Research On Current Loop Deviation Decoupling Control Strategy Of Fermanent Magnet Synchronous Motor

Permanent Magnet Synchronous Motor has been widely used in electrical transmission,aerospace and other fields due to its superior speed regulation performance.PMSM has the characteristics of nonlinearity and strong coupling.The control system,with PMSM as the controlled object is a system which is of strong coupling.In high performance AC drive control system,high precision current loop control is an important part of the system.The decoupling control of the current ring can improve the control accuracy of the system.Therefore,in order to realize the high precision control system,the current loop must be decoupled and controlled.fFor the current feedback decoupling control strategy and the deviation decoupling control strategy,the two control strateg:ies can realize the complete decoupling control of the current loop when the parameters are matched,while,it cannot be realized when the parameters do not match.In order to solve this problem,based on the theory of compensation control,the disturbance observer is introduced on the basis of the deviation decoupling control strategy.The voltage deviation caused by parameter changes,mutation load and dq axis current coupling is regarded as the external disturbarce of the system,and the disturbance observer is used to observe the external disturbance.And feed it back to the voltage input for compensation.The decoupling characteristics of the system parameters are quantitatively analyzed by observing the amplitude frequency characteristics of the transfer functions of current feedback decodpling control,deviation decoupling control and the introduction of disturbance observer.In order to prove the feasibility and effectiveness of the deviation decoupling cootrol of the disturbance observer,the samulation verification is carried out in Matlab/simulink,and the experimental verification is carried out on the twe-level inverter experimental platform TMS320F28335,which Is the core digital signal processor.The experimental results show that:1.When the motor nameplate parameters are matched with the actual parameters of the motor,the current feedback decoupling control,the deviation decoupling control and the devia-tion decoupling three control of the disturbance observer can realize the complete decoupling control of the current loop2.When the motor nameplate parameters and the actual parameters of the motor do not match,the current feedback decoupling control strategy and the deviation decoupling control strategy cannot realize the complete decoupling control of the current loop.Compared with the current feedback decoupling control and the deviation decoupling control,the deviation de-coupling control strategy with disturbance observer can better realize the current decoupling control and improve the robustness and decoupling effect of the system.