Fundamental Research on Design Consideration of High Speed Induction Motor and its Speed Sensorless Vector Control at Maximum Efficiency for Electric Vehicles

本研究的目的之一，是分析和找出转子线棒间的交叉路径电阻、偏斜系数和集肤效应对宽调速范围电动车用逆变器供电的高速笼型异步电动机转子槽设计的影响。本文在考虑转子集肤效应和空间谐波的三相异步电动机的理论和仿真结果的基础上，讨论了梯形转子线棒在不同横径电阻值和扭斜系数下的异步电动机驱动性能。它已经得到的等效转子电阻和漏抗的变化与交叉路径电阻，空间谐波，和偏斜因子的各种值的基本电源频率。最后，本文讨论了宽调速范围内逆变器供电的高速笼型异步电动机的梯形转子槽形状，以获得良好的效率和转矩性能，并提出了宽调速范围内无速度传感器直接磁场定向控制异步电动机的高效转子磁链控制方法。所提出的系统是通过使用自适应转子磁链观测器。实验和仿真结果表明了这一点。该系统在稳态时的效率远上级转子磁链恒定的系统，并且在瞬态时电机的速度响应没有下降。最后，研究表明定子电压偏移对无位置传感器直接磁场定向感应电机低速特性的影响是显著的。此外，还提出了一种补偿定子电压偏移的方法。仿真和实验验证了该方法的有效性。

In this research, one of the purpose of our works is to analyze and find out the effects of crosspath resistance between rotor bars, skew factor and skin effects on the rotor slot design of inverter-fed high speed cage induction motor driving for wide speed range of electric vehcles. The performance of the induction motor drives for various values of crosspath resistance, and skew factor with the trapezoidal rotor bar have been discussed on the basis of theoretical and simulationresults of a three phase induction motor taking into account the skin effect of the rotor and the space harmonics. It has been obtained that the equivalent rotor resistance and leakage reactance change with crosspath resistance, the space harmonics, and the skew factor for various values of the fundamental supply frequency. And finally, we discussed the rotor slot-shape of the trapezoidal rotor slot for good efficiency and torque performance of the inverter-fed high speed cage induction motor for wide speed range of electric vehcles.The other purpose of this research is to suggest the high efficiency rotor flux control of the speed sensor less direct-field-oriented controlled induction motor operating at high efficiency for wide speed range of electric vehcles. The proposed system was achieved by using an adaptive rotor flux observer. This was shown by experimental and simulation results. The proposed system was far superior to one with a constant rated rotor flux with regard to efficiency in the steady state, and it's motor speed response showed no degradation in the transient state.Finally, It has been made clear that the stator voltage offset influences the low speed characteristics of the sensorless direct-field- oriented induction motor drives significantly. Furthermore, a method of compensating the stator voltage offset has been proposed. The validity of the proposed method has been verified by the simulation and experiment.