Research On Reduced Order Fault-tolerant Control Of Permanent Magnet Synchronous Motor Based On Sliding Mode Observer

Because of the advantages of high output efficiency and good dynamic performance,polyphase motor has become a research hotspot in the field of motor speed regulation,while six phase motor has similar control technology with threephase motor,so it has become the research focus in the field of high reliability.For motor fault-tolerant control technology,reduced dimension fault-tolerant has higher control accuracy than traditional software fault-tolerant;At the same time,the sensorless algorithm can reduce the system volume and cost.Therefore,this dissertation will take the symmetrical six phase as the research object,and study the sensorless detection technology and reduced dimension fault-tolerant control technology based on the new sliding mode observer algorithm.The topic has good theoretical research significance and practical value.The literature on polyphase motor drive system and related technologies at home and abroad are queried,and the research status related to position sensorless control technology and fault-tolerant control technology is analyzed,which lays a solid foundation for the next theoretical research.The mathematical model of six phase motor in the transformed coordinate system is given.For one-phase and two-phase open circuit faults of the motor,the reduced dimension mathematical model of the motor and the general reduced dimension transformation matrix are derived.A new sliding mode observer algorithm is proposed,which can extract the motor speed and rotor position information from the constructed sliding mode surface observation equation,and calculate the corresponding sliding mode surface correlation coefficient by Lyapunov function,so as to ensure the position detection accuracy.The simulation platform is built to verify the new sliding mode observer algorithm.The reduced dimension fault-tolerant control method is adopted.In case of motor open circuit fault,the amplitude and phase of residual phase current in case of motor one-phase and two-phase fault are recalculated with the constant magnetomotive force as the constraint condition and the maximum output torque as the goal.The simulation research shows that the reduced dimension fault-tolerant control technology is feasible.The new sliding mode observer algorithm and reduced dimension fault-tolerant control technology are applied to the symmetrical six phase PMSM system.The system design,experimental platform construction and experimental research are carried out.The results show that the position free detection technology has high position detection accuracy,and the reduced dimension fault-tolerant control technology has the characteristics of high control accuracy and strong fault-tolerant ability.