Study On Differential Evolution Algorithm Application In Universal Circuit Breaker

The utility model relates to a universal circuit breaker used in the power distribution system.The model is used for protecting the power distribution lines and the electric equipment,so as to avoid the damage of short circuit,overload,under voltage and ground fault current.The reliable switching of the contact is the foundation of the reliable operation of the universal circuit breaker.The contact spring can prevent the contact from bouncing.Energy storage spring provides energy to ensure contact closure.Although the spring designed by the common method can meet the working requirements of the circuit breaker,the unreasonable structure parameters will reduce the service life of the circuit breaker.Therefore,it is very important to design a simple and reasonable contact spring and energy storage spring.As a global optimization algorithm,differential evolution algorithm has good robustness and applicability.However,it is easy to fall into the local optimum,and the premature phenomenon occurs.Its weight factor and the crossover probability are usually set to the fixed value of experience,resulting in the slow convergence speed of the algorithm.The cloud model can reflect the relationship between randomness and fuzziness,and improve the differential evolution algorithm to speed up the convergence rate.For this purpose,on the basis of the improved differential evolution algorithm,the application of this algorithm in the optimization of contact spring and energy storage spring in the universal circuit breaker is studied.(1)Improved differential evolution(ECDE)algorithm based on cloud model is studied.In order to solve the problem of differential evolution(DE)algorithm,it is easy to fall into local optimum,premature and slow convergence speed.The improved differential evolution(ECDE)algorithm based on cloud model is studied.The weight factor and crossover probability are dynamically adjusted by the cloud model.The number of candidate solutions is increased,the convergence rate is accelerated and the local optimum is avoided.Classical function tests show that the ECDE algorithm is better than ECDE algorithm and DE algorithm.(2)The application of the cloud ECDE algorithm in the optimization of contact spring is studied.In order to optimize the structural parameters of the contact spring of universal circuit breaker and to reduce contact wear,firstly,the mathematical model of contact spring is analyzed.Then,the fitness function is designed.Finally,the structural parameters of contact spring are optimized by using a cloud ECDE algorithm.The experiments of HSW6-A,HSW6-B and HSW6-C circuit breakers show that the cloud ECDE algorithm is superior to the trial calculation method in the design effect,and the contact wear is reduced and the ignition of the contract is avoided.(3)The application of the cloud ECDE algorithm in the optimization of energy storage spring is studied.In order to optimize the structural parameters of the energy storage spring of the universal circuit breaker and to reduce energy consumption,firstly,the mathematical model of the energy storage spring is analyzed.Then,the fitness function is designed.Finally,the structural parameters of energy storage spring are optimized by cloud ECDE algorithm.Through the experiments of three typical circuit breakers,the results show that the optimal design of cloud ECDE algorithms is superior to the experimental results,and energy waste is avoided and mechanical wear is reduced.