve the phasor measurement unit (PMU) placement problem considering both the system and the topology aspects of disturbances. To do that, the connectivity matrix-based PMU placement problem is firstly formulated in its basic binary integer form to meet the full observability of power systems. Next, the post-disturbance variations in power systems, as the system aspect, are integrated with the conventional placement problem to ensure the more accurate pre- and post-disturbance monitoring of power systems. In addition, the algorithm is developed to achieve the highest possible reliability for single transmission line outages, i.e. N – 1 contingencies, as the topology aspect. Other topology-related issues, including zero injections, PMU channel limitations, and pre-existing measurements are included in the new formulation as well. Since the effects of the two aspects of disturbances on the placement solution are conflicting, and as the magnitude of the system aspect is much stronger than that of topology aspects, compensations are added to balance the conflicting effects by mitigating the strong effect of the system aspect on the overall formulation. Therefore, the proposed methodology will lead to a placement scheme, by which providing the full observability of the system under a high number of single line outages as well as obtaining the more accurate post-disturbance monitoring of power systems are assured. The performance and effectiveness of the proposed methodology are demonstrated in two medium and large test systems.