The performance characteristics,particularly the starting performance of direct line-fed induction motors,which are mainly influenced by the design of the rotor,are crucial considerations for end-users.It is quite a c...The performance characteristics,particularly the starting performance of direct line-fed induction motors,which are mainly influenced by the design of the rotor,are crucial considerations for end-users.It is quite a challenging issue for motor manufacturers to enhance the starting performance of existing mass-produced motors with minimal modifications and expenses.In this paper,a simple and cost-effective method to improve the starting performance of a commercial squirrel-cage induction motor(SCIM)is proposed.The influence of geometric parameters of the end-ring on the performance characteristics,including starting(locked rotor)torque,pull-up and break down torque,starting current,rotor electric parameters,current density,power losses,and efficiency have been comprehensively investigated.It has been revealed that among the other end-ring design parameters,the ring thickness has a significant effect on the performance characteristics.An optimal end-ring thickness is determined,and its performance characteristics have been compared to those of its initial counterpart.Numeric and parametric analyses have been conducted using a 2D time-stepping finite element method(FEM).The FEM results were validated using experimental measurements obtained from an 11 kW SCIM prototype.展开更多
异步起动永磁同步电机由于其高效率、高功率因数及良好的起动性能,被广泛应用于大起动转矩场合.针对油田抽油机场合,设计一台30 k W切向转子结构异步起动永磁同步电机,以效率与起动转矩为优化目标,利用响应面法建立隔磁桥尺寸、转子槽...异步起动永磁同步电机由于其高效率、高功率因数及良好的起动性能,被广泛应用于大起动转矩场合.针对油田抽油机场合,设计一台30 k W切向转子结构异步起动永磁同步电机,以效率与起动转矩为优化目标,利用响应面法建立隔磁桥尺寸、转子槽尺寸及永磁体尺寸与效率和起动转矩之间的响应模型,利用布谷鸟算法寻求响应模型的最优转子尺寸,得到满足抽油机场合的高效率、高起动转矩的电机转子参数.建立优化前后的电机有限元分析模型,对比分析优化前后样机的起动性能,仿真结果证明优化方法的精确性与合理性.展开更多
Theory has it that increasing the step length improves the accuracy of a method. In order to affirm this we increased the step length of the concept in [1] by one to get k = 5. The technique of collocation and interpo...Theory has it that increasing the step length improves the accuracy of a method. In order to affirm this we increased the step length of the concept in [1] by one to get k = 5. The technique of collocation and interpolation of the power series approximate solution at some selected grid points is considered so as to generate continuous linear multistep methods with constant step sizes. Two, three and four interpolation points are considered to generate the continuous predictor-corrector methods which are implemented in block method respectively. The proposed methods when tested on some numerical examples performed more efficiently than those of [1]. Interestingly the concept of self starting [2] and that of constant order are reaffirmed in our new methods.展开更多
文摘The performance characteristics,particularly the starting performance of direct line-fed induction motors,which are mainly influenced by the design of the rotor,are crucial considerations for end-users.It is quite a challenging issue for motor manufacturers to enhance the starting performance of existing mass-produced motors with minimal modifications and expenses.In this paper,a simple and cost-effective method to improve the starting performance of a commercial squirrel-cage induction motor(SCIM)is proposed.The influence of geometric parameters of the end-ring on the performance characteristics,including starting(locked rotor)torque,pull-up and break down torque,starting current,rotor electric parameters,current density,power losses,and efficiency have been comprehensively investigated.It has been revealed that among the other end-ring design parameters,the ring thickness has a significant effect on the performance characteristics.An optimal end-ring thickness is determined,and its performance characteristics have been compared to those of its initial counterpart.Numeric and parametric analyses have been conducted using a 2D time-stepping finite element method(FEM).The FEM results were validated using experimental measurements obtained from an 11 kW SCIM prototype.
文摘异步起动永磁同步电机由于其高效率、高功率因数及良好的起动性能,被广泛应用于大起动转矩场合.针对油田抽油机场合,设计一台30 k W切向转子结构异步起动永磁同步电机,以效率与起动转矩为优化目标,利用响应面法建立隔磁桥尺寸、转子槽尺寸及永磁体尺寸与效率和起动转矩之间的响应模型,利用布谷鸟算法寻求响应模型的最优转子尺寸,得到满足抽油机场合的高效率、高起动转矩的电机转子参数.建立优化前后的电机有限元分析模型,对比分析优化前后样机的起动性能,仿真结果证明优化方法的精确性与合理性.
文摘Theory has it that increasing the step length improves the accuracy of a method. In order to affirm this we increased the step length of the concept in [1] by one to get k = 5. The technique of collocation and interpolation of the power series approximate solution at some selected grid points is considered so as to generate continuous linear multistep methods with constant step sizes. Two, three and four interpolation points are considered to generate the continuous predictor-corrector methods which are implemented in block method respectively. The proposed methods when tested on some numerical examples performed more efficiently than those of [1]. Interestingly the concept of self starting [2] and that of constant order are reaffirmed in our new methods.
