A Harmonic Source Localization Method Based on Critical Admittance Screening With Adjusted Coefficient of Determination

Abstract

The large-scale integration of multiple types of distributed photovoltaics and the increase of nonlinear loads such as residential loads has resulted in significant harmonic voltage distortions in the power system, which is contrary to the high power quality requirements. Harmonic mitigation has received much attention recently, and harmonic contribution evaluation is an important prerequisite. This paper proposes a harmonic source localization method based on critical admittance screening with the adjusted coefficient of determination, in order to determine whether the main contribution to PCC's harmonic voltage distortions is upstream or downstream. The data screening method is based on adjusted coefficients of determination according to the voltage and current data measured at the point of common coupling (PCC). Harmonic source localization is performed with critical admittance. Compared with the traditional harmonic source localization method, data segments with a high degree of linearity in the harmonic voltage and current of the PCC are selected based on the adjusted coefficients of determination. The effect of fluctuations in the background harmonic of the novel power system on the critical admittance is effectively circumvented, which improves the estimation accuracy of the harmonic admittance. In order to verify the performance of the proposed method, several scenarios with different properties of harmonic admittance have been designed in MATLAB. The verification demonstrates the validity and accuracy of the proposed method.