Sensorless Control And Experimental Study Of Permanent Magnet Motor Based On Novel Sliding Mode Observer

Today,the Internet and industry are infiltrating into each other,and the "intelligent industry" is coming.The most widely used permanent magnet synchronous motor control system in industry must have better performance.The traditional permanent magnet synchronous motor control system with mechanical sensors is susceptible to the influence of the external environment,and has been gradually eliminated by the " intelligent industry" era,and replaced by a high-performance,high-precision permanent magnet synchronous motor sensorless control system.Therefore,this thesis studies the sensorless control system of permanent magnet synchronous motor based on a novel sliding mode observer.First,the background and significance of the research on sensorless control of permanent magnet synchronous motors and their current development status are explained.In addition,the basic principles of vector control of permanent magnet synchronous motors are analyzed in depth.At the same time,the principle of sliding mode variable structure control and its problems are briefly described.Secondly,since the sensorless control system based on the traditional sliding mode observer has the problems of chattering and low observation accuracy,in this thesis,the switching function in the traditional sliding mode observer is replaced by a sinusoidal saturation function with a variable boundary layer.Sliding mode gain was changed to fuzzy adaptive sliding mode gain,and the complex-coefficient filter and Kalman filter was used to replace the low-pass filter,and the observed back-EMF was fed back to the state equation.A novel sliding mode observer was constructed to suppress the occurrence of chattering and improves observation accuracy.In the rotor position and speed estimation,a fractional phase-locked loop technology is used to further improve the estimation accuracy.Finally,in order to verify the actual effect of the novel sliding mode observer constructed in this thesis.Based on the principle of sensorless control system based on a novel sliding mode observer,the hardware design and software design are done.The hardware design is based on the DSP28335 main control chip.The power circuit,three-phase current and voltage acquisition circuit,drive and protection circuit,and communication circuit are designed.The software design mainly develops the system main program and interrupt service program on the CCS platform.Finally,a 4-pole 200 W permanent magnet synchronous motor is used as the control object,and the effectiveness of the novel sliding mode observer method proposed in this paper is verified by experiments.