The invention discloses a photovoltaic grid-connected multi-
inverter system resonance observation method based on node mapping, comprising three parts: detecting the
resonance frequency, determining aresonance center and evaluating the participation degree of each element. A network node
admittance matrix is constructed based on a multi-
inverter system node mapping model; feature values and feature vectors of the matrix are calculated, an approximate
singular matrix is searched, and the reciprocals of the feature values and the
frequency spectrum curve of frequencies are output; and the participation factor of each node under each resonant frequency is calculated, the position of the
resonance center is determined, the resonance sensitivity of the nodes is compared, the sensitivity of each element is analyzed, and the resonance participation degree of each element is evaluated. According to the method, comprehensive resonance condition analysis can be carried out on a photovoltaic grid-connected multi-
inverter system, the
harmonic resonance analysis efficiency of the system is improved, a basis can be provided for the topological design and element
type selection of a photovoltaicpower
station, and a foundation can be laid for the research of a resonance suppression strategy.