電氣專業(yè)畢業(yè)設計外文翻譯---單一的神經網絡pi控制高可靠性直線電機磁浮-電氣類(文件)
【正文】 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)v], (2) where Q is a dimensionless parameter representing the motor length on the normalized time scale. The average value of secondary eddy current is ? ?? ??? Q Qmxmea QeIdxeQII 02 1 (3) Equivalent exciting current is ? ?? ?QeIIII Qmeamma /112 ?????? (4) where Imea is the equivalent exciting current considering the dynamic end effect. The demagizing effect can be reflected by amending the exciting current, so the total exciting current is： 14 ? ?? ?QeL Qm /11 ??? (5) The virtual value of the secondary eddy current at entry is QeIdxeQIIQmQ xmer 2120222 ?? ??? ? (6) The eddy current loss at entry end is QeRIRIPQrmrere nt r y 212222???? (7) The eddy current loss at exit end is ? ? ? ?QeRIT eILP QrmQmre x i t 2121 222 ?? ????? (8) The total loss of the secondary is ? ? QeRIPPP Qrme x i te nt r ye dd y /12 ????? (9) The eddy current loss can be described as a series resistance (Rr(1?e?Q)/Q) in exciting circuit. Suppose f(Q)=(1?e?Q)/Q, the Ttype equivalent circuit considered the end effect is shown in . MODEL OF LIM CONSIDERING END EFFECT In the secondaryflux oriented vector control, the synchronous reference frame is aligned to the secondaryflux. There is no ponent along the q axis, ψrd=ψ2, ψrq=0. Based on above analysis, the LIM model is described as follows: 15 ? ?? ? sqt sdrdsdrsdssd ddiiQfRiRu ????? 1????? (10) sdspspssp dtdiRu ????? 1??? (11) ? ?? ? dtdiiQfRiR rdrdsdrrdr ?????0 (12) ? ? rdrqr iR ????? 210 ??? (13) ? ?? ? ? ?? ? rdmsdmssd iQfLiQfLL ???? 1? (14) rqmsqSsq iLiL ??? (15) ? ?? ? ? ?? ? rdmrsdmrd iQfLLiQfL ???? 1? (16) r
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