Research On Inertia Identification Algorithm Of Permanent Magnet Synchronous Motors

In order to improve the performance of AC servo systems,it is necessary to study the impact on the control system caused by the change of system parameters.Above all the external factors,the change of inertia parameter has the greatest impact on the performance of the system.When the system is in dynamic operation status,speed shock will be caused by the suddenly reduced inertia;In contrast,slower speed response and narrower bandwidth will caused by he suddenly increased inertia,so it is necessary to study the real-time identification on system inertia in the process of system operation.Parameter identification theory is combined with inertia identification of PMSM to identify the system inertia accurately,and feedback the value to system controller.Parameter self-tuning technology can be used to improve the interference immunity and robustness of control system.This thesis mainly focuses on the inertia identification of PMSM based on gradient algorithm,including the following parts:Firstly,the thesis briefly introduces the mathematical model of permanent magnet synchronous motor in dq coordinate system and its control strategy.Then takes a servo control system with speed loop as an example,analyses the influence on the dynamic performance of the system caused by the change of inertia,so it is important and necessary to study inertia identification technology.Then the principle and convergence of the gradient algorithm are analyzed in detail,the inertia identification models based on three different discretization methods are derived and then combined with gradient algorithm,so the inertia identification algorithm of PMSM based on gradient algorithm is obtained.In the Matlab/Simulink environment,the effectiveness and performance of the inertia identification algorithm are simulated and verified,in this process,several factors that affect the identification effect are analyzed in detail,and the identification results under different discretization methods are compared.Finally,the experimental platform is built to verify the inertia identification algorithm based on gradient algorithm.The relevant parameters in the algorithm and speed order of servo system can be sent to the DSP processor through upper computer interface based on Labview.The experiment results verify the correctness of the conclusion drawn in this thesis.