Harmonic Source Localization Method for Multi-Grid-Connected Inverter Power System Based on Black-Box Model

Abstract

As the main device to connect renewable energy with public grid interface, grid-connected inverter not only has to transport the electrical energy emitted from renewable energy to the grid, but also assumes the important mission of stable operation of power generation system. However, limited to the manufacturer’s confidentiality agreement, the internal structural parameters of the grid-connected inverter cannot be known in the engineering field so that the grid-connected inverter appears a Black-Box. For this case, this paper presents a Black-Box method, using impedance measurement method to obtain the equivalent impedance model of grid-connected inverters, and then the impedance model of the whole system is obtained. On this basis, the positioning of the primary device for the induction of harmonic resonances was done by performing participation analysis of the system. The IEEE14 node case system was used to validate the feasibility of the method.