Open-circuit Fault Detection And Location Of Five-phase Open Winding PMSM Drive System

In recent years,with the rapid consumption of global fossil energy,the environmental pollution problem is becoming more and more prominent,which has become a very concerned topic.New energy vehicles,a new type of transportation,are developing rapidly,with electric energy as the main power,which greatly reduces the consumption of fossil energy.Continuous promotion of the development of electric vehicles will not only promote the rapid transformation of the automobile industry,but also the only way to sustainable development.The core of electric vehicle mainly includes: motor and motor drive system.Owing to the remarkable advantages of permanent magnet synchronous motor(PMSM,Permanent magnet synchronous motor),which makes it widely used in electric vehicles.Different from the traditional permanent magnet motor system,the open-winding structure motor is to open the neutral point connected with each phase stator winding,so that the inherent magnetic circuit characteristics of the motor have not changed,and the advantages of high power density and high efficiency still exist.It not only meets the need of fault-tolerant operation,but also makes the control of motor drive system more flexible.Although open-winding motor has many advantages,but the motor body,drive system and other failures may cause different degrees of damage to the motor.In order to ensure the reliability of the drive system of open-winding structure motor,it is of great significance to study the method of fault diagnosis.This paper has introduced the research background and significance of the subject,and the research status of open-circuit fault diagnosis of motor drive system at home and abroad.The related characteristics of the five-phase open-winding PMSM are analyzed,and the mathematical model of the abcde five-phase natural coordinate system and the dq rotating coordinate system is established.the control strategy of the motor drive system is studied: the current hysteresis PWM(Pulse Width Modulation)technology and the voltage space vector PWM technology based on the vector control method.An open-circuit fault of five-phase open-winding PMSM drive system is studied,including eight common open-circuit faults of inverter and stator winding: in order toeliminate the influence of motor operating condition on the system,the current normalization method is adopted,and two fault characteristic quantities are used to locate the fault by the current method.In the case of single-phase or two-phase bridge arm open-circuit and corresponding open-circuit fault in stator winding,the difference of zero-sequence voltage fundamental wave amplitude can not only judge the fault but also distinguish the two fault features.The above fault diagnosis method is simulated in the MATLAB/Simulink environment,and the motor drive system experimental platform is constructed with DSPTMS32F28335 as the main control chip,and the open-circuit fault diagnosis method is verified experimentally.