Research on equivalent modeling of VSC-HVDC grid-connected system for large-scale offshore wind power energy

Offshore wind generation energy is developed rapidly, especially the urgent need to build a 10 million kilowatt Offshore wind generation base. The transmission and grid connection of large offshore wind generation has become an urgent problem to be studied and solved. When offshore wind generations are far offshore, the cost of long-distance AC transmission is higher than that of DC transmission. At the same time, the charging power of inductance and capacitor is too large, reactive power compensation is required, and the quality of incoming power is reduced. VSC-HVDC transmission technology not only has the characteristics of traditional DC transmission technology (including long-distance transmission), but also has many advantages, such as no commutation failure, reactive and active power decoupling control, power supply to passive network and so on. Therefore, VSC-HVDC transmission technology will become one of the development trends of large number of offshore wind generation transmission. It is urgent to carry out the research on control and protection technology of large number of offshore VSC-HVDC grid connected transmission. Provide technical support for the development and operation of large offshore wind generation in eastern coastal areas such as Shandong and Jiangsu, promote the development of multi VSC-HVDC parallel transmission technology, improve the manufacturing technology level of offshore wind generation equipment, and promote the healthy development of offshore wind generation. Aiming at the technical requirements of VSCHVDC grid connected transmission in large offshore wind generation ten million kW base, this paper studies how to establish an accurate electromagnetic transient model of wind turbine based on a large number of practical tests and offshore wind turbine data. By selecting appropriate aggregation variables and aggregation algorithms, the necessity of proposing electromagnetic transient equivalent modeling method of wind generation is analyzed. It provides a research basis for analyzing the technical requirements of modeling and simulation development of tens of thousands of kW offshore wind generation cluster and revealing the interaction of fault characteristics between large offshore wind energy power base and power system grid under different faults.