外文翻譯--正弦PWM電壓源逆變器供電的永磁直線同步電機(jī)低速負(fù)載性能

1、中文3000字文獻(xiàn)翻譯原文LOAD PERFORMANCE OF PMLSM IN LOWER SPEEDREGION FED BY SINUOIDAL PWM INVERTERSi Jikai1,2 Chen Hao1 Wang Xudong2 Yuan Shiying2 Shangguan Xuanfeng21. China University of Mining and Technology Xuzhou 221008 China2. Henan Polytechnic University Jiaozuo 454000 ChinaABSTRACTFor the permanent m

2、agnet linear synchronous motor (PMLSM) fed by sinusoidal PWM voltage source inverter in the lower speed condition without feedback control, load performance isdifferent from the PMLSM working in high speed region. The paper adopts time-step finite elementmethod and field circuit coupling method to i

3、nvestigate load performance of the PMLSM to drive horizontal transportation system with light load and heavy load condition respectively. It is shown that load performance of the PMLSM in the heavy load condition is highly better than those in light load operation conditions, and operation current b

4、ecomes lower with load increasing. The validity is verified by comparisons of simulation and experimental results.Keywords: Permanent magnet linear synchronous motor (PMLSM), load performances, sinusoidal,PWM (SPWM) inverter, time-step finite element method, field circuit coupling method1 Introducti

5、onThe permanent magnet linear synchronous motor(PMLSM) has been widely used in many applications from transportation system to office automation and military devices because the motors have lots of merits as high efficient, high accuracy position control, etc1-4. However, it is necessary that load p

6、erformance of lower speed of PMLSM is profoundly researched, which has lots of characteristics to different from rotating synchronous machine and PMLSM in the high speed region. PMLSM in lower speed region has the essential characteristics that there are large ratio of the motor resistance to induct

7、ance and large leakage inductance because of large and effective air gap and lower operation frequency. Lots of PMLSMs have the characteristics because the moving track of PMLSM is limited and the mover steady state running speed of PMLSM is finite. In the Ref.5,specifications of PMLSM were as follo

8、w. The motor operation frequency was 6Hz, the pole pitch was 30mm. In the literature FEA method for electric machines driven by PWM inverter was proposed and the value of time-step was changed according to the, the inductance was 2.8mH,the motor was running at 0.9m/s. Ref.8 had presented the steady-

9、state performance of PMLSM based on sinusoidal ac current source such as larger ratio of resistance and inductance, and the mover in and out the primary. Unfortunately, as for the PMLSM fed by SPWM inverter operated in lower operation frequency region with larger ratio of resistance and inductance a

10、nd larger leakage inductance, the study of dynamic performance is poor in above-mentioned literatures and it is important to investigate the motor dynamic performance in difference loads conditions.Recently, many numerical methods have been proposed to investigate motors dynamic performance through

11、accurate magnetic field analysis. One of the numerical methods based on the finite element method, which is more and more used to accurately investigate dynamic characteristics of specify and new machines structures or asymmetry magnetic field, can consider geometric details and the nonlinear of mag

12、netic circuit9-11. As for PMLSM, it has threephase windings unbalance, magnetic circuit opening, bigger ratio of resistance and inductance of the phase windings, and time harmonic for the motor current existence. It is difficult to study the motor performances adopting the analytical method and the

13、conventional FEM with objective of one or two poles considering period boundary conditions, additionally considering the linkage questions of outer SPWM inverter and magnetic field, thus, the paper uses total model of the motor FEA to attain transient process performances such as thrust, the mover s

14、peed and windings current in different load conditions. Due to the PMLSM fed by SPWM voltage source inverter, the currents of the motor are unknown and voltage includes lots of harmonic components, the effect of using one tool of finite element method is not ideal. Thus time-step finite element meth

15、od and coupling field circuit method is adopted to investigate load performances of the motor driving horizontal transportation system. The paper presents simulation tools, which using time-step finite element method and field circuit coupling method and experiment to investigate the motor performan

16、ces in two loads conditions, light load and heavy load. The paper is organized as follows. In section , the prototype PMLSM is described. FEM model is established in section . Insection simulation results of PMLSM load performances are attained and discussed. In section experimental results are pres

17、ented. Lastly, in section some conclusions are drawn.2 Analysis modelThe primary is composed of three-phase windings and core opened slot, and the secondary consists in permanent magnets and the separated magnetism piece which placed on the surface of the iron yoke. Single side type short primary an

18、d surface mounted PMLSM are shown in Fig.1, in which permanent magnet magnetization is unanimous to air gap flux axis, leakage flux in poles interval lower and craftwork simple. The specifications of PMLSM are shown in Table.Table PMLSM specificationsFig.1 Physical model of surface permanent magnet

19、linear synchronous motorThe primary 2Tooth 3Slot 4Material of insulating magnet 5Permanent magnet 6The secondary yokeTo take circuit fed by SPWM voltage source inverter and the motor end effects into account, the paper adopts field-circuit coupling method to calculate electromagnetic transient proce

20、ss, solve equation variables of magnetic vector potential and the motor phase current, which are combination of electromagnetic field time-step finite element Equ. and threephase windings circuit equations. by electromotive force in the armature windings. Transient field governing equations. in whic

21、h Az denotes magnetic vector potential is variable are shown in Eq.(1) according to Maxwell equationswhere Azz-axis component of magnetic vector potentialJsCurrent density of the primary windingsJmEquivalent magnetizing surface current density of permanent magnetThe permeabilityIn the paper, the 2-D

22、 model is subdivided into small triangle elements to form a mesh that covers the entire region adopting n-order unit basic function and linear interpolation. After applying the Galerkin method, thegoverning equations. for the analysis model is expressed aswhere AUnknown magnetic vector potential (A

23、is used in Eq.(1) with different meaning)ICurrent in the windingsS,C,T Coefficient respectivelyG Corresponding matrix of equivalent magnetization current densityEquivalent magnetizing surface current method is adopted to deal with NdFeB type permanent magnet, which is uniformity magnetization, regul

24、ation shape, and linear demagnetization. Intensity of magnetization sign is M0.PMLSM resistance and leakage reactance is not neglected due to the motor with large air gap characteristic. According to Ohm law and Faraday electromagnetic induction law, relation of electromotive force and voltage produ

25、ced the primary three-phase windings is shown in Eq.(4).where The windings flux linkageLlThe motor leakage inductanceRWindings resistanceUWindings phase voltagewhere NWinding effective turnsBFlux densityS1Winding effective area in the slotS2Coupled effective area of the primary and the secondaryTo P

26、MLSM magnetic circuit and electric circuit are unbalance, thus electric potential of the connector of star point is not equal to zero and the motor phase equations. should be changed as follows.Where U0Output voltage of the inverterg0The inverter switch on-off functionUdDirect voltage of bus linkMax

27、wells stress tensor is adopted to calculate PMLSM electromagnetic force, which includes all kinds of harmonics component electromagnetic force. The motor electromagnetic force tangential component is shown in Eq.(9).The motor electromagnetic force normal component is shown in Eq.(10).where L1Winding

28、 effective lengthL2Integral spaceBxx-axis flux density component in the air gap fieldByy-axis flux density component in the air gap fieldFT Electromagnetic thrust forceFN Normal electromagnetic forceMovement equation of PMLSM is shown in Eq.(11).where mMassvThe motor mover velocityFLLoad force4 Simu

29、lation resultsThe simulation conditions are as follows. Line voltage is 30V, module frequency is 2Hz, light load is 50N and high load is 130N, the motor rated synchronous speed is 0.156m/s, which are identical to experimental PMLSM parameters. The simulation results are attained from cosimulation of

30、 finite element function of magnetic field and space state function of outer circuit. The motor voltage results are neglected because the voltage inverter is not almost affected by the outer conditions. Fig.2 shows simulation results of three phase current in load 50N condition. Fig.3 displays simul

31、ation result of thrust force. In Fig.4, the mover speeds in load 50N condition are shown. Short dash line denotes the mover speed in load 50N condition under elimination of PMLSM detent force by changing end shape. Fig.5Fig.7 show respectively simulation results of three-phase current, thrust force,

32、 speed of the PMLSMin load 130N condition. From Fig.2 and Fig.5, it is shown that the three-phase currents of the PMLSM in load 50Ncondition are larger than those of in load 130N condition, according to every load condition the motor phase current is unbalance that a phase current value is almost cl

33、ose to b phase current, but both is larger than c phase current value because the PMLSM magnetic circuit is open and armature windings are discontinuous. In terms of comparison with Fig.3 and Fig.6, we can know that the tendency of the thrust force of the PMLSM in load 130N condition is favorable. A

34、s shown in Fig.4 and Fig.7, in load 130N condition, the staring performance of the motor iswell and there is little undulation. If the detent force produced armature core length of PMLSM is reduced, the mover speed is basically close to the synchronous speed, but it is impossible that it is absolute

35、ly same as synchronous speed because there are lots of harmonic components in current fed from SPWM voltageFig.2 Three-phase current in load 50N conditionFig.3 Thrust force in load 50N conditionFig.4 Speed with and without reducing detent force in load 50N conditioninverter and air gap field is unsi

36、nuso- idal even if driven system is with feedback control.Fig.5 Three-phase current in load 130N conditionFig.6 Thrust force in load 130N conditionFig.7 Speed in load 130N condition5 Experimental resultsExperimental inverter type is FR-A241E-55K inverter of Mitsubishi corp. Voltage and current hall

37、sensors are used to detect signs. The mover speed is attained by the rotating encoder for E6B2 type, whose rotating speed can be converted into the motor line speed. Software of the data collection system is edited through Turbo C language.Fig.8 and Fig.11 show three-phase current in load 50N and 13

38、0N condition, respectively. Thrust force of the motor in two loads condition is shown in Fig.9 and Fig.12. From Fig.10 and Fig.13, it is shown that there are two speed curves in load 50N and 130N condition. By comparisons of simulation and experiment results, we can see that both are highly compatib

39、le.Fig.8 Three-phase current in load 50N conditionFig.9 Thrust force in load 50N conditionFig.10 Speed in load 50N conditionFig.11 Three-phase current in load 130N conditionFig.12 Thrust force in load 130N conditionFig.13 Speed in load 130N condition6 ConclusionsIn the paper, field-circuit coupling

40、method of the time-step finite element method and outer electric power circuit is utilized to analyze special load performances of lower speed of PMLSM with large ratio of the resistance to the inductance, large air gap and three-phase unbalance. Analysis results show that load performances of the P

41、MLSM in the heavy load condition are highly better than light load operation conditions, and operation current becomes lower with load increasing because of the large ratio of the resistance to the inductance and large air gap. Due to existence of detent force, the PMLSM mover speed fluctuates in th

42、e range of the synchronous speed. If the detent force of PMLSM with open loop control is reduced, the mover speed is quite close to synchronous speed.Refrerence1 Wang Xudong, Yuan Shiying, Jiao Liucheng, et al. 3-D analysis of electromagnetic field and performance in a permanent magnet linear synchr

43、onous motorC. IEEE International Electric Machines and Drives Conference, Cambridge, MA USA, 2001: 935-938.2 Bianchi N. Analytical computation of magnetic fields and thrusts in a tubular PM linear servomotorC. Conference Record-IAS Annual Meeting (IEEE Industry Applications Society), Rome, Italy, 20

44、00, 1: 21-28.3 Bon Gwan Gu, Kwanghee Nam. A vector control scheme for a PM linear synchronous motor in extended regionJ. IEEE Transactions on Industry Applications, 2003, 39(5): 1280-1286.4 Gore V C, Cruise R J, Landy C F. Considerations for an integrated transport system using linear synchronous mo

45、tors for ultra-deep level miningC. IEMD 99, Seattle, Washington, USA, 1999: 568-570.5 Jung In Soung, Hyun Dong Seok. Dynamic characteristics of PM linear synchronous motor driven by PWM inverter by finite element analysisJ. IEEE Transactions on Magnetics, 1999, 35(5): 3697-3699.6 Sang Yong Jung, Hyu

46、n Kyo Jung, Jang Sung Chun, et al. Dynamic characteristics of partially excited permanent magnet linear synchronous motor considering end-effectC. IEEE International Electric Machines and Drives Conference, Boston, USA, 2001: 508-515.7 Kwon Byung Il, Woo Kyung Il, Kim Duck Jin,et al. Finite element

47、analysis for dynamic characteristics of an inverter-fed PMLSM by a new moving mesh techniqueJ. IEEE Transactions on Magnetics, 2000,36(4): 1574-1577.8 Shangguan Xuanfeng, Li Qingfu, Yuan Shiying.Analysis on characteristics of permanent magnet linear synchronousmachines with large armature resistance

48、 and small reactance C. The Eighth International Conference on Electrical Machines and Systems, Nanjing, China, 2005, 1: 434-438.9 Tounzi A, Henneron T, LeMenach Y, et al. 3-D approaches to determine the end winding inductances of a permanent-magnet linear synchronous motorJ. IEEE Transactions on Ma

49、gnetics, 2004, 40(2): 758-761.10 Yamaguchi T, Kawase Y, Yoshida M, et al. 3-D finite element analysis of a linear induction motorJ. IEEE Transactions on Magnetics, 2001, 37(5): 3668-3671.11 In Soung Jung, Sang Baeck Yoon, Jang Ho Shim, et al. Analysis of forces in a short primary type and a short se

50、condary type permanent magnet linear synchronous motorJ. IEEE Transactions on Energy Conversion, 1999, 14(4): 1265-1270.文獻(xiàn)翻譯譯文正弦PWM 電壓源逆變器供電的永磁直線同步電機(jī)低速負(fù)載性能摘 要對(duì)于開環(huán)低速區(qū)由正弦PWM電壓源逆變器供電的永磁直線同步電機(jī)PMLSM而言，與工作在高速情況的PMLSM 負(fù)載性能不同，本文采用場(chǎng)路耦合時(shí)步有限元的方法研究PMLSM驅(qū)動(dòng)水平運(yùn)輸系統(tǒng)的兩種負(fù)載工況：輕載與重載。結(jié)果顯示，PMLSM 工作在重載情況下的負(fù)載性能較輕載優(yōu)，且電機(jī)的工作電流

51、隨著負(fù)載的增大而減小。仿真與實(shí)驗(yàn)結(jié)果驗(yàn)證了該方法的有效性及正確性。關(guān)鍵詞：永磁直線同步電機(jī)，負(fù)載性能，正弦PWM，電壓源逆變器，時(shí)步有限元法，場(chǎng)路耦合1 引言永磁直線同步電機(jī)PMLSM已廣泛應(yīng)用于多種領(lǐng)域，因?yàn)樵撾姍C(jī)具有高效性、高精度的控制性等特點(diǎn),從自動(dòng)化的運(yùn)輸操作系統(tǒng)到復(fù)雜精細(xì)的軍事設(shè)備都會(huì)運(yùn)用到它。然而，對(duì)于在較低速情況下的PMLSM的負(fù)載性能的研究是非常必要的，并且同步旋轉(zhuǎn)電機(jī)和PMLSM在高速情況下也有很多不同的特征。PMLSM在低速情況下因?yàn)橛卸喽行У臍鈮汉偷皖l率，電機(jī)具有抗電感能力強(qiáng)的根本特性。很多PMLSM具有這些特性，因?yàn)檫m用于PMLSM的轉(zhuǎn)速和頻率是有限的。通過(guò)文獻(xiàn)【5】

52、可以得出，適用于PMLSM的規(guī)格是一樣的。電機(jī)的運(yùn)轉(zhuǎn)頻率是6HZ，磁極距必須是30毫米。時(shí)步有限元分析法的研究為正弦PWM，電感是17.6mH，最大轉(zhuǎn)速是2m/s。根據(jù)文獻(xiàn)【7】顯示可知，模擬電壓是7V，頻率是3Hz，負(fù)載驅(qū)動(dòng)力是20N。電壓源逆變器供電的PMLSM的動(dòng)態(tài)特性的滯后性，是考慮了在合成鋁板和固體回收鐵中的渦電流，并通過(guò)分析時(shí)步有限元法和無(wú)線網(wǎng)絡(luò)技術(shù)得出的。在文獻(xiàn)【3】中，適于PMLSM的規(guī)格如下。電阻是5.2，電感是2.8mH，電機(jī)驅(qū)動(dòng)的轉(zhuǎn)速是0.9m/s。文獻(xiàn)【8】已經(jīng)呈現(xiàn)出PMLSM基于正弦交流電流源，如大電感和電阻率，的穩(wěn)態(tài)性能。但是，對(duì)于在低頻率下的有大的電阻率和電感、半

53、導(dǎo)體的SPWM逆變器操作，動(dòng)態(tài)性能指標(biāo)的研究在上述文獻(xiàn)中比擬缺乏。因此，研究電機(jī)在不同負(fù)載下的動(dòng)態(tài)性能是極其重要的。最近，通過(guò)精確的磁場(chǎng)分析，已經(jīng)研究提出了電機(jī)的動(dòng)態(tài)性能。其中的一種數(shù)學(xué)方法是基于有限元法的方法，它被越來(lái)越多的應(yīng)用于精確探討不對(duì)稱磁場(chǎng)的動(dòng)態(tài)性能。至于PMLSM，它有三相不平衡繞組、開放磁路、電阻率、電感系數(shù)、相位、諧波和電機(jī)電流。采用解析法和傳統(tǒng)的有限元法客觀地研究一個(gè)或兩個(gè)極點(diǎn)的周期邊界條件，是很困難的，另外考慮到連接外部SPWM變頻器和磁場(chǎng)的問(wèn)題，因此，本文就采用有限元分析法研究電機(jī)在不同負(fù)載的情況下，其暫態(tài)過(guò)程的性能，如：推力、移動(dòng)速度和繞組電流。由于PMLSM靠SPWM

54、電壓源逆變器供電，電機(jī)的電流是不知道的，并且電機(jī)的電壓還包括許多諧波分量，這就使有限元分析法不是很理想了。因此采用研究負(fù)荷性能時(shí)步有限元法和場(chǎng)耦合法就可以很好的研究該系統(tǒng)。這篇文章提出了使用時(shí)步有限元法和場(chǎng)耦合法研究電機(jī)在不同負(fù)荷情況下的性能。以下將會(huì)系統(tǒng)的講解，在第二局部中，將對(duì)永磁交流同步直線電機(jī)進(jìn)行描述。有限元模型在第三節(jié)中講解。在論文第四局部將會(huì)研究PMLSM在不同負(fù)載下的性能并進(jìn)行仿真和總結(jié)。在第五和第六局部，就總結(jié)實(shí)驗(yàn)結(jié)果并總結(jié)結(jié)論。2 物理分析模型這個(gè)模型主要是由三相繞組和核心擴(kuò)展插槽組成，其次是由永久性磁鐵和在鐵軛外表上別離出來(lái)的磁性組成。PMLSM的規(guī)格如下表1所示。其中含永

55、磁磁鐵磁化的漏磁量等。PMLSM的性能規(guī)格就在下面的表格中。PMLSM 規(guī)格表 型材 工程 材料和單位 相位 3 匝數(shù) 90主要 電樞材料 鐵 磁極距 39mm 槽距 13mm 主存材料 永久性磁鐵 寬度 27mm 其次 高度 7mm 長(zhǎng)度 120mm 鑲嵌 外表型 空隙 5mm 圖1 物理模型的方法建立的永磁直線型同步電機(jī)主要局部 2齒輪 3開槽 4絕緣磁鐵材料 5永磁鐵 6鐵軛3 PMLSM勵(lì)磁電路的數(shù)學(xué)模型把SPWM電壓源逆變器，電機(jī)邊緣效應(yīng)影響因素考慮進(jìn)去，采用勵(lì)磁電路方法計(jì)算電磁的暫態(tài)方程，解決向量電磁場(chǎng)的變化過(guò)程及電機(jī)的穩(wěn)態(tài)方程，由勵(lì)磁電路相結(jié)合的電磁場(chǎng)時(shí)步有限元方程，并說(shuō)明在電樞

56、繞組中的繞組電路電動(dòng)勢(shì)方程。瞬變場(chǎng)的控制方程，電磁場(chǎng)是可變的，其依據(jù)是麥克斯韋方程式。如方程式1可示：式中,Az向量電磁場(chǎng)中z軸方向的分量 Js電流密度Jm磁化密度磁導(dǎo)率在摘要中，2-d模型可以被分為三角元素構(gòu)成網(wǎng)孔。在運(yùn)用伽遼金法后，運(yùn)動(dòng)方程的分析模型為：式中，A未知的潛在向量電磁場(chǎng) I繞組電流 S,C,T系數(shù) G等效的矩陣磁化電流密度 在外磁場(chǎng)作用下，磁介質(zhì)磁化后出現(xiàn)的磁化電流要產(chǎn)生附加磁場(chǎng)。等效磁化法被用來(lái)處理永磁型場(chǎng)。磁化強(qiáng)度的符號(hào)是M0.由于電機(jī)較大的空隙特點(diǎn)，PMLSM的電阻和漏磁電抗沒(méi)有被無(wú)視。根據(jù)歐姆定律和法拉第電磁感應(yīng)定律，關(guān)于電動(dòng)勢(shì)和電壓的產(chǎn)生的三相繞組式如方程【4】：其中

57、 感應(yīng)電動(dòng)勢(shì) Ll自感系數(shù) R線圈電阻 U線圈電壓其中 N有效的線圈匝數(shù) B磁通密度 S1有效面積 S2有效面積適用于PMLSM的磁路和電路是不平衡的，從而固定連接器的電勢(shì)不等于零域上的電勢(shì)。因此電機(jī)的相位方程修改如下：其中 U0逆變器的輸出電壓 g0逆變器開關(guān)功能 Ud直流電壓采用麥克斯韋法計(jì)算PMLSM的電磁力，其中包含了所有種類的諧波成分。電機(jī)電磁力的正弦分量計(jì)算載于公式9。電機(jī)電磁力的垂直分量計(jì)算載于公式10。其中 L1繞組的有效長(zhǎng)度 L2積分長(zhǎng)度 Bxx軸方向的磁通密度 Byy軸方向的磁通密度 FT正弦方向上的電磁力 FN垂直方向上的電磁力PMLSM的運(yùn)動(dòng)方程如下：其中 m質(zhì)量 v速

58、度 FL負(fù)荷重力仿真結(jié)果仿真結(jié)果圖形如下。恒定電壓是30V，模塊頻率是2Hz，輕負(fù)載是50N，重負(fù)載是130N，電機(jī)額定同步速度是0.156m/s，這與PMLSM實(shí)驗(yàn)?zāi)Ｐ偷膮?shù)是保持一致的。從仿真結(jié)果我們可以得到，空間磁場(chǎng)的功能元素及外部電路的狀態(tài)作用。由于靠電壓逆變器提供電壓，外部條件可以忽略不計(jì)。圖2是在50N負(fù)載下的三相電流的仿真圖形。圖3是驅(qū)動(dòng)力。圖4是在50N負(fù)載下的速度。圖5圖7是在130N負(fù)載下的仿真圖形。從圖2和圖5，我們可以看出在50N負(fù)載下的三相電流比在130N負(fù)載情況下的要大。因?yàn)镻MLSM的磁路電樞繞組是開放的，不連續(xù)的。比擬圖3和圖7，我們可以看出PMLSM在130N

59、負(fù)載下的驅(qū)動(dòng)力更大。在圖4和圖7中可以看出，在130N負(fù)載的情況下，電機(jī)的性能更好，更穩(wěn)定。如果產(chǎn)生的適用于PMLSM的磁阻力減少，移動(dòng)速度根本上是接近同步速度的，因?yàn)橛性S多諧波，速度要完全相同是不可能的。a階段，b階段，c階段圖2 在50N負(fù)載下的三相電流圖3 在50N負(fù)載下的驅(qū)動(dòng)力圖4 在50N負(fù)載下不減少磁阻力時(shí)的速度圖5 在130N負(fù)載下的三相電流圖6 在130N負(fù)載下的驅(qū)動(dòng)力圖7 在130N負(fù)載下的速度實(shí)驗(yàn)結(jié)果電壓和電流是通過(guò)傳感器來(lái)檢測(cè)的。速度是通過(guò)E6B2型號(hào)的旋轉(zhuǎn)編碼器測(cè)得的，這個(gè)轉(zhuǎn)速可以轉(zhuǎn)化為電機(jī)的直線速度。數(shù)據(jù)采集系統(tǒng)可以通過(guò)Turbo C來(lái)編輯。圖8和圖11分別是在50N

60、和130N情況下的三相電流。圖9和圖12是分別在兩種負(fù)載下的驅(qū)動(dòng)力。圖10和圖13是在這兩種負(fù)載下的速度。通過(guò)仿真和實(shí)驗(yàn)結(jié)果，我們可以看出，這兩種情況都是可以的。圖8 在50N負(fù)載下的三相電流圖9 在50N負(fù)載下的驅(qū)動(dòng)力圖10 在50N負(fù)載下的速度圖11 在130N負(fù)載下的三相電流圖12 在130N負(fù)載下的驅(qū)動(dòng)力圖13 在130N負(fù)載下的速度總結(jié)在上述內(nèi)容中，勵(lì)磁電路耦合法中的時(shí)步有限元法和外部電路被用來(lái)分析專門適用于永磁交流同步電機(jī)在大阻力、大電感、大氣隙和三相不平衡的低速度的情況下的負(fù)載性能。分析結(jié)果外表，PMLSM在重載情況下的負(fù)載性能比輕載時(shí)好，并且電機(jī)的工作電流隨著負(fù)載的增大而減小。