Fault Diagnosis Of General Permanent Magnet Synchronous Motor Speed Regulation System Research On Motion Compensation Method

Permanent magnet synchronous motor(PMSM)is widely used in high performance servo system as the terminal execution unit of various automatic equipment because of its outstanding advantages such as high power density,small size and good heat dissipation performance.However,as a typical mechatronic system,permanent magnet synchronous motor servo driver often has many faults in the practical engineering application,which affect its normal operation.One of the most common and important faults is the communication fault of the encoder unit,which usually causes the motor to run unsteadily,jitter and even force the servo driver to shut down.In addition,the variety of coder brands on the market makes it more difficult to diagnose and rectify such faults.So this paper mainly focuses on multifarious absolute encoder communication fault.By establishing a universal adaptive fault detection and motion Prediction mechanism,it realizes the automatic identification,proactive detection and online motion compensation of common encoder faults,which is expected to improve the fault diagnosis and fault tolerance ability of servo system.Specific research contents are as follows:Firstly,the basic principle and structure of permanent magnet synchronous motor are deeply investigated and analyzed,its mathematical model is established,and the hardware and software development of embedded permanent magnet synchronous motor servo drive system based on DSP2812 processor and FPGA technology is completed according to the design requirements.Hardware design includes rectification and inversion unit,minimum system unit of DSP,minimum system unit of FPGA,power unit,current sampling unit,absolute encoder unit and panel display unit.Software design includes main program unit,control algorithm unit,SVPWM unit,and keys-display unit,etc.In view of the variety of absolute encoders on the market,in order to realize the generality of the servo drive system designed for fault diagnosis of different encoders,this paper makes a concrete analysis and comparison of the common coder protocol formats such as Domochuan,Nikon,HEIDENHAIN,BISS-C,etc.,and implements the function of automatic recognition of type coders with FPGA.On this basis,by simulating the complex and severe electromagnetic interference environment often encountered in the actual use of servo drivers,typical EMC testing methods such as ESDand EFT are adopted.And in this test environment,when the faults occurs,it is diagnosed according to the specific protocol formats of various encoders,thus establishing a fault diagnosis system.Therefor,an adaptive encoder communication fault diagnosis mechanism for data format errors,CRC check errors,data missing and other faults is established,and this method is verified by experiments.In order to ensure that the motor can still run smoothly when the encoder fails,an online state prediction and motion compensation method based on Kalman filter is designed and developed in this paper.Firstly,the speed loop and current loop of permanent magnet synchronous motor are modeled and the controller is designed.At the same time,the computer theory of motor speed is introduced in detail.The feedback value of motor speed is obtained when the fault occurs,and the causes of motor speed stall and motor jitter are deduced.On this fundamental,Kalman filtering algorithm is used to realize the accurate prediction of the actual motor speed when the fault occurs.The online motion compensation of the motor speed is realized by comparing the actual speed with the expected speed.The correctness and effectiveness of the algorithm are verified by the simulation experiment of Matlab.