Analysis Of Blocking Factors And Preventive Measures For Yunguang HVDC System

As the first UHVDC project in the world,the 800 kV DC transmission system is the first time equipment,control and protection system,which is the first application in China and even in the world.The new system,new equipment and new technology have not been tested for long time and heavy load,and there are many unknown factors and uncertainties in safe and stable operation.As soon as possible to master the system operation rules,"temperament",to find out the equipment measures,can greatly improve the level of operation and maintenance,to achieve the first UHV DC system ground down the tube well".The project is in operation experience over the years in the HVDC transmission system,analyzing the causes of various faults,on-site inspection of drawings,equipment maintenance manual and hardware design reports,combing all cause + 800 kV Yunnan Guangdong DC transmission system locking factors,treatment process,criterion,detailed analysis of the action signal the various factors,and put forward the corresponding prevention and control measures.The main research contents are divided into three parts:In the first part,the configuration of AC and DC protection in Suidong Station is studied,and the protection scope,function and action consequence of each protection which will lead to blockade are given in detail.In the second part,all the factors causing the blockade of Yunnan-Guangzhou DC are sorted out and the corresponding preventive and control measures are put forward,including the fault of main equipment,the fault of DC control and protection system and the abnormal of auxiliary system.In the third part,on the basis of comprehensive and detailed analysis of the above problems,combined with the blocking accidents in the history of Yunnan-Guangzhou DC,the control and protection logic of valve group bypass switch is reformed,and an effective reform scheme is put forward to effectively avoid blocking caused by multiple jumps of valve group bypass switch.In summary,on the basis of analyzing the blocking factors and their action reasons,this paper puts forward corresponding pre-control measures to improve the reliability of equipment operation,reduce the number of valve sets,unipolar and bipolar blocking in Yunnan-Guangzhou HVDC transmission system,and ensure the safe and stable operation of Yunnan-Guangzhou HVDC as far as possible.