| With the good start of China’s 14 th Five-Year Plan proposed by General Secretary Xi Jinping,my country’s economy and national strategic scientific and technological strength are rapidly growing,and the power industry is also developing steadily.my country’s power system is gradually moving towards large capacity,ultra-high voltage,and intelligence.When a large-capacity power grid fails,the short-circuit current generated is very large.Once the disconnection is not timely,it will cause serious power accidents and cause great harm to the safe and stable operation of the power grid.High-speed circuit breakers have become a research hotspot in the field of high-voltage electrical appliances in recent years because they can significantly shorten the breaking time and reduce the impact of short-circuit current on the power system.Compared to traditional high voltage circuit breakers,the high voltage circuit breaker opening process is more time consuming,more impactful and more vibrating,making it ideal for testing the mechanical structure of operating mechanisms and the strength of components.High-speed circuit breaker requirements for short-term fire extinguishing also test the fire extinguishing level of the fire extinguishing chamber.Therefore,in this paper,we focused on the study of the mechanical properties of the operating mechanism of the high-speed circuit breaker and the fire extinguishing ability of the fire extinguishing chamber.This paper focuses on high-speed circuit breakers and the hydraulic operation mechanisms that support them during the development stage of large-scale state-owned enterprises,and establishes a three-dimensional mathematical model using mechanical mechanics and fluid mechanics as basic principles.Hydraulic operation mechanism,high speed circuit breaker 2D arc fire extinguishing room math model,simulation calculation and analysis by professional simulation software,dynamic characteristics of hydraulic operation mechanism are obtained,and arc fire extinguishing performance breaker of high speed circuit is verified.The main research contents of this paper are as follows.Based on the knowledge of hydraulic transmission and the latest control theory,a mathematical model of the opening period of the hydraulic operating mechanism and a mathematical model of hydraulics are established through the description of the operating process of the hydraulic system in the opening operation.Operation mechanism simulation and analysis Based on the knowledge of hydraulic operation mechanism control performance rigid body mechanics,we simulated and analyzed a three-dimensional mathematical model of the hydraulic operation mechanism auxiliary switch device,and each of the hydraulic operation mechanism auxiliary switches during the opening process.Simulates the dynamic characteristics of a component.And then the idea of structural mechanics calculation.Based on the theoretical knowledge of structural mechanics,through the analysis of the simulation results,the stress and strain of each component of the auxiliary switch of the hydraulic operating mechanism under dangerous conditions are obtained.The modal calculation is performed for the auxiliary switch connector to obtain its resonance frequency and amplitude,so as to avoid the abnormal working state of the auxiliary switch caused by resonance.Finally,the fatigue resistance and life of key parts are analyzed through fatigue simulation software,which provides a theoretical basis for the reliability of the mechanism and the optimization of products.We established a mathematical model of the high-speed circuit breaker airfield and used fluid dynamics software to simulate the airfield of the high-speed circuit breaker model under conditions that cut off a short-circuit current of 50 k A.The pressure monitoring curve is used to analyze the breaking characteristics of the high speed circuit breaker and verify its excellent arc fire extinguishing ability. |
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