基于马鞍形磁场的永磁直线电机位置解算方法

针对直线电机转子位置检测低成本和较高精度的要求,提出了一种基于马鞍形磁场来获得位置信息的方法及实现过程。分析了永磁体表面的磁场分布特征,指出了利用马鞍形磁场分布曲线来解算位置信息的优点,提出了根据马鞍形磁场推算位置信息的算法流程:先测得错开相位的2条马鞍形曲线数据,划分为4个象限后建立数据库；位置检测时,运用区间搜索算法寻得实际角度所在区间；再根据精度要求,采用合适的插值算法计算得到待解算的角度。仿真结果表明:基于马鞍形磁场的位置解算,能较好地得到直线电机转子的位置信息。

A Method to Calculate the Position of Permanent Magnet Linear MotorBased on SaddleShaped Magnetic Field

Aiming at the low cost and high precision requirements of permanent magnet linear motor rotor position detection, a method based on saddleshaped magnetic field and the process to obtain position were presented. The magnetic field distribution characteristics of the permanent magnet surface were analyzed. The advantages of using the saddleshaped magnetic field distribution curve to obtain the position information were pointed out. The algorithm flow of estimating the position information based on the saddleshaped magnetic field waveform was proposed. First, two saddle curve data of the staggered phase were measured and the database was divided into four quadrants. Second, in the position detection, the interval search algorithm was used to find the best two sets of magnetic field intervals. Finally, according to the accuracy requirements, the appropriate interpolation algorithm was used to calculate the electrical angle. The simulation results showed that the position calculation based on the saddleshaped magnetic field could better meet the requirements of linear motor rotor position detection.