Development Of PMSM Control System Experimental Platform And Application Research Of Sliding Mode Control

The direct torque control (DTC) has merits of simple structure, fast response, and strong robustness etc. Along with the theory that DTC strategy applying to permanent magnet synchronous machine (PMSM) has been solved, also as the superior performance of the PMSM, the PMSM DTC control strategy has received increasing attentions. This thesis will carry on simulation and experimental study on the performance improvement of the PMSM DTC.The classical DTC technology is introduced in this thesis, the simulation model of PMSM DTC based on MATLAB/Simulink is implemented, and the simulation research is carried out. The fully digital PMSM DTC experimental platform based on TMS320LF2407 is implemented, the intelligent power module (IPM) and Hall sensors of current and voltage are adopted, which increase the reliability and sampling precision of the system. The whole control program, which is based on the hardware with TMS320LF2407 as the core, is developed by adopting the mixed procedure of assembly and C language. And the function is implemented, which includes the stator phase current sampling, the DTC algorithm and the serial communication. The space voltage vector choice table is designed on the condition of low level effective driving signal of IPM and including the zero vector. The open loop and closed loop no-load experiment is proceed in the experimental platform, and the feasibility of system design scheme is confirmed. This system has merits of simple structure, good robustness, fast dynamic response of torque and speed. But this system has the greater ripples of the flux linkage and electromagnetic torque, the inconstant turn-on frequency of the inverter, and the system control performance needs to further improve.The sliding mode variable structure control (SMVSC) has the characteristics of fast response, less over-shoot, strong robustness and anti-disturbance etc, so it is suitable for PMSM which is a high-order, nonlinear and strong coupling multi-variable system. Whereas the classical DTC has the greater ripples of the flux linkage and electromagnetic torque, the inconstant switching frequency of the inverter, the SMVSC strategy is introduced into the PMSM DTC in this paper, and a PMSM SMVSC DTC system based on TMS320LF2407 is implemented. Simulation and experiment results show that the proposed SMVSC DTC system has low ripples of the electromagnetic torque and flux linkage, fast response and good robustness to varying parameters, and constant turn-on frequency of the inverter, and the system control performance is improved greatly comparing with the classical DTC.