Distributed Hybrid Power State Estimation under PMU Sampling Phase Errors

Abstract

Phasor measurement units (PMUs) have the advan- tage 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, hy- brid power state estimation taking advantage of both systems is im- portant. 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 er- rors. The proposed distributed algorithm only involves local com- putations and limited information exchange between neighboring areas, thus alleviating the heavy communication burden compared to the centralized approach. Simulation results show that the per- formance of the proposed algorithm is very close to that of central- ized optimal hybrid state estimates without sampling phase error.