1、中文 3000字 文献翻译原文 LOAD PERFORMANCE OF PMLSM IN LOWER SPEED REGION FED BY SINUOIDAL PWM INVERTER Si Jikai1,2 Chen Hao1 Wang Xudong2 Yuan Shiying2 Shangguan Xuanfeng2 （ 1. ChinaUniversity of Mining and Technology Xuzhou 221008 China 2. Henan Polytechnic University Jiaozuo 454000 China） ABSTRACT For the
2、permanent magnet 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
3、method to investigate 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 operatio
4、n current becomes 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 method
5、 1 Introduction The 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 necessa
6、ry that load performance 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 resist
7、ance to inductance 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
8、 were as follow. 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 switching logic of PWM inverter. In the Ref.6, the authors presented the dyn
9、amic characteristics of partially excited permanent magnet linear synchronous motor considering end-effect. The starting and control characteristics related to the capability in PMLSM driving were investigated. The specifications of the motor were as follow. The resistance was 7.6 of sample A, the i
10、nductance was 17.6mH, the maximum speed was 2m/s. As the Ref.7shown, the simulation condition was 7V, 3Hz and load thrust was 20N. The dynamic characteristics of the hysteresis current controlled inverter-fed PMLSM with the conductive sheet secondary was analyzed through the time-step finite element
11、 method and moving mesh technique, which considering eddy-currents in the secondary aluminum sheet and solid back iron. In the Ref.3, the specifications of PMLSM were as follows. The resistance was 5.2, the inductance was 2.8mH,the motor was running at 0.9m/s. Ref.8 had presented the steady-state pe
12、rformance 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 and large
13、r 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 accurate
14、 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 magnetic ci
15、rcuit9-11. 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 conventi
16、onal 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 speed and
17、 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 method and c
18、oupling 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 performances in t
19、wo 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 presented. L
20、astly, in section some conclusions are drawn. 2 Analysis model The 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 and 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 specifications
