Improvement Of Controller Performance Of The Electric Load Simulation System With Three Loops

The electric dynamic load simulator has been widely used in the semi-physical ground simulation of aircraft.Due to the existence of the surplus torque,it should be the first problem to solve in the control.Besides,the loading accuracy and loading bandwidth of the system also need guaranteed.In order to meet the above requirements,the loading system of the electric load simulator usually adopts three closed loop control structures,but the performance of the ordinary three closed loop control structure is relatively simple,and the robustness and disturbance resistance of the system are not considered.Therefore,this paper aims at improving the robustness,disturbance resistance and dynamic stability of the electric load simulator,starting with the design of each link controller,and carries out theoretical analysis,simulation and experimental research.First,the paper studies the control structure of the loading system of the electric load simulator,and compares the influence of the single closed loop control structure,the double closed loop control structure and the three closed loop control structure to the performance of the system.In order to enhance the stability of the system and make the control structure meet the performance requirements of the electric load simulator system,the current-speed-load torque three closed loop control structure is used to control the loading system.In order to improve the dynamic performance and robustness of the inner current loop of the load system of the electric load simulator,the performance improvement strategy of the inner loop controller is studied.When the system works dynamically,the parameters of the loading motor will change to a certain extent.The traditional cross decoupling PI current control method can not meet the dynamic working condition of the system because of the inductance parameters in its controller parameters.Therefore,the complex vector current control method with no inductance in the controller parameters is studied.The robustness and dynamic performance of the two are analyzed.In order to improve the dynamic stability,robustness and disturbance resistance of the speed loop of electric load simulator,the speed loop controller of electric load simulator is studied.The auto disturbance rejection control method is used to design the speed controller,and the speed given differential is added to the state error feedback control law as the improvement of the traditional auto disturbance rejection control.The stability and robustness of the speed controller are analyzed.Due to the existence of the surplus torque problem of the electric load simulator,its load torque controller is required to restrain it.Therefore,this paper uses the proportional resonance control method to design the load torque controller,and uses the root locus method to set the controller parameters for single frequency sinusoidal signal.Finally,with the simulation experiment of the previous paper,the overall loading performance of the three closed loop control structure is verified experimentally.The experimental results prove that the improved controller design method in this paper can improve the robustness,immunity and dynamic stability of the system.