Electromechanical Transient Simulation of AC-DC Hybrid Power System Considering MMC Model

The electromechanical transient model of flexible DC transmission system adopts the idea of modular modeling, which is mainly composed of AC side module, converter module and DC side module. The converter module is subdivided into control module, equivalent converter module and so on. The relationship between each module and each sub module of converter is established through a certain incidence matrix, so as to form a detailed electromechanical transient model of flexible DC transmission system. Based on the detailed circuit model, a simplified electromechanical transient model suitable for large step size is constructed by quantitatively analyzing the transfer function gain between modules and appropriately simplifying the control module of the converter. The simulation results show that the simplified model proposed in this paper is accurate and can adapt to multi-time scale simulation under different faults.