Mechanical Position Sensorless Control of Salient Pole PM Motor using High Frequency Test Current Injection-based Active Position Estimation

本课题的主要成果有：(1)提出了一种提高位置估计精度的方法：为了将位置估计误差降低到1/5，只需增加2位a /D转换器即可进行电流检测，同时需要增加10倍的电流检测数据数。通过仿真和实验验证了这一结果。(2)开发新的位置估计算法，降低电压源逆变器的直流电压限制：与传统的两相电流注入方法相比，只开发了单相电流注入方法。新的单相注入电流方法具有降低电压源型逆变器最大直流电压的优点。(3)将位置估计方法扩展到小凸度比的表面永磁永磁电机：扩展了位置估计方法，适用于小凸度比的表面永磁永磁电机。相比之下，传统的方法仅限于具有较大显着比的内嵌永磁永磁电机。由于新方法是基于磁饱和现象，因此可以估计转子的绝对位置。

Major results of this project are as follows :(1) Proposal of a method for improving position estimation accuracy :To reduce position estimation error to 1/5, only 2-bits increment of A/D converter is enough for current detection, meanwhile it is necessary to increase 10 times of current detection data number. This result was clarified by simulation and experimental tests.(2) Development of new position estimation algorithm to reduce DC voltage limitation of voltage source inverter :Only one-phase current injection method was newly developed, in contrast with conventional method that requires two-phase current injection. New one-phase current injection method has merit, which reduce maximum DC voltage in voltage-source inverter.(3) Expansion of position estimation method to surface permanent magnet PM motor with small saliency ratio :Position estimation method was expanded, which is applicable to surface permanent magnet PM motor with small saliency ratio. In contrast, conventional method was limited to interior permanent magnet PM motor with large saliency ratio. Since new method is based on magnetic saturation phenomenon, it is possible to estimate absolute rotor position.