Harmonic Source Location at the Point of Common Coupling Based on the Nonlinearity Index of Load

Harmonic source quantitative location can not simply be achieved by the severity of load harmonic distortion at the point of common coupling (PCC) because the tested harmonic at PCC contains the background harmonic and the harmonic of given customer emission. Harmonics in distribution system are caused mainly by nonlinear loads. In view of this, a harmonic location method based on the nonlinearity index (NLI) of loads is proposed. In this method, the real parameters of loads are calculated by using the time domain model, and the linear parameters of loads are obtained by removing residual error. The nonlinearity index is calculated to evaluate the harmonic emission level. The simulation and the practical engineering results indicate that the proposed method is valid and feasible.