Observability analysis of PMU placement: Multiple-solution studies

This paper considers PMU placement by evaluating network observability and state estimation accuracy. The paper points out that multiple solutions of Binary Integer Linear Programming (BILP) in observability analysis are overlooked by researchers and illustrates why this deserves our attention. Branch-Expansion Method (BEM) is used to retrieve all possible solutions. This new method is based on an existing solution from BILP and is easy to implement. After having all these different solutions in the case studies, accuracy in state estimation is evaluated. This then provides guidance in the PMU deployment. IEEE 14-bus system and New England 39 bus system are studied to illustrate the idea of this paper.