Dominant Harmonic Sources Identification Considering Variation Characteristics of Impedances under Multiple Network Operation States

Harmonic sources in new power systems are characterized by wide distribution and interactive coupling. Due to the negative impact of harmonic measurement distortion and multi-source interaction, the existing methods are prone to misjudge the dominant harmonic source. To solve this problem, this paper proposes a dominant harmonic source identification method based on impedance variation characteristics under multiple network operation states. This method firstly changes network operation states by switching passive components such as reactive power compensation devices. Then the average rate of change of the equivalent harmonic impedance at the point of common connection under different network operation states is calculated, and thus the dominant harmonic source identification is carried out according to the level of impedance variations. Through simulation data and field case analysis, the results show that the proposed method can identify the dominant harmonic sources more accurately than the existing methods.