电气专业毕业设计外文翻译---单一的神经网络pi控制高可靠性直线电机磁浮-电气类(编辑修改稿)

电气专业毕业设计外文翻译---单一的神经网络pi控制高可靠性直线电机磁浮-电气类(编辑修改稿)内容摘要：

ified by simulations. Key words: Linear induction motor (LIM), Fieldoriented control, End effect INTRODUCTION The linear inductance motor (LIM) is used in such lowspeed Maglev system as HSST system to drive vehicles (Wu, 2020). LIM has the end effect owing to its unique configuration. The eddy current produced by the dynamic end effect causes additional loss of linear motor which reduces thrust (Duncan and Eng, 1983。 Boldea and Nasar, 1999). When the vector control strategy is applied to LIM, the influence of the end effect must be considered and an exact mathematical model should be constituted to improve the whole performance of the control system. In this paper, the equation circuit of LIM considering large end effect is discussed, and the calculation model of LIM is deduced. The intelligent control method is adopted to solve the problem of robustness. The single neuron control PI unit is adopted for LIM servodrive because of its simple configuration. The simulation has validated the obvious effects of those 12 methods on improving the whole performance, including reliability. EQUATION CIRCUIT OF LIM CONSIDERING END EFFECT In a long secondary type LIM, as the primary moves, the secondary is continuously replaced by new material. This new part material tends to resist a sudden increase in flux peration and only allows a gradual buildup of the flux density in air gap. Eddy current in the entry or exit end of secondary plate will be produced because of a sudden change of magic flux. This inductive current will prevent the change of air gap magic field (Sung and Nam, 1999). Considering the dynamic end effect, the effective length of linear motor’ primary is supposed as l, and the secondary parameter is converted into the primary’s. At the entry end of secondary core, the eddy current increases promptly, and the increasing rate can be decided by T1=Lr1/Rr (Lr1 is the secondary leaking inductance converted into the primary’s, Rr is the secondary equivalent resistance converted into theprimary’s). Because T1=Lr1/Rr is very small and can be neglected, the secondary eddy current can reach the primary exciting current Im rapidly, while the phase of eddy current is contrary with primary current. The time constant of secondary eddy current decrease can be described as T2=(Lm+Lr1)/Rr=Lr/Rr (Lm is the mutual inductance of LIM). At the exit of secondary plate, the eddy current increases to Im promptly, and then decreases with the time constant T1. The transient process is shown in . Based on the above analysis, the end effect can be added into the equivalent circuit. 13 The relative velocity between the primary and secondary decides the distribution of magic flux along air gap. Suppose v is the primary velocity, in T2 time the primary moves a length of vT2. The time of the primary passing a point on the secondary is Tv=l/v. (1) Then normalize the motor length Q=l/(vT2)=vTv/(vT2)=Tv/T2=lRr/[(Lm+Lr1。