Sensorless Control Of The Tubular Permanent Magnet Linear Synchronous Motor In Full Speed Range

In the field of oil pumping units,in order to improve the situation of oil exchange by electricity for a long time in China,the academic and industrial circles have attracted wide attention.Tubular Permanent Magnet Linear Synchronous Motor(TPMLSM)is the core component of a new type of pumping unit currently under study,which has energy-saving advantages in the field of oil extraction application.In order to eliminate the influence of harsh environment in oil field on the installation and use of position sensor,the research on Positionfree control of cylindrical linear permanent magnet synchronous motor is very meaningful.In this paper,the traditional sensorless control algorithm is improved and applied to the tubular permanent magnet linear synchronous motor,and the advantages of the improved algorithm are verified by simulation and experiment.The main contents of this paper are as follows:1.An improved pulse high-frequency injection method is proposed.By using the secondorder low-pass filter and the proposed PI parameter tuning method,the speed and position tracking accuracy are improved.2.An improved sliding mode observation method is proposed.By improving the sliding mode observation control rate function,the tracking errors of speed and position are effectively reduced,and the tracking chattering is reduced.3.An improved composite control algorithm based on weighted function is proposed.The improved pulse high frequency injection method is used in low speed section,the improved sliding mode observation method is used in middle and high speed section,and the weighted function is used in the middle speed switching section to switch them.A method to eliminate the influence of high frequency signal is proposed for the speed switching process,which effectively improves the tracking performance in the whole speed range Tracking accuracy.4.The experimental platform of tubular permanent magnet linear synchronous motor is built to test the proposed control method.The experimental results show that the improved weighted function composite control method has the optimal performance.