Research On The High Performance PM AC Servo System And Its Novel Control Strategies

Along with the development of the manufacturing, as an important part of the digital control machine tool and the robot etc., PM AC servo system has been the important domain of the domestic and foreign research and application.Based on the comprehensively deep research on the PMSM's mathematic model and control theory, deep theory and substantially experimental research are made in this paper on the PMSM's torque observer, direct torque control, and sensorless control, and a high performance full digital PM AC servo system developed.In this paper, a torque observer based on time delay is presented. The conventional method's dependence on the parameters is overcome, and robust to the load disturbance. Its stability and validity are verified by both theoretical analysis and experimental results.A realization method of the PMSM direct torque control (DTC) is presented. The condition for steadiness of the MTPA operation above the base speed under the limitation of current, is deduced. Otherwise, it will lead to unsteadiness.A stator flux oriented control of the PMSM based on the SVPWM is presented, which takes full advantages of the direct torque control and vector control. It can realize the approximate continuous voltage vector, and decrease the torque ripple. The conclusion above is verified by the simulation and experiment results.A PMSM direct torque control based on the EKF is presented, which improves the accuracy of the stator flux, and is robust to the parameters change. Benefited from the EKF, it satisfies the rotor initial position of the DTC, is an essential sensorless control. Its validity is verified by the simulation results.A sensorless control method of the PMSM based on an adaptive sliding mode observer is presented, robust to the parameters change and load disturbance. Its convergence is verified by the Lyapunov theory. Conclusions above are verified by the simulation and experiment results.Grounded on the work above, a high performance full digital PM AC servo system based on the TMS320F240 is developed, and its monitor control system designed. Having the space vector PWM as the core of servo system, it has qualities such as multi-interface, wide speed range, and good dynamic and static performance.