Research on Impedance Modeling Technology of Multi-Machine Grid-Connected Inverters Considering Frequency Coupling and Line Models

With the rapid development of renewable energy, multi-machine grid-connected inverters (MMGCI) have become an indispensable component of modern power systems. This paper conducts an in-depth study on the impedance modeling technology of multi-machine grid-connected inverters and proposes a new modeling method that comprehensively considers the effects of frequency coupling and line models on the dynamic characteristics of the system. By exploring the working principles of multi-machine grid-connected inverters, the frequency coupling mechanism is introduced, and the comprehensive characteristics of the actual system are modeled in combination with the line model. Finally, the obtained impedance model is verified through simulation. The simulation results show that, compared to traditional models, the new modeling method significantly improves accuracy and adaptability.