Considering the increase in power system size and the number of PMUs, the utilization of a computationally efficient yet accurate static state estimator is crucial. The fast-decoupled WLS estimator (FD-WLS) is the most common method employed in industrial applications, thanks to its computational efficiency and ease of implementation. However, it is known that FD-WLS fails in the presence of an ill-conditioned power system, e.g., a power system with high R/X ratio and large difference between measurement error variances. This paper proposes a partitioning strategy for ill-conditioned power systems. The proposed method forms two types of sub-systems, such that one can apply FD-WLS in the type-1 sub-systems, and conventional formulation of WLS should be applied in the type-2 sub-systems. The utilization of the proposed method enables a computational performance comparable to that of FD-WLS and an accuracy comparable to that of the centralized solution.

考虑到电力系统规模和 PMU 数量的增加，使用计算效率高但准确的静态估计器至关重要。快速解耦 WLS 估计器 (FD-WLS) 因其计算效率高且易于实施而成为工业应用中最常用的方法。然而，众所周知，FD-WLS 在存在病态电力系统的情况下会失效，例如，具有高 R/X 比和测量误差方差之间的大差异的电力系统。本文提出了一种病态电力系统的分区策略。所提出的方法形成两种类型的子系统，这样一种可以在类型 1 子系统中应用 FD-WLS，而在类型 2 子系统中应用 WLS 的常规公式。