The currents of phase A and phase B are bigger due to small mutual inductances. To phase C, the fundamental component is 13.15A, which is also bigger than that of equivalent circuit method. The error is 13.3%. Although, the thrust ripple is still bigger, it is smaller than that of symmetrical current source.  Fig.10 shows the dynamic velocity of LIM at load 300N. The static velocity is 0.7m/s, so the slip is 0.4. As shown in Fig.6, the thrust force is 296N at the same slip. Apparently, the results of two method are almost same. During the starting procedure, the currents  not decrease rapidly as normal LIM, only have slight change.   The height of yoke is much high because the lamination is assembled by bolt. If it can be assembled by welding method, the height of yoke can be decreased as much. According to former analysis, the primary height can be reduced to 6cm. Fig.11 shows the obtained locked thrust force and three phase currents.  Apparently, the thrust force and three phase currents almost kept constant, therefore, the magnetic field in yoke is smaller than saturation value.  The thrust force of different tooth width is also calcuated, shown in Fig.12. Apparently, when the tooth width is equal to 3mm, the performance of LIM becomes worse because the thrust force rapidly decreases and the current also increases. It is caused by magnetic field saturation. After the tooth width is over than 4mm, the thrust force and current almost keep constant.   Furthermore, compared with tooth width 4mm and 5mm, the thrust force of former is a little higher and its current is also smaller. Of course, the current density is also slightly improved due to smaller slot area.    It should be noticed, the tooth width should be bigger thannormal LIM with power supply. The reason is big flux densitydue to full voltage and low frequency. Of course, the currentdensity is also affected by tooth width.  The prototype is made and installed in a 8-layers stereo garage to drive the crossbeam in lifting platform. Fig.13(a) and Fig.13(b) shows LIM primary and lifting platform. The 8-layers stereo garage, shown in Fig.13(c), has good performance and already has been operating for two years till now.   At a test platform, the LIM is locked and supplied with 380V, 11.5Hz three phase voltage, and then the locked thrust force can be measured. Table 1 lists measured value of six LIMs. As it can be seen, the average value of current is 12.2A, and the average thrust force is 702N. Apparently, the measured current and thrust force are close to those of predicted values. The small error may be caused by the installation of processing precision.   TABLE 1  MEASURED THRUST FORCE Motor Number Current (A) Thrust force (N) 1 12.6 686 2 12.8 696 3 11.5 725 4 11.5 696 5 13 725 6 11.8 686   In stereo garage, the given maximum value of velocity, accelerator and decelerator are 0.8m/s, 0.4m/s2 and 0.8m/s2, respectively. That is to say, the whole time is 5s. When the crossbeam takes or stores the car carrying plate (without car), the measured maximum velocity, voltage, frequency and current are 317V, 11.6Hz and 9A respectively. The corresponding velocity response curves are shown in Fig.14. Apparently, the velocity of crossbeam arrives 0.8m/s at no load, just crossbeam moving. However, it decreases a little when the crossbeam moves with car carrying plate. Of course, the thrust force still can be improved to reach 0.8m/s, especially to taking or storing cars.  The LIMs are a strong candidate for huge, fast and intelligent stereo garage. In stereo garage, they can be mounted below the crossbeam on lifting platform and in the lognitudinal moving mechanism on top of stereo garage. The crossbeam can take or store the cars to parking spaces, and lognitudinal moving mechanism can quickly move the lifting platform in longitudinal direction. Therefore, the car parking capacity is significantly improved. In the same time, the car access rapidity can be guaranteed without any intermediate conversion devices.  This paper designs the LIM with low frequency  for  stereo garage, which can be adopted to drive not only the crossbeam, but also lognitudinal moving mechanism. By analytical equivalent circuit method, the static performance and the influences of structure parameters of LIM are investigated. The predicted results are validated by those of FE method and measured results of prototype. For this LIM, the tooth width apparently affects the thrust force due to relative bigger flux density compared with normal LIM with power supply. Therefore, the tooth width cannot be so small as that of normal LIM. The designed LIMs are successfully applied in the car lifting platform of 8-layers stereo garage, and the lognitudinal moving mechanism in other stereo garage. 立体车库电动机研究英文文献和中文翻译(3):http://www.youerw.com/fanyi/lunwen_34847.html