Research of the Hish Efficiency Induction Motor with Built-in Magnet

在本研究中，为了开发一种高性能的新型感应电机，我们研究了一种独特的内置磁体的感应电机，该磁体在其笼状转子中自由旋转。嵌入式磁感应电动机具有高转矩、高效率和可变功率因数等特点。参考其磁路模型，推导出内置磁感应电动机的等效电路，推导出目前尚不明确的等效电路。利用等效电路可以分析内置磁体电机的兴趣特性。针对这种内置磁感应电机存在起动转矩小、高速区域需要弱磁场控制的问题，研制了一种采用双笼式转子的内置磁感应电机。新的感应电机可以在小于额定扭矩60%的情况下启动。对双笼式转子内置磁感应电动机在不同频率下的效率特性进行了测量。出乎意料的是，双笼式转子磁体型感应电机在低频、低输出区域的效率低于市售机，但在高频、高负载区域，效率却大大高于其他感应电机。通过改进转子导体结构，可以克服这一缺点。由于内嵌式磁感应电动机的结构和运动非常复杂，磁场分析似乎是不可能的。在本研究中，我们首次设计了一种分析方法，成功地对其磁场进行了分析。

In this research, aiming at developing a new induction motor with high performance, we investigated a unique induction motor with built-in magnet that rotates freely in its caged rotor. The built-in magnet induction motor had interest characteristics of high torque, high efficiency and variable power factor. Referring to its magnetic circuit model, electric equivalent circuit that was not clear until now was derived for the built-in magnet induction motor. The interest characteristics of a built-in magnet motor could be analyzed by the equivalent circuit.Since this built-in magnet induction motor has a problems that starting torque is small and that field weakening control is necessary in high-speed area, a built-in magnet induction motor that adopted a double caged rotor was developed to solve this problem. The new induction motor was possible to start for less than 60% of a rating torque. Efficiency characteristic was measured for built-in magnet induction motor with double caged rotor in various frequencies. Against expectation, the efficiency of magnet type induction motor with double caged rotor was lower than that of marketing machine in low frequency, and low output area, but in high frequency and high load area, the efficiency became much higher than that of other induction motor. This weak point can be overcome by improving its conductor structure of rotor.The magnetic field analysis seemed impossible for the built-in magnet induction motor, because its structure and motion were very complicated. In this research we succeeded for the first time in its magnetic field analysis by devising analytical method.