A Non-Synchronous Harmonic State Estimation Strategy Based on Redundant Virtual Measurements

Existing harmonic state estimation methods are mostly based on synchronized measurement data. However, due to various technical and economic constraints, the coverage of synchronized measurement devices in power grids is relatively low. In contrast, the penetration rate of power quality online monitoring systems (PQMS) is much higher, but the monitoring data from different nodes are not synchronized. To address this issue, a non-synchronous harmonic state estimation strategy based on redundant virtual measurements is proposed. The method introduces compensated phases to the non-synchronous monitoring data and constructs a synchronized nonlinear harmonic state estimation model. A non-synchronous phase compensation method based on redundant virtual measurements is also proposed to improve the observability of the harmonic state across the entire grid.