Research On Optimization Design And Unlocking Reliability Of Hydraulic Electromagnetic Circuit Breaker

As a component of control,drive and protection functions,hydraulic electromagnetic circuit breaker is widely used in ship,missile,carrier rocket,satellite and other fields.Its reliability has a significant impact on the combat capability and operational performance of weapon equipment.Due to the use of dimethyl silicone oil with stable viscosity,its tripping characteristics are almost not affected by the environment.However,due to the short development cycle and the weak consistency of theoretical design,the problem of unreliable unlocking has occurred many times in recent years,so it is necessary to study the unlocking problem.Based on the robust design theory,this paper optimizes the design of hydraulic electromagnetic circuit breaker,and establishes the unlocking reliability evaluation model based on stress-strength interference through torque matching relationship.The purpose is to improve the unlocking reliability(qualification rate)of batch circuit breaker products to 100%.Firstly,through the establishment of the finite element model of the electromagnetic system of the hydraulic electromagnetic circuit breaker and the multi-body calculation model of the locking torque of the operating mechanism based on the clearance between the hole and the shaft,the virtual prototype is completed.Based on the virtual prototype model,the basic characteristics of electromagnetic system and operating mechanism of the circuit breaker are analyzed,and the simulation data of the virtual prototype are compared with the experimental test data to verify the effectiveness of the virtual prototype simulation model,so as to lay a theoretical foundation for the next approximate modeling and robustness optimization.Secondly,for the sake of meeting the requirements of quality characteristic analysis and robust design of a large number of orthogonal experiment calculation,on the one hand,a fast calculation model based on Taylor expansion is established by fitting method;On the other hand,for the sake of avoiding the disadvantages of traditional BP neural network algorithm such as over fitting,slow iterative convergence,low prediction accuracy and falling into local optimal solution,a fast calculation model of BP neural network for circuit breaker based on LM(Levenberg-Marquardt)algorithm is proposed.By comparing the iterative convergence speed and prediction accuracy of traditional BP algorithm and LM-BP algorithm,the superiority of LM-BP algorithm is proved.Compared with the fast calculation model based on Taylor expansion,LM-BP can obtain higher calculation accuracy with fewer sample points.Then,for the sake of improving the unlocking reliability of the circuit breaker,the robustness parameters of the circuit breaker electromagnetic system are designed.The key design parameters are selected,and the optimal design parameter center value which can improve the system output characteristics and anti-jamming performance is obtained by arranging the internal and external orthogonal experiment(DOE)design,based on the fast calculation algorithm and using the significant signal-to-noise ratio and sensitivity variance analysis.The effectiveness of the parameter design is verified by the finite element verification of the output characteristics of the electromagnetic system and the robustness verification of the Monte Carlo virtual sample.And then by establishing the stress-strength interference model of locking torque and tripping torque of the circuit breaker before and after the parameter design,the unlocking reliability of the circuit breaker is evaluated.Finally,for the sake of making the unlocking reliability of the circuit breaker meet the target requirements,the robustness tolerance design of the electromagnetic system is carried out.Based on the fast calculation model,the external table orthogonal tests are arranged,through the contribution rate analysis and combined with the tolerance design formula,the tolerance of design parameters is improved,and so the unlocking reliability of circuit breaker is improved.By analyzing the shortcomings of traditional tolerance design,this paper also studies an improved tolerance design,that is,variable contribution rate tolerance design.On the one hand,the contribution rate of DOE design is calculated by function call,on the other hand,the Monte Carlo virtual sampling is realized by fast calculation algorithm,and then the distance between the current standard deviation and the qualified threshold is calculated,so as to realize the automatic optimization allocation of parameter tolerance and improve the optimization design accuracy.And then by establishing the stress-strength interference model of locking torque and tripping torque of the circuit breaker before and after the tolerance design,the unlocking reliability of the circuit breaker is evaluated.Through robust design,the optimization goal of improving the unlocking reliability(qualification rate)of batch circuit breaker products to 100% is achieved.Based on the rapid calculation modeling and robust optimization design,this paper solves the problem of reliability and consistency improvement of hydraulicelectromagnetic circuit breaker unlocking,which is of great significance to guarantee and improve the quality and reliability of the same type of circuit breaker products,so as to meet the national requirements for long life and high reliability of low-voltage electrical appliances.The design theory and optimization method can be applied to the reliability research of other electrical appliances,electronic products or electromechanical components.