Abstract:Based on the rapid development of renewable energy generation technology, the proportion of renewable energy generation is increasing year by year. And renewable energy will introduce harmonics into power system after being integrated through inverters. When renewable energy is linked to the grid on a large scale, the harmonic content is abundant and there may be a possible risk of resonant overvoltage. Firstly, a harmonic mathematical model is established for photovoltaic grid connected system. Then, harmonic analysis on a single renewable energy site access system is carried out, and the impact of inverter parameters, line parameters, and grid equivalent impedance on system voltage after resonance is analyzed. And harmonic analysis on a variety of renewable energy access systems is also carried out to investigate the resonance variation pattern of renewable energy access at various scales and its impact on system voltage.