Research On Elevator Traction Machine Control System Based On Direct Torque

The installation of elevator is an important way to improve the living quality of residents in old residential areas,which makes the elevator driving motors more and more diversified.Permanent magnet synchronous motor(PMSM)is more and more used in elevator traction system with its unique performance.In order to make it better improve the ride comfort in the process of elevator operation,the selection and improvement of control methods is also particularly important.Firstly,some basic structures and mathematical models of permanent magnet synchronous motor are discussed in detail,and the coordinate transformation of PMSM mathematical model is described Based on the theory of direct torque control(DTC),the simulation model of the direct torque control(PMSM DTC)control system of permanent magnet synchronous motor is established by Matlab/Simulink software.The results show that the system has the advantages of fast dynamic response,strong robustness and simple structure.The elevator has good self-regulation ability,but the operation of the elevator is unstable after disturbance.It is essential to analyze and talk over the particulars of direct torque control system,that is,the cause of excessive torque ripple.Secondly,in order to optimize the PMSM-DTC control system,the traditional six sectors were subdivided into twelve sectors,which resulted in large torque pulsation and asymmetric flux increment at sector boundaries.A resistance estimator was designed for the deviation between the observed value and the actual value of torque and flux caused by the change of stator resistance of the motor at low speed.A resistance estimator that uses current to measure changes in stator resistance of a motor in real time,so as to achieve reduce the flux and torque error in the operation of the system and suppress the torque ripple.Finally,in the stator flux observation,in addition to the calculation error of stator resistance,there is also the problem of DC bias.In the improvement of stator flux observation,the specific method is to use an improved integrator with limited amplitude,and use the fuzzy control method to compensate the flux angle,so as to make the observation of stator flux more accurate.The performance of pmsm-dtc system for elevator in low speed is further improved and improved.The unique structure of PMSM and the improved DTC system meet the safety,reliability,stability,low noise and so on.Figure[63]Table[9]reference[66]...