電氣專業(yè)畢業(yè)設(shè)計(jì)外文翻譯---單一的神經(jīng)網(wǎng)絡(luò)pi控制高可靠性直線電機(jī)磁浮

1、<p>　　單一的神經(jīng)網(wǎng)絡(luò)PI控制高可靠性直線電機(jī)磁浮</p><p>　　摘要：本文論述了一種可以改善系統(tǒng)可靠性的新型線性鼠籠電機(jī)（linear induction motor, LIM）從LIM的標(biāo)準(zhǔn)電路方程考慮動(dòng)力學(xué)終端效應(yīng)，當(dāng)制動(dòng)特性同時(shí)作為影響力時(shí)，可以建立包含有大的補(bǔ)償終端效應(yīng)的等效電路模型。等效電路模型可以用作LIM的二次磁場(chǎng)定向控制。同時(shí)討論了單神經(jīng)網(wǎng)路PI單元作為L(zhǎng)IM的輔助驅(qū)動(dòng)效果，

2、驅(qū)動(dòng)控制的數(shù)學(xué)模型的有效性通過(guò)模擬實(shí)驗(yàn)被證實(shí)。</p><p>　　關(guān)鍵字：線性鼠籠電機(jī)（LIM）,磁場(chǎng)定向控制，終端效應(yīng)</p><p><b>　　前 言</b></p><p>　　線性鼠籠電機(jī)是在低速磁浮系統(tǒng)中作為耐熱系統(tǒng)，來(lái)驅(qū)動(dòng)車輛。LIM之所以有終端效應(yīng)取決于它獨(dú)特的裝置。由動(dòng)力學(xué)終端效應(yīng)產(chǎn)生的渦流動(dòng)力導(dǎo)致了線性電機(jī)的額外損失，從

3、而減少了推動(dòng)力。當(dāng)矢量控制策略應(yīng)用于LIM時(shí)，就必須考慮終端效應(yīng)的影響，并且建立更精確的數(shù)學(xué)模型來(lái)完善控制系統(tǒng)的整體性能。</p><p>　　在本文中，討論了在考慮終端效應(yīng)很大時(shí)LIM的電路方程，推導(dǎo)出了LIM的計(jì)算模型。智能控制方法被用來(lái)解決人力所難以操作的問題。而單神經(jīng)PI控制單元之所以能被用于LIM的輔助驅(qū)動(dòng)是由于它簡(jiǎn)單的構(gòu)造。模擬實(shí)驗(yàn)已經(jīng)證實(shí)了這些模型在改善整體性能上的有效性和可靠性。</p>

4、;<p>　　考慮了終端效應(yīng)的LIM的電路方程</p><p>　　在一個(gè)長(zhǎng)的二級(jí)類型的LIM中，和一級(jí)不同的是在二級(jí)類型中連續(xù)更換了新材料，這種新材料傾向于抵制滲透通量的突然增加，且只允許空間間隙中滲透密度的逐漸積聚。在二級(jí)板塊的進(jìn)口端和出口端，因?yàn)榇磐康耐蝗晦D(zhuǎn)變，會(huì)產(chǎn)生渦流，這種感應(yīng)電流可以避免氣隙磁場(chǎng)的突然改變。</p><p>　　考慮到動(dòng)力學(xué)終端效應(yīng)，線性電機(jī)的有

5、效長(zhǎng)度假設(shè)為l，二級(jí)參數(shù)轉(zhuǎn)化為一級(jí)參數(shù)，在二級(jí)核心的進(jìn)口端，渦流迅速增加，增加速率可以由下式計(jì)算：</p><p>　　T1 = Lr1 / Rr</p><p>　　式中： Lr1——由二級(jí)轉(zhuǎn)化為一級(jí)的滲漏電感系數(shù)；</p><p>　　Rr ——由二級(jí)轉(zhuǎn)化為一級(jí)的等效電阻。</p><p>　　因?yàn)門1 = Lr1 / Rr的值很

6、小，故可以忽略。二級(jí)渦流可以迅速的達(dá)到一級(jí)勵(lì)磁電流，而一級(jí)電流的渦流階段則相反。二級(jí)渦流的時(shí)間常數(shù)的減少可以用下式描述：</p><p>　　T2 =（Lm+ Lr1）/ Rr</p><p><b>　　= Lr / Rr</b></p><p>　　式中： Lr——LIM的電感系數(shù)。</p><p>　　在

7、二級(jí)出口板上，渦流迅速增加至Im，然后隨著時(shí)間常數(shù)T1的變化而降低。瞬態(tài)過(guò)程見圖1.給予以上分析，終端效應(yīng)可以添加到等效電路中。</p><p>　　圖1：(a)氣隙磁動(dòng)力；(b)二級(jí)板磁動(dòng)力</p><p>　　一級(jí)和二級(jí)之間的相對(duì)速度決定了氣隙磁場(chǎng)的分布。假設(shè)ν是一級(jí)速度，在T2時(shí)間，一級(jí)的移動(dòng)長(zhǎng)度為νT2。一級(jí)通過(guò)二級(jí)的點(diǎn)的時(shí)間為：</p><p>　　(1)

8、則標(biāo)準(zhǔn)電機(jī)長(zhǎng)度為：</p><p>　　(2)在這里Q是一個(gè)無(wú)量剛的常數(shù)，代表了在標(biāo)準(zhǔn)時(shí)間尺度下的電機(jī)長(zhǎng)度，二級(jí)渦流的平均值為：</p><p>　　(3)等效勵(lì)磁電流為：</p><p>　　(4)這里Imea是考慮了動(dòng)力學(xué)終端效應(yīng)的等效勵(lì)磁電流。消磁效應(yīng)可以反應(yīng)修正的勵(lì)磁電流，所以總的勵(lì)磁電流為：</p><p>　　(5)在進(jìn)口端二級(jí)渦

9、流的虛擬值為：</p><p>　　(6)進(jìn)口端的渦流損失：</p><p>　　(7)出口端的渦流損失：</p><p>　　(8)二級(jí)過(guò)程中總的渦流損失：</p><p>　　(9)渦流損失可以定義為勵(lì)磁回路中的串聯(lián)電阻。設(shè)。圖2所示為考慮了終端效應(yīng)的T型等效電路。</p><p>　　圖2：LIM的等效電路圖&l

10、t;/p><p>　　考慮了終端效應(yīng)的LIM模型</p><p>　　在二級(jí)渦流的定向矢量控制中，同步參照系和二級(jí)渦流是一致的，在q軸線上無(wú)分量。Ψrd=Ψ2，Ψrq=0?；谝陨戏治觯琇IM模型的描述如下：</p><p>　　(10) </p><p>　　(11)

11、 </p><p>　　(12) </p><p>　　(13) </p><p>　　(14) </p><p>　　(15)

12、 </p><p>　　(16) </p><p>　　(17) </p><p>　　(18)

13、 </p><p>　　(19) </p><p>　　在式(19)中的第二部分，是終端效應(yīng)產(chǎn)生的動(dòng)力學(xué)動(dòng)力。</p><p><b>　　單神經(jīng)網(wǎng)絡(luò)PI單元</b></p><p>　　減少LIM模型中輔助驅(qū)動(dòng)系統(tǒng)的參數(shù)偏差很重要。智能控制方法被用來(lái)解決人力所難以操作的問題。而

14、單神經(jīng)PI控制單元之所以能被用于LIM的輔助驅(qū)動(dòng)是由于它簡(jiǎn)單的構(gòu)造。由于LIM中的氣隙很寬，而導(dǎo)致的滲漏磁力流很大，所以很難有一個(gè)精確的LIM模型。在LIM的輔助控制中引入人工神經(jīng)網(wǎng)絡(luò)是很有用的。其中單神經(jīng)控制更為實(shí)用。單神經(jīng)網(wǎng)絡(luò)的結(jié)構(gòu)圖見圖3。單神經(jīng)網(wǎng)絡(luò)的輸出為：</p><p><b>　　，</b></p><p>　　， （20） &

15、lt;/p><p>　　其中xi(k)(i=1、2、3)，代表了常規(guī)PID調(diào)節(jié)器的整體單元、比例單元和微分單元。</p><p>　　圖3 單神經(jīng)控制的PI單元</p><p><b>　　控制器的輸出為：</b></p><p><b>　　(21)</b></p><p>　

16、　其中,最大限額，相當(dāng)于線性電機(jī)的最大拉力，權(quán)重因子為：</p><p>　　， (22)</p><p><b>　　其中。</b></p><p>　　圖4所示的是二級(jí)渦流定向控制模型的電路圖，有一個(gè)LIM、一個(gè)帶有單神經(jīng)控制PI單元的速度反饋控制回路、一個(gè)PWM變壓器和一個(gè)矢量控制器組成。

17、</p><p>　　圖4：帶有單神經(jīng)控制PI單元的二級(jí)定向控制模型</p><p>　　圖4：帶有單神經(jīng)控制PI單元的二級(jí)定向控制模型</p><p>　　注：ASR—速度調(diào)節(jié)器；ATR—回路調(diào)節(jié)器；</p><p>　　AΨR—流量調(diào)節(jié)閥；SFB—速度反饋單元。</p><p><b>　　結(jié)果和討論&l

18、t;/b></p><p>　　基于以上對(duì)數(shù)學(xué)模型和控制計(jì)算的分析，有人做了一個(gè)LIM的模擬實(shí)驗(yàn)，對(duì)單神經(jīng)PI調(diào)節(jié)和普通PI調(diào)節(jié)做了對(duì)比。在輔助系統(tǒng)中所使用的LIM型號(hào)是三相的，Y端連接兩極、2.5kW、50Hz、380V。LIM的參數(shù)是：Rs=4.097Ω，Rr=8.8Ω，Ls=0.1002H，Lm=0.0771H,Lr=0.08H,τ=0.063m。</p><p>　　圖5中所

19、示是前面討論的LIM模型的模擬實(shí)驗(yàn)的結(jié)果。</p><p>　　圖5：模擬實(shí)驗(yàn)結(jié)果。(a)速度；(b)電流id；(c)電流iq</p><p>　　圖6所示為普通PI單元和單神經(jīng)網(wǎng)絡(luò)PI單元的速度追蹤實(shí)驗(yàn)結(jié)果的比較。在模擬實(shí)驗(yàn)中可以看出，單神經(jīng)網(wǎng)絡(luò)PI調(diào)節(jié)的反應(yīng)速度很快，并且穩(wěn)態(tài)誤差較小。，在階躍反應(yīng)中，速度波動(dòng)較小。</p><p>　　本文討論了判斷LIM終端效

20、應(yīng)的一種電路方程，此方程適用于終端效應(yīng)比較大時(shí)的條件。矢量控制的模型已經(jīng)提出，單神經(jīng)網(wǎng)絡(luò)PI單元已經(jīng)被用于LIM的輔助驅(qū)動(dòng)。模擬實(shí)驗(yàn)的結(jié)論表明，終端效應(yīng)可以通過(guò)此過(guò)程得到彌補(bǔ)，并且控制系統(tǒng)的性能有所改善。單神經(jīng)網(wǎng)絡(luò)PI單元適用于控制計(jì)算的設(shè)計(jì)。</p><p>　　圖6：階段反應(yīng)的速度曲線</p><p><b>　　參考文獻(xiàn)</b></p><p

21、>　　Boldea, I., Nasar, S.A., 1999. Linear electric actuators and generators. IEEE Trans. on Energy Conversion, 14(3):712-717. [doi:10.1109/60.790940]</p><p>　　Duncan, J., Eng, C., 1983. Linear induction

22、motor-equivalent-circuit model. Proc. IEE, 130(1):51-57.</p><p>　　Sung, J., Nam, K., 1999. A New Approach to Vector Control for a Linear Induction Motor Considering End Effects. Conference Record of the IEEE

23、 IAS Annual Meeting’1999, 4:2284-2289.</p><p>　　Takahashi, I., Ide, Y., 1993. Decoupling control of thrust and attractive force of a LIM using a space vector control inventor. IEEE Trans. Ind. Appl., 29(1):1

24、61-167.[doi:10.1109/28.195902]</p><p>　　Wu, X.M., 2003. Maglev Vehicle. Shanghai Science and Technology Press, Shanghai (in Chinese).</p><p>　　Ye, Y.Y., 2000. Linear Motor and Its Control. Machi

25、ne Press,Beijing (in Chinese).</p><p>　　Single neuron network PI control of high reliability linear induction motor for Maglev</p><p>　　FANG You-tong, FAN Cheng-zhi</p><p>　　Abstrac

26、t: The paper deals with a new model of linear induction motor (LIM) to improve the reliability of the system. Based on the normal equation circuit of LIM considering the dynamic end effect, an equivalent circuit model wi

27、th compensation of large end effect is constructed when the end effect force at synchronism is of braking character. The equivalent circuit model is used for secondary-flux oriented control of LIM. Single neuron network

28、PI unit for LIM servo-drive is also discussed. The ef</p><p>　　Key words: Linear induction motor (LIM), Field-oriented control, End effect</p><p>　　INTRODUCTION</p><p>　　The linear

29、inductance motor (LIM) is used in such low-speed Maglev system as HSST system to drive vehicles (Wu, 2003). LIM has the end effect owing to its unique configuration. The eddy current produced by the dynamic end effect ca

30、uses 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 exac

31、t mathematical model should be constituted to imp</p><p>　　In this paper, the equation circuit of LIM considering large end effect is discussed, and the calculation model of LIM is deduced. The intelligent c

32、ontrol method is adopted to solve the problem of robustness. The single neuron control PI unit is adopted for LIM servo-drive because of its simple configuration. The simulation has validated the obvious effects of those

33、 methods on improving the whole performance, including reliability.</p><p>　　EQUATION CIRCUIT OF LIM CONSIDERING END EFFECT</p><p>　　In a long secondary type LIM, as the primary moves, the secon

34、dary is continuously replaced by new material. This new part material tends to resist a sudden increase in flux penetration and only allows a gradual buildup of the flux density in air gap. Eddy current in the entry or e

35、xit end of secondary plate will be produced because of a sudden change of magnetic flux. This inductive current will prevent the change of air gap magnetic field (Sung and Nam, 1999).</p><p>　　Considering th

36、e 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,

37、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).</p><p>　　Bec

38、ause 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 seco

39、ndary 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 const

40、ant T1. The transient</p><p>　　process is shown in Fig.1. Based on the above analysis, the end effect can be added into the equivalent circuit.</p><p>　　The relative velocity between the primary

41、 and secondary decides the distribution of magnetic 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</p&g

42、t;<p>　　Tv=l/v. (1)</p><p>　　Then normalize the motor length</p><p>　　Q=l/(vT2)=vTv/(vT2)=Tv/T2=lRr/[(Lm+Lr1)v], (2)</p><p>

43、　　where Q is a dimensionless parameter representing the motor length on the normalized time scale. The average value of secondary eddy current is</p><p><b>　　(3)</b></p><p>　　Equival

44、ent exciting current is</p><p><b>　　(4)</b></p><p>　　where Imea is the equivalent exciting current considering the dynamic end effect. The demagnetizing effect can be reflected by am

45、ending the exciting current, so the total exciting current is：</p><p><b>　　(5)</b></p><p>　　The virtual value of the secondary eddy current at entry is</p><p><b>　

46、　(6)</b></p><p>　　The eddy current loss at entry end is</p><p><b>　　(7)</b></p><p>　　The eddy current loss at exit end is</p><p><b>　　(8)</b&

47、gt;</p><p>　　The total loss of the secondary is</p><p><b>　　(9)</b></p><p>　　The eddy current loss can be described as a series resistance (Rr(1?e?Q)/Q) in exciting circ

48、uit.</p><p>　　Suppose f(Q)=(1?e?Q)/Q, the T-type equivalent circuit considered the end effect is shown in Fig.2.</p><p>　　MODEL OF LIM CONSIDERING END EFFECT</p><p>　　In the seconda

49、ry-flux oriented vector control, the synchronous reference frame is aligned to the secondary-flux. There is no component along the q axis, ψrd=ψ2, ψrq=0. Based on above analysis, the LIM model is described as follows:<

50、;/p><p><b>　　(10)</b></p><p><b>　　(11)</b></p><p><b>　　(12)</b></p><p><b>　　(13)</b></p><p><b>　　(14)<

51、;/b></p><p><b>　　(15)</b></p><p><b>　　(16)</b></p><p><b>　　(17)</b></p><p><b>　　(18)</b></p><p><b>

52、;　　(19)</b></p><p>　　The second term in Eq.(19) acts as dynamic brake force caused by end effect.</p><p>　　SINGLE NEURON NETWORK PI UNIT</p><p>　　It is very important to reduc

53、e the parameter deviation of LIM model for servo-drive system. The intelligent control method has been adopted to solve the problem of robustness. The single neuron control PI unit is adopted for speed control because of

54、 its simple configuration (Ye, 2000).</p><p>　　Since the leaking magnetic flux in LIM is quite large for its wide air gap, it is difficult to have an accurate model of LIM. It is useful to introduce the arti

55、ficial neural networks into the LIM servo-control, where the single neuron control is more practical. The configuration of single neuron is shown in Fig.3. The input of single neuron is</p><p><b>　　，&l

56、t;/b></p><p>　　， (20) </p><p>　　where xi(k) (i=1, 2, 3) stand for integral unit, proportional unit and differential unit of normal PID adjustor.</p>

57、<p>　　The output of controller is</p><p><b>　　(21)</b></p><p>　　where |u(k)|≤Umax, Umax is the maximum of limitation, equal to the maximum given pull of linear motor. The weigh

58、t factor is</p><p>　　， (22)</p><p><b>　　where。</b></p><p>　　Fig.4 shows the block diagram of secondary-flux oriented control model, which consist

59、s of a LIM (Takahashi and Ide, 1993), a speed feedback control loop with single neuron control PI unit, a PWM voltage source translator, and vector control translation components.</p><p>　　ASR: Speed regulat

60、or; ATR: Torque regulator; </p><p>　　AψR(shí): Flux regulator; SFB: Speed feedback unit</p><p>　　RESULTS AND CONCLUSIONS</p><p>　　Based on the above analysis of mathematics model and con

61、trol arithmetic, a simulation for LIM is performed. Comparison between single neuron PI adjustment and normal PI adjustment has been performed. The LIM used in the serve system is three-phase Y-connected two-pole 2.5 kW

62、50 Hz 380 V type. The parameters of LIM are: Rs=4.097 Ω, Rr=8.8 Ω, Ls=0.1002 H, Lm=0.0771 H, Lr=0.08 H, τ=0.063 m.</p><p>　　Fig.5 presents simulation result by LIM model discussed above.</p><p&g

63、t;　　Fig.6 shows the comparison of speed tracking with normal PI unit and single neuron network PI unit. From the simulation, it can be concluded that the speed response of the single neuron network PI adjustment is fast,

64、 and the steady-state error is smaller.For step response, the speed fluctuation is small.</p><p>　　In this paper, an equation circuit considering the dynamic end effect of LIM is discussed, which is suitable

65、 for the large end effect condition. The model for vector control has been presented. Single neuron network PI unit is introduced for LIM servo-drive. The simulative conclusion shows that the end effect can be compensate

66、d by this model, and the control system performance is improved. The single neuron network PI unit is suitable for the control arithmetic design.</p><p>　　V: Set up speed; V1: Trace speed with PI unit;</p

67、><p>　　V2: Trace speed with single neuron network PI unit</p><p><b>　　參考文獻(xiàn)</b></p><p>　　Boldea, I., Nasar, S.A., 1999. Linear electric actuators and generators. IEEE Tran

68、s. on Energy Conversion, 14(3):712-717. [doi:10.1109/60.790940]</p><p>　　Duncan, J., Eng, C., 1983. Linear induction motor-equivalent-circuit model. Proc. IEE, 130(1):51-57.</p><p>　　Sung, J., N

69、am, K., 1999. A New Approach to Vector Control for a Linear Induction Motor Considering End Effects. Conference Record of the IEEE IAS Annual Meeting’1999, 4:2284-2289.</p><p>　　Takahashi, I., Ide, Y., 1993.

70、 Decoupling control of thrust and attractive force of a LIM using a space vector control inventor. IEEE Trans. Ind. Appl., 29(1):161-167.[doi:10.1109/28.195902]</p><p>　　Wu, X.M., 2003. Maglev Vehicle. Shang