Research On High Performance Fault Tolerant System Of Permanent Magnet Synchronous Motor Based On Sliding Mode Observer

In order to cope with the oil crisis and environmental pollution,all countries in the world are vigorously developing new energy vehicles with electric drive mode to replace fuel vehicles.The permanent magnet synchronous motor vector control system is used as the driving method.The precision of permanent magnet synchronous motor control depends on the stability and accuracy of the feedback control link,that is,the accuracy of the speed sensor.In the case of complex working conditions and other reasons,the speed sensor inevitably fails,which affects the feedback control and threatens the safety of electric vehicles.Based on the problem of easy damage of speed sensor in electric vehicle control system,this paper designs a method for speed sensorless control after fault,and combines the control strategy after fault to propose a transition strategy from speed sensor to speed sensor.When the high-speed operation of the electric vehicle is realized in general,the speed sensor suddenly fails,and the system can automatically and smoothly transition to the speed sensorless control to ensure the safety of the driver and the vehicle system.Firstly,in order to make the speed sensor fail,the system can still operate stably.A new sliding mode observer based on the piecewise exponential function is designed.The state reconstruction algorithm is improved on the basis of the original traditional observer to weaken the existence of the estimation method.Earthquake and defects to ensure the safety of the entire vehicle after the failure.Secondly,for the switching impact problem at fault,the transition algorithm between the two control methods is optimized,and the curve overshooting strategy is proposed,instead of direct switching and simple weight function switching,using the equal area rule for the system state in the transition.The missing part is area compensated to ensure the smooth and stable transition process.In this paper,through the matlab/simulink simulation platform,the fault-time switching algorithm and the fault-free sensorless algorithm are simulated and verified.The experimental platform is built to verify the theory and simulation.Both the simulation and the experiment verify the feasibility of the designed algorithm.