Structural Design And Characteristic Test Of 10kV Permanent Magnet Phase-controlled Vacuum Circuit Breaker

Switching equipment plays an important role in opening and closing,controlling and protecting power grid and power equipment in all links of power generation,transmission and distribution in the whole power system.Its main components are circuit breakers,isolation and load switches,transformers,bus and protection devices.As a core component,the development level of circuit breaker directly reflects the development level of switching equipment.The opening and closing of the circuit breaker is essentially the contact and separation of the dynamic and static contacts in the circuit breaker.The arc generated by the breaking of the contact under high voltage will cause great damage to the contact,delay the breaking time and even cause adverse events such as grade rejection.Arc extinguishing medium has the function of extinguishing arcs.In the field of high pressure,sulfur hexafluoride has obvious advantages as arc extinguishing medium,but in the field of medium pressure,vacuum arc extinguishing accounts for the absolute proportion of 10 k V.The operation mechanism of vacuum circuit breaker equipped with permanent magnet mechanism has good performance in reliability and controllability,which is most beneficial to the application and realization of phase control technology.It is of great significance to study the overall structure principle of the phased vacuum circuit breaker and the design method of permanent magnet mechanism based on the phase control technology for improving the construction level of China’s smart power grid.This thesis firstly introduces the development status of vacuum circuit breaker and discusses the importance of phase control technology in power system.10 kv principle and application of the overall structure of the permanent magnet vacuum circuit breaker,made a special analysis,focusing on the overall structure of the monostable permanent magnetic mechanism and working principle of a detailed introduction,on the basis of maxwell’s electromagnetic theory,the analysis of the magnetic field of permanent magnet mechanism,analysis of dynamic and static characteristics of the permanent magnetic actuator,establish the corresponding mathematical model of permanent magnetic actuator for parameter setting to provide important theoretical basis.At the same time,this paper analyzes the importance of the power transmission mechanism-boom connecting rod in the action process of circuit breaker,compares several different sizes of boom connecting rod,carries on the comparison of simulation and actual measurement,and summarizes the optimal size of boom connecting rod.Finally,the integration of the previous analysis data,the use of mechanical characteristics tester and other equipment on the circuit breaker performance test,analysis of the circuit breaker parameters data meet the requirements.In this thesis,the structural characteristics of permanent magnet mechanism and lever connecting rod are described in detail by means of analysis,calculation,simulation and actual measurement,which verifies the feasibility of the whole machine design method and provides a good idea for the subsequent development of phased circuit breaker.At present,the phase-controlled circuit breaker studied in this project has been put into operation for more than three years on a pilot basis,and is distributed in more than ten counties and cities in six provinces.The overall operation effect is very good,and no adverse events have occurred on the site.