Analysis of Asynchronous Transient Stability Mechanism and Research on Influence Factors of DC Modulation Effect of Sichuan Power Grid

This paper studies the typical asynchronous interconnected formed by power Sichuan-Chongqing which is compose of Chongqing power grid through the AC lines and East China, Central China and North China interconnections through DC lines based on Sichuan power grid, analyzes the transient stability operation mechanism of the asynchronous power grid, and discusses the relationship between the excess or insufficient active power rate and the frequency overrun. At the same time, it introduces the classification of DC modulation and the factors that have influence on the effect of DC modulation. Then it introduces the principle and structure diagram of dual-end frequency modulation and DC power increase/decrease in detail. Further more, it studies the relationship between the coordination of reactive power and the parameter value of the modulator, which will have an impact on the effect of DC modulation.