Research On High-Response Drive Control Of AC Servo System Based On Non-Delay Feedback

High performance AC servo system, as an important drive part of high-speed and high-precision CNC machine tools, high-speed digital machines, integrated circuit IC manufacturing and packaging equipment, has been widely used in modern industry. With the higher standards of product, the performance demand of the AC servo is raised too. To obtain high-performance AC servo, it is necessary to do research on the advanced control strategy and control methods. The dissertation aims to do research on high-speed, high-response, high-precision and good-robustness AC servo system, and provide high performance servo drive system for advanced mechanical-electrical equipment.It is necessary to obtain high-precision, real-time current and position feedback to the closed-loop control of PMSM. Firstly, mathematics model of PMSM is established, discrete control model of AC servo with feedback delay is studied based on it, and it is proved that feedback delay affects the performance of AC servo and impairs dynamic characteristics and stable state precision in theory, which has laid foundations for the next study.To obtain the precise and real-time state variables of the PMSM control system position and current detection without delay are proposed. To the position feedback without delay, the detection plan with embedded sensor is designed, the new position subdivision technology is proposed and position detection without delay is realized; an integration of permanent magnet synchronous motor, combination hall magnetic ring and controller is realized based on the technology. To the current feedback without delay, current state observer is introduced; then its work timing is analyzed and the current detection without delay can be realized with experiment.In the PMSM vector control system with precision and high-response current, the order of system is degraded, which simplifies the plan of outer loop controller(speed control or position control) because it is not thinking about rotor's dynamic. To realize high-response and high-precision current control, the current loop of digital ac servo is studied: analyzing the influence of numeric voltage delay on current response and its control timing, calculating delay phase of PWM and compensating; introducing improved PWM, which improves the bus voltage utilization and current response performance.In order to realize high-speed and high-response velocity and position control, the mechanical loop of permanent magnet synchronous motors research is expanded. By analyzing the traditional velocity loop PI and IP control features, and summarizing their advantages and disadvantages, a PI-IP complex control with weighting factor is proposed, and the responsiveness and anti-jamming capability of the velocity loop is improved. Instruction feed forward control had been taken detailed research, simulation and analysis had been taken to testify the validity of command feed forward controller, which improved the tracking response performance for AC servo system; but the problem of poor anti-interference ability are still existed. Basing on this point, two-degree-of-freedom control method basing on the model is introduced, so the disturbance rejection characteristics and target tracking performance of the system effectively are improved, the influences of external interference on closed-loop system dynamic and static properties are reduced and rapid response and stable operation is realized.In order to realize the control parameter selection and optimization which completely disengage from hardware, a closed-loop simulation scheme which based on discrete motor model for AC servo system to be proposed and the digital closed-loop simulation platform is also realized. Based on the platform, combined with parameter optimization algorithm, the selection and optimization of control parameters is realized. Since the operation principle of closed-loop simulation platform is consistent with the actual system, it made simulation optimization control parameters closer to the actual value of the system. It could manifest shorten the software develop period.Finally, the integration permanent magnet AC servo system is developed, and the control strategy proposed in this dissertation is also tested by experiment, and the performance index for permanent magnet synchronous motor servo system is obtained at the same time. The experiment result illustrated that the high speed integration permanent magnet AC servo system possess the performance of high speed, high response and high reliability, it establishes a stability foundation for supplying high performance AC servo drive system to mechanical-electrical equipment.