Research On Fault Diagnosis And Fault-tolerant Control Of Position Sensors For Permanent Magnet Synchronous Motors

Permanent magnet synchronous motors are widely used in various fields because of their advantages of high efficiency and large power density.In the modern AC servo drive system,the accurate acquisition of the rotor position of the motor is an important part of the actual high-performance control.Among many position sensors,resolvers have the advantages of reliable structure,strong anti-interference ability,and being suitable for harsh environments,etc.,and are widely used in practice.However,the position sensor fails because of the influence of installation,environment and other factors,and it is easy to cause serious consequences such as the collapse of the control system.In order to ensure reliability,it is necessary to diagnose the position sensor failure and deal with the failure in time.Therefore,it is of great significance to study the fault diagnosis of the resolver in the permanent magnet synchronous motor drive system.The paper briefly discusses the Permanent Magnet Synchronous Motor(PMSM)vector control system,gives the basic mathematical model of PMSM and vector control method,explains the basic working principle of the resolver,introduces the process of generating the resolver excitation signal and the working principle of the resolver decoding chip,and gives the decoding algorithm and rotor position acquisition process.For the six types of common faults that may occur,such as amplitude imbalance,quadrature incompleteness,induced harmonics,signal offset,decoding angle offset,and jamming faults,the cause of the failure is analyzed and a failure model is constructed.The specific analysis is carried out on the rotor position angle double frequency fluctuations that occur in amplitude imbalance and incomplete orthogonal,the rotor position angle double and fourth frequency fluctuations that occur due to induced harmonics,and the rotor position angle fundamental frequency fluctuations that occur due to signal offset.The impact of different faults on the PMSM control system is discussed.After the fault,the rotor position angle is differentiated to obtain angular frequency components of different frequencies.The angular velocity component is the fault feature,and the discrete Fourier transform DFT amplitude extraction algorithm is used to extract the fault feature.The fault characteristic threshold is set to respond to different types of faults.On the basis of fault classification and diagnosis,for faults that can tolerate operation,the Kalman angle compensation algorithm is used to achieve real-time accurate acquisition of rotor position angle deviation after resolver failure.The rotor position deviation is compensated online in real time,the rotor position is accurately corrected,and the effectiveness of the fault-tolerant operation strategy is verified by simulation.On the d SPACE semi-physical experiment platform and the motor power experiment platform based on DSP28335,the angle-compensated fault-tolerant control strategy based on Kalman filtering method is experimentally verified.Effective fault-tolerant operation after resolver failure is realized.The effectiveness and feasibility of the angle-compensated fault-tolerant control scheme based on Kalman filtering method are verified.