Research On Low Speed Performance Of Permanent Magnet Synchronous Machine Direct Torque Control

The Permanent Magnet Synchronous Machine (PMSM) has come to the drive system developers' attention for their merits such as low volume, high power density, high efficiency and simple maintenance. In order to enhance the performance of PMSM drive system, direct torque control (DTC) method with simple structure and fast dynamic response has been applied. On the basis of analyzing and concluding PMSM DTC theory, stator flux observers have been studied deeply in the paper, which set the foundation of improving the low speed performance of PMSM DTC drive system.The theory of PMSM DTC method has been analyzed from the mathematics model of PMSM. Two control strategies that are based on switch table and space vector PWM DTC and their simulation analyze are introduced on basis of the PMSM DTC model.Moreover, this paper gives the detail analyze of key points in PMSM DTC's low speed performance and yields their effective solution. the estimation method of stator flux have been studied. A modified integrator is applied to stator flux observer of PMSM DTC.With the help of MATLAB/Simulink tools,it has been set up that each part of PMSM control system model and simulation. All the simulation result justifies the effective of the solutions.At last, the implementation of the full-digital PMSM DTC is designed based on the DSP TMS320F2812, in the meantime the part of hardware and the part of software are given in detail.