Identification of harmonic sources by a state estimation technique

This paper describes a reverse power flow procedure to identify the sources of harmonic signals in electric power systems. An electric power network may be subject to harmonic injection due to the presence of nonlinear loads or sources (e.g., rectifiers, inverters). Methods have been reported elsewhere to analyze the propagation of these harmonic signals throughout the network. In this paper, the reverse problem is considered: how does one identify the source (and potentially the type) of harmonic signals. Line and bus data at several points in the network are used with a least squares estimator to calculate the injection spectrum at busses suspected of being harmonic sources. When energy at harmonic frequencies is found to be injected into the network at a bus, that bus is identified as a harmonic source.