长初级双边直线感应电机制动特性研究

Research on Braking Characteristics of Long Primary Double-sided Linear Induction Motor

长初级双边直线感应电机(double-sided linear induction motor,DSLIM)制动时短次级作用区域与未作用区域的气隙磁场不同,造成的纵向动态边端效应对电机制动性能产生一定影响。该文建立长初级DSLIM解析模型,在考虑电机横向边端效应与纵向动态边端效应的基础上,推导长初级DSLIM回馈制动与直流能耗制动时气隙磁密和制动力解析公式,分析长初级DSLIM随滑差率、品质因数、次级速度、次级电阻等参数变化下的制动特性,定量分析纵向动态边端效应对回馈制动与直流能耗制动的不同影响。研究显示电机回馈制动时的纵向动态边端效应在滑差率接近零时变小,直流能耗制动时的纵向动态边端效应在最大制动力时最强,通过增加次级作用区域极数和电机低滑差率制动能有效抑制纵向动态边端效应。建立了一台实验样机三维有限元模型,进行了仿真与实验,结果验证了长初级DSLIM制动特性计算方法的准确性与实用性。

The braking performance of long. primary double-sided linear induction motor （DSLIM） is influenced by longitudinal dynamic end effect, which results from the difference of secondary covered and rest air-gap filed. Analysis model of long primary DSLIM was established, formulas for flux density of air-gap and braking force were deduced by considering transverse and longitudinal dynamic end effects. The relations that braking force with slip, G-factor, secondary speed and conductivity, etc were analyzed. Comparative analysis shows that the longitudinal dynamic end effect is waken when slip approximates zero under regenerative braking and is aggravated when force reaches maximum under DC dynamic braking. Increasing secondary covered poles and braking in low slip of motor can restrain longitudinal dynamic end effect. Lastly, 3D finite element model （FEM） of prototype was built to obtain the flux density distribution and DC dynamic braking force. Simulation and experiment results verify the feasibility and effectiveness of the calculation method.