A Stability Analysis and Quantitative Evaluation Method for Hybrid Transmission Systems

In China, the implementation of DC system engineering led to a hybrid transmission system with north-south transmission “AC to DC” conversion, which can solve the problem of limited transmission capacity caused by scarce transmission cross-section, but may have an impact on the safety and stability of the power grid. Therefore, static safety analysis methods are needed to verify the safety of the transmission system. However, in the context of the large power grid, facing a large amount of data, it is difficult to analyze the key factors that affect the stability of the AC system due to the connection of the DC system. The Copula entropy method, as a mature analysis method, can be used to analyze correlated data in a system in a large batch of data. This article considers the static characteristics of DC transmission systems and establishes suitable static analysis models and electromagnetic transient simulation models for research. Meanwhile, based on the Copula entropy method, the key factors affecting the operational characteristics of the AC system in the DC transmission system were extracted, and a static safety analysis method and evaluation index suitable for complex hybrid systems were proposed.