| With the development of marine high power AC drive system and power electronic technology,and the improvement of human environmental protection consciousness,electric propulsion ships have been developed rapidly in 21st Century.This paper considers the ship Permanent Magnet Synchronous Motor(PMSM)sensorless control as the research subject.An in-depth study on the full speed range sensorless control technology is carried out.Firstly analyzes the structure of PMSM and its mathematical model in different coordinates,and the control strategy and sensorless control technologies are studied.The advantages and disadvantages of different control algorithms are analyzed.The back EMF integral method is influenced by the current sampling and inverter nonlinearity,which will cause integral drift problem in the practical application.This paper proposes an improved back EMF integral algorithm,which uses a low-pass filter with compensation instead of the integral.As a result,the problem of integral drift is solved effectively.Because the back EMF integral method in zero speed can’t be used,I/F control is used in zero speed.In order to ensure full load startup ability,the rotor preposition algorithm is studied,A smooth transition method is proposed to solve the problem of using two different algorithms in low speed and high speed.The simulation model of the full speed sensorless control is carried out under Matlab/Simulink environment,and the effectiveness of the algorithm is verified.Based on the previous results,the relation between sensorless control and the changes of motor resistance and inductance are analyzed.Furthermore,this paper studies the method of static measurement and online identification of motor parameters for further improvement of the performance.Finally,full speed range sensorless control system of a marine PMSM is built,experimental platform is designed.Parameters of the motor are measured;the dynamic static performance of full speed range is tested.The full speed range sensorless control of a marine PMSM is realized. |
