Study On Direct Torque Control System Of Permanent Magnet Synchronous Motors

Compared with asynchronous motor,permanent magnet synchronous motor(PMSM)has the advantages of simple structure,reliable operation and easy maintenance,and is widely used in aerospace and industrial fields.Direct torque control(DTC)has been widely used since its successful application in the 1980 s.Especially with the development of DSP technology,the traditional direct torque control has been further optimized.In this paper,the direct torque control of permanent magnet synchronous motor based on duty cycle is studied.The main contents of this paper are as follows:(1)The development of PMSM and its classification,control strategy to introduce the direct torque control in the PMSM in several application strategies and current and future research hot spots were described.(2)The coordinate system commonly used in the analysis of the motor model is introduced and the CLARK transform and the PARK transformation are deduced.The mathematical model of the PMSM in different coordinate systems is described in detail and the torque control method is deduced.The control method of DTC is applied to the feasibility of PMSM.The voltage vector is defined according to the topology of the inverter and its effect on the motor torque and the stator flux is analyzed.(3)The simulation results show that the zero-voltage vector can reduce the torque ripple by comparing and analyzing the simulation results of the direct torque control based on PMSM using MATLAB / Simulink simulation software.(4)The direct torque control model of PMSM based on SVPWM is established.By comparing the simulation results,it is found that SVPWM not only maintain the dynamic characteristics of the system but also reduce the torque ripple of the system.(5)The hardware circuit design of PMSM motor control system with digital signal processor TMS320F28069 as the core is constructed.The main circuit parameter design,power device selection,bus voltage and phase current sampling circuit,drive circuit design and position signal detection circuit design are introduced in detail.And the keyboard input circuit design;and the software design of the system is given initially.