综合考虑起动转矩与牵入转矩时转子电阻优化设计

Optimal Design of Rotor Resistance Based on an Overall Consideration of Starting Torque and Pull-in Torque

针对油田等电机常处于轻载运行的场合,为了实现较低功率等级自起动永磁电机替换原异步电机的目的,需要合理匹配自起动永磁电机的起动转矩和牵入转矩提高其带载起动能力,而转子电阻的改变会影响电机起动转矩与牵入转矩的比例,进而影响电机的带载起动能力。本文从理论上对电机的起动转矩和牵入转矩进行了分析,分析转子电阻对两者的影响,以笼型转子的电导率为变量,起动时间为衡量标准,利用有限元仿真求得恒转矩负载时转子电阻与电机带载起动能力的关系,总结出转子电阻对电机带载起动能力的影响规律,为电机转子电阻的设计提供了依据。

For the occasions of where motors often in light load such as oil fields, in order to realize the pur- pose of replacing original induction motor with the low power rating line-start PMSM, the starting torque and pull-in torque of line-start PMSM should be reasonably matched to promote motor＇s capacity of starting with load, the change of rotor resistance will affect the ratio of motor＇s starting torque and pull-in torque, thereby affecting motor＇s capacity of starting with load. In this paper, the starting torque and pull-in torque of the motor were analyzed in theory, and the influence of rotor resistance on starting torque and pull-in torque was also analyzed, taking the electrical conductivity of the cage rotor as variable, the starting time and maximum ability of starting with load for measurestandard, obtaining the relationship between rotor resistance and motor＇s ability of starting of constant torque load using finite element simulation. The influence of rotor re- sistance on motor＇s ability of starting with load was summarized, which provided a basis for the design of motor＇s rotor resistance.