New Concepts for AC Motor Drives Requiring a Wide Speed Range

9510115 LiPO在主轴驱动器、钢铁厂和造纸机械等电机驱动应用中的一个常见要求是在较宽的速度范围内保持恒定姿态。恒功率运行在电力牵引领域尤其重要，该领域涵盖从机车到电动汽车的广泛应用。目前，使用弱磁技术来扩大传统设计的交流电机的速度范围，但随着恒功率运行所需的速度范围增加到正常(或“额定”)速度的两倍以上，感应电机和永磁式电机的电机尺寸和重量都急剧增加。在该项目中，提出了一套综合的分析、仿真、设计和实验方案，以开发具有扩展“恒功率”弱磁范围的交流感应和同步电机，而不需要过大的电机。这两种电机的定子绕组的变极都是通过仅使用传统的脉宽调制逆变器对馈入特殊设计的定子绕组相的电流进行适当控制来实现的。因此，定子变极机构不一定要引入任何额外的开关、承包商或固态(或无源)部件来完成其任务。实现扩大弱磁范围的目标将通过定子和转子设计的创新概念来实现，这将使这些新电机的尺寸和重量大约是目前用于此相同目的的传统交流电机的30%至50%。***

9510115 Lipo A frequent requirement in motor drive applications such as spindle drives, steel plants, and paper making machinery is to operate at constant poser over a wide speed range. Constant power operation is particularly important in the field of electric traction which covers a wide range of applications ranging from locomotives to electric vehicles. At present, field weakening techniques are used to widen the speed range of ac machines of conventional design, but as the desired speed range for constant power operation increases beyond twice the normal (or "rated") speed, the motor size and weight increases dramatically for both induction and permanent magnet type machines. In the proposed project, a comprehensive analytical, simulation, design and experimental program is set forth to develop ac induction and synchronous machines which possess the capability of an extended "constant power" field weakening range without need for an oversized machine. Pole changing of the stator winding of both types of machines is accomplished by proper control of the currents fed to the phases of a specially designed stator winding using only conventional pulse width modulated inverters. Hence, the stator pole changing mechanism does not necessarily introduce any additional switches, contractors or solid state (or passive) components to achieve its task. The goal of achieving extended field weakening range will be accomplished by means of innovative concepts of stator and rotor design which will enable these new machines to be roughly 30 to 50% the size and weight of conventional ac machines presently used for this same purpose. ***