Analyses And Calculation Of Dynamic Behavior Of Hydraulic Operating Mechanism For LW-252 SF6 Circuit Breaker

In china, the development and manufacture of the hydraulic operating mechanism applied in high voltage circuit breaker have been performed before 1980s. Recently, with the advance of manufacture technology and the technics of the hydraulic operating mechanism in china has reached a novel high level. At the same time, it inherits the advantages, such as less parts, higher reliability, stable output performance and larger power. In this thesis, based on the succeeding development of hydraulic operating mechanism of LW-252, the theoretical study of the hydraulic operating mechanism is researched for effectively designing and optimizing the operating mechanism.In this thesis, the operating principle and main characteristics of the operating mechanism have been analyzed. Moreover, based on the actual hydraulic operating mechanism of the LW-252 SF6, the structure of the first to the third level valve for the three-phase operating hydraulic mechanism have been researched. Especially, the moving time, the delay time and the corresponding problems for the third level valve has been deeply investigated, comprehensively from the combination of the theoretical and testing aspects. And from the moving time and the velocity performance of the valve system, the engineering design of the hydraulic mechanism has been discussed.In the calculation of the moving time of the third level valve of the actual hydraulic operating mechanism for the LW-252 SF6 circuit breaker, the combination method of the hydrodynamics and kinetics has been applied for investigating the problem of the time delay under no-load and load interrupting cases. From the comparison of the theoretical and testing results, the tested delay time is longer than the theoretical due to the existing gas in the command tube. And the exhausting device has been designed for satisfying the consistency and stability of closing course of the circuit breaker.In this thesis, the velocity characteristic of the hydraulic operating mechanism velocity has been modeling and analyzed. And the numerical solving method has been proposed, the correcting parameters of the solving equation has been given. Moreover, the effect of the technical specification on the velocity characteristic has been discussed.