The Techniques of Handling System Fault about Flexible HVDC Transmission Line

As for the structure and regulating mode of flexible HVDC system is special, the characteristic of the fault of DC transmission line is that the high peak and the fast ascending velocity lead to equipment edge and converter device damage. Besides, it can't take advantage of regulating trigger angle to auto clear fault. So it raises high requirement of protection and handling direct current fault. The paper discusses the structure of flexible HVDC system, the requirement and basic characteristic of control system, the feature of fault and the current situation of research on fault handling of flexible HVDC system domestic and overseas.