Research And Application Of Key Technologies For Relay Protection Optimization Of Tianwan Million Nuclear Power Units

Nuclear power plants are the important part of Chinese energy.The operation and safety of nuclear power plants are very important obviously.The paper focuses on the research and application of key technologies for relay protection optimization of Tianwan Million Nuclear Power Plant,analyses the defects,unqualified items and improvement measures of the secondary functions for protection of Tianwan Nuclear Power Plant.A feasible optimization scheme is proposed for the problems that have occurred during the operation of the relay protection device.It provides practical experience for solving the anti-interference problem of transformer microcomputer protection,related circuit design of relay protection and component selection,and ensures the safe and stable operation of the units and equipment.The paper has important engineering application value for the safe operation of typical nuclear power plants in China.This paper firstly analyzes the operational defects and shortcomings of the original relay protection of the Russian Tianwan Nuclear Power Plant,proposes the key technologies to improve the strategy for the defects and deficiencies,establishes the dual protection measures for the micro-machine protection channel and optimizes the operation and maintenance devices.This paper analyzes the defects of 500 kV bus differential protection and breaker failure protection,and introduces the optimization measures of differential protection and failure protection in detail.Then this paper reconstructs the Russian-supplying Tianwan nuclear power plant transformation group,and analyzes its optimization effect in detail,from the transformer differential protection,generator loss-of-magnetism protection,generator stator grounding protection,protection dualization,composite voltage blocking over-current protection,etc.Finally,the main faults of the Russian-supplied excitation system of the Tianwan Nuclear Power Plant are listed,in view of the problems existing in the original Russian excitation system.The optimized excitation adjustment device NES6131 is described in detail,the pros and cons between the original Russian equipment and similar products at home and abroad are comprehensively compared.