Single-phase Fault Tolerant Control Strategy Of Low Resolution Position Sensor For Permanent Magnet Synchronous Motor

The normal operation of the motor control system requires real-time acquisition of accurate rotor position and speed information.In practical applications,manufacturers often use installation position sensors to detect rotor information.However,in use,Hall position sensors may suffer structural damage due to various extreme usage environments,resulting in the control system being unable to obtain relevant parameters and unable to operate normally.Among many types of faults,single-phase Hall sensor faults are the most common.Therefore,in response to the above fault issues,this thesis proposes a single-phase fault tolerant control strategy based on low resolution position sensors to improve the reliability of the control system during operation.The main work of this paper is as follows:Firstly,the current research status of control strategies for three-phase permanent magnet synchronous motors was elaborated,and the research progress of fault-tolerant control strategies based on low resolution position sensors at home and abroad was introduced.Based on the analysis of PMSM,a structural model was built,and the overall control method of PMSM vector control system was discussed.The working principle of space vector pulse width modulation algorithm was also explained.Secondly,analyze and compare the rotor estimation methods for PMSM using three-phase low resolution Hall sensors.Based on the traditional average acceleration algorithm,a new acceleration algorithm is proposed by introducing speed and quadrature axis current,which to some extent improves the estimation accuracy of the traditional average acceleration algorithm.Build algorithm control simulation models for different estimation algorithms to verify the accuracy of the new algorithm,and provide a theoretical basis for the PMSM fault-tolerant control strategy method based on Hall sensor single-phase fault in the following text.Thirdly,in response to the issue of inaccurate rotor estimation algorithms under medium to high speed,rapid acceleration,and rapid deceleration conditions,an extended Kalman observer is introduced to establish an observation model based on the system’s output and input signals,thereby utilizing the extended Kalman observer for real-time estimation of rotor position and speed.And using a variable weight parameter regulator,a new low resolution sensor rotor position detection algorithm is proposed by combining the new acceleration algorithm with an extended Kalman filter under different motor speeds.Using a regulator to achieve adaptive control of PMSM,the estimation results of two types of estimation methods are coordinated and output,providing high-precision estimation algorithms for rotor information for the fault-tolerant control strategy in the following text.Fourthly,a new fault detection and fault-tolerant control method is proposed to address the issue of single-phase faults in Hall position sensors.We have built an experimental platform for a new fault-tolerant control system and used upper computer software to collect real-time test data.Through experiments,it has been verified that the control effect of the new fault-tolerant control algorithm is superior to traditional algorithms,improving the robustness and accuracy of the system.