Distributed Hybrid Power State Estimation under PMU Sampling Phase Errors

TL;DR

This paper introduces a distributed hybrid power state estimation method that effectively handles PMU sampling phase errors, reducing communication load while maintaining near-optimal accuracy.

Contribution

It proposes a novel distributed algorithm for hybrid power state estimation that accounts for phase errors in PMUs, with minimal communication requirements.

Findings

Performance close to centralized estimates without phase errors

Effective handling of PMU phase errors in distributed setting

Reduced communication burden in the proposed method

Abstract

Phasor measurement units (PMUs) have the advantage of providing direct measurements of power states. However, as the number of PMUs in a power system is limited, the traditional supervisory control and data acquisition (SCADA) system cannot be replaced by the PMU-based system overnight. Therefore, hybrid power state estimation taking advantage of both systems is important. As experiments show that sampling phase errors among PMUs are inevitable in practical deployment, this paper proposes a distributed power state estimation algorithm under PMU phase errors. The proposed distributed algorithm only involves local computations and limited information exchange between neighboring areas, thus alleviating the heavy communication burden compared to the centralized approach. Simulation results show that the performance of the proposed algorithm is very close to that of centralized optimal hybrid state estimates without sampling phase error.