Dominant harmonic source identification approach based on multi-criteria collaboration: A practical case study of a 500 kV meshed transmission network

Transmission networks face increasingly severe harmonic distortion challenges originating from extensively distributed power-electronic-type harmonic sources and frequent harmonic resonances. Traditional techniques for harmonic source tracing are primarily designed for distribution networks and rely on specific prior assumptions such as a single-source scenario, distinct grid-customer boundary, and stable impedance. However, transmission networks typically adopt meshed topologies, which exhibit significant differences that violate the required assumptions, rendering classical methods ineffective. To tackle the issue, this article develops a multi-criteria collaboration approach for dominant harmonic source (DHS) identification using a practical 500 kV meshed transmission network as a case study. Several criteria are introduced to portray the distinctions in harmonic voltage, power flow, and impedance properties of the meshed transmission network under different locations of DHS. A framework integrating monitoring data and mechanism modeling is constructed for multi-criteria deduction, and the outcomes derived from data and model are then subjected to consistency verification to locate the DHS. The practical case study demonstrates that the proposed approach mitigates the one-sidedness of single-criterion evaluation and overcomes the limitations under complex scenarios such as meshed topologies and multi-source harmonic coupling. Compared with conventional methods, it achieves more accurate identification of the DHS and exhibits superior adaptability in meshed transmission networks.