| Along with the fast development of power electronics, micro-computers, rare earth permanent magnet materials and control theory, permanent magnet synchronous motor(PMSM)has been widely applied in motion control system of medium or low capacity. PMSM has become the developing direction of servo drive in servo drive field, and gradually takes the place of DC motor and step motor. However, permanent magnet synchronous servo system was influenced by the change of motor parameters, load disturbance etc. In order to obtain permanent magnet synchronous servo system with high performance and wide speed range, and to make the system posses better flexibility and strengthen anti-jamming, new control strategies and control measures should be studied and applied in the system. This paper is aiming at high performance, wide speed range permanent magnet synchronous servo system, and its main contents as follows. The PMSM control systems respectively using the control strategies of the vector control technique and the direct torque control technique (DTC) are analyzed systematically. They are compared in principle and control capability when using the two control strategies. The analyses shows that the parameters in d and q axe are decoupling, the torque control characteristic is linear, output torque steady, the speed range wide when the vector control technique is applied in motion control system. To meet the demand of servo drive system, the vector control technique is chosen as the control strategy of permanent magnet synchronous servo system. The torque control of motor is actually current control of d and q axe. Four current control methods of PMSM vector control are discussed in detail, and their characteristics of torque control, power factor, current control etc are studied. It suggests that the rotor field-orientation vector control of id=0 can be chosen, in view of the surface mounted PMSM used in the item. Based on automation theory, the configuration and mathematical model of all parts of permanent magnet synchronous servo system were analyzed carefully. The three loops of the system were designed with the help of engineering design method of automation system regulator. The simulation of the system was taken, and the stability of the system was studied. The relationship of dynamic performance of the system vs. parameters of system regulator was analyzed in detail, joined with the influence of load and parameters change on all the pats of the system, and the measures taken to cope with this problem were studied. A rotor preliminary orientation of PMSM was put forward and realized, which ensured the realization of servo system vector control. The factors that influence on servo system current loop were analyzed, in which, the zero drift of current loop affected low speed performance of servo system, and the electromotive force (EMF) of motor affected response performance at high speed range. In order to improve low speed performance, the parts of the current loop needed to be carefully adjusted one by one. With increasing the proportional and integral factor of current regulator and increasing modulation ratio of PWM inverter, the current tracking performance at high speed range can be obviously improved. Because of the dynamic overshoot of current tracking response when the proportional and integral factor was increased, current differential negative feedback was adopted to current loop, and both numerical simulation and experiment showed the function in restraining current overshoot. To obtain faster speed response, the overshoot of PI regulators, which were designed according to automation principle, was almost inevitable. And in practice, we have to adjust them greatly. In this paper, a new method, the Linear State Feedback LQSF, was adopted to design speed regulator of permanent magnet synchronous servo system. The Bang-Bang control was applied to control speed in the period of regulator saturation, aiming at speed regulator saturation in speed step process. The valves of regulator configuration transform wer...
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