Research On AC PMSM Servo System And Control Strategy

In the last several decades, the PMSM is rapidly implied on many kinds of drive systems, compared with other motors, the PMSM has many individual features. At the same time in view of the development trends of electric drives, the novel control strategies, which are aimed at the unsolved problems in the conventional PMSM servo system, are applied to drives, at this paper the theory and industrial application are studied.At first, the mathematical model of PMSM is presented which is based on the study of the physical and torque equation. Then the base simulation technique is presented.The decoupling controller of current loop is designed based on the internal model control., and the controller has only one adjustable parameter and design procedure is very simple. According to the relationship of the angle of the maximum torque and the q axis, the reluctance torque for salient PMSM is made full use of and the sator current amplitude is reduced by a large percentage, so that the system robustness is greatly increased. At the speed loop, this paper presents a single value model algorithmic control strategy which is the simplied form of normal model algorithmic control and has less computation work than the latter, so the real-time performance is very good.The conventional control strategies rest on accurate motor models and parameters and its system is very complex. In order to overcome this disadvantage, this paper combine fuzzy control with predictive control form the fuzzy predictive controller, which makes best use of the robustness of fuzzy control and the stability of predictive control, and the system has very little evern no stable error. At the same time design the switch control strategy based on fuzzy rules to decrease the switch disturbance.In order to decrease the cost, simplify the structure of the PMSM servo system and at the same has no effect on the system performance, this paper uses hall element as the position sensor ,which has very low solution but very low cost, and in order to realize sinusoidal current drive of PMSM, this paper presents a new rotor position estimator based on flux estimation. The theory and simulation results verify the correct of the control strategy.Combined with the Zhejiang province important science and technology research item "A novel intelligent numerical control machine tool" (the number is :001101061), a numerical control machine tool has been completed in august 2002, and it has been used in produce the part for nearly 10 months, and now the item has passed the check.