The Research On Load Simulation System

The load simulation system has an important role in the research of servo control,especially in the load types which aren’t easy to be realized.The electric load simulation system has become the current research focus,with its advantages of energy feedback,fast dynamic response and high reliability.In this thesis,the load simulation algorithm of the load motor is studied and the simulation of a given load is established.Firstly,the dynamic model of load simulation system is established after analyzing the structure and working principle,and the character of the load simulation is analyzed in the form of transfer function.On the basis of these,the load simulation algorithms which include the direct torque control type and the direct speed control type are designed,and the limitation of the direct torque control type simulation range is pointed out as the discrete stability criterion of the direct torque control algorithm is analyzed.Then the load simulation algorithms are simulated by using MATLAB/Simulink,and the system’s feasibility is proved.Secondly,the hardware of the load simulation system is designed for the purpose of algorithm validation.Then the load simulation test platform with the core of the SIEMENS SINAMICS S120 inverter is developed,with the structure of drive motor and load motor energy feedback.Then the principle of the main modules and a variety of field bus protocol in the system are introduced.Base on these,the communication interface program,the drive control strategy,the algorithm realization and the human machine interface are designed.Finally,the experimental verification of the load simulation algorithms is carried out.After determining the response of the load motor in the velocity step,the sine tracking and any curve tracking,the effectiveness of the servo control with the load motor is determined.Then the identification about the moment of inertia and damping coefficient is completed.On the base of this,the experiments with the change of the load motor’s torque and the system’s moment of intertia show that the availability of the algorithm is verified.