| When multiple-motor system is running, the load torque of the motors always change because of the change of operating mode and the disturbance of stochastic load. Rotation speed of the motor would be disturbed directly by the change of the load torque. At the same time, the load torque of multiple-motor system changes regularly in different operating modes. And the change of load is always related with dynamics characteristic of system. For example, in vibration machine with dual-motor drives, the change of motor load is related with phase difference of two eccentric rotators. So if the rule of motor loads can be found, the mechanical system and motors system can be designed and controlled better. But restricted by actual sensor technique, it's very difficult to identify load torque directly. On the basis of this problem, this paper investigates the relation between motor stator current and load torque through the research of the relation in the process of running of the motor. That is, the change rule of load and the load itself can be forecasted through the stator current. And stator current can be measured easily. Using fuzzy control theory and the relation between stator current and slip ratio, this paper also proposes two control methods, fuzzy controller with rotation speed sensor and fuzzy controller without rotation speed sensor, to control motor rotation speed. The control method is validated by simulation result.The following are the main contents of this paper:(1) The effective identification method is proposed and hardware circuit is desighed to identify motor parameters, such as phase difference of voltage and current, the max breadth of voltage and current, rotation speed and angular displacement of the motor.(2) Through the mathematics model of induction motors, the working process of the motor can be simulated with Microsoft Visual C++ program. Discuss the relation...
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