In this book, a new method is proposed for the optimal allocation of PMUs in electrical power networks that ensures reliable monitoring of important buses. Unlike the existing methods, the proposed method provides high measurement reliability at important buses by ensuring redundant measurements at those buses. This objective will be achieved by effectively applying the concepts of both direct and indirect observability of important buses. For more efficient deployment of the available PMUs, the effect of zero injection buses is considered in the problem formulation in order to further...