Locating Multiple Harmonic Sources under the Condition of Unknown Harmonic Impedances

In allusion to the condition that the harmonic impedance is difficult to obtain in actual power grid, a harmonic source location method under unknown harmonic impedance is proposed. In the proposed methodology, the harmonic impedance matrix is obtained by the eigenvalue decomposition of the autocorrelation matrix of the measured samples, and then the signal of each harmonic source current is estimated. Finally, the exact locations of the harmonic sources are identified through mutual information. The effectiveness of the proposed method is verified based on the IEEE 9-bus test system.