Research On Sensorless Control Of Dual Three Phase Permanent Magnet Synchronous Motor

With the development of modern control theory and power electronics technology,high-power AC drive system has become a trend of development.Because of its high power density and high reliability,multi-phase motor can meet the requirements of high power and high reliability AC drive system.In this paper,some research methods of traditional three-phase motor are used for reference,and dual-three-phase motor which is similar to traditional three-phase motor is selected for research.Firstly,the application situation,mathematical modeling and control strategy of dual-three-phase permanent magnet synchronous motor(PMSM)are introduced.Considering that dual-three-phase permanent magnet synchronous motors are widely used in aerospace,electric vehicle,locomotive and ship with complex working conditions,and the reliability of motor drive system is very important,this paper analyses the common fault types and fault response measures in motor drive system,and the sensor faults with high fault incidence and great influence are studied in detail.By comparing the fault data of voltage/current sensor and position sensor,the importance of sensorless control as an emergency standby is illustrated.Secondly,the mathematical model of dual-three-phase PMSM is discussed.In order to realize the control algorithm,it is necessary to transform the rotating coordinates of the dual-three-phase PMSM.Therefore,the dual-three-phase PMSM model based on vector space decoupling and the mathematical model of PMSM based on double d-q coordinate transformation are analyzed,and the corresponding PWM control strategies and vector control comparison between the two coordinate transformations are analyzed.Thirdly,based on the mathematical model of dual-three-phase PMSM,the sensorless control of dual-three-phase PMSM is studied.The high frequency signal injection method is adopted in the low-speed section,and the sliding mode control strategy based on optimization is adopted in the high-speed section.By observing the rotational speed,the two methods are effectively combined to realize the sensorless control of dual-three-phase PMSM in the full speed range.It can maintain the basic safe operation and avoid the problem of reliability reduction caused by mechanical sensors under extreme conditions.Finally,the construction,software design and communication fault detection of the dual-three-phase PMSM drive and control experimental platform are introduced.A DSP implementation scheme of dual-three-phase PMSM based on dual d-q coordinate transformation control algorithm is designed,and the data communication part of the experimental platform is verified by experiments.