Research On The Online Parameter Identification Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor is widely used in the industrial control because of its high efficiency, high torque to inertia ratio, small size and other advantages. In the control system of the high performance permanent magnet synchronous motor, the control performance of the system will be directly affected by the variation of motor parameters. In order to improve the operational efficiency of the motor, the motor control system should be provided with the function of parameter intelligent sensing. The permanent magnet synchronous motor is studied in this paper, based on the vector control, the load torque observation and the inertia identification are studied.First of all, the mathematical models of the permanent magnet synchronous motor in different coordinate systems are established. At the same time, the vector control theory is introduced in detail. Meanwhile, the block diagram for the control system of the permanent magnet synchronous motor speed and the current double closed loop is presented.Secondly, the observation principle of two methods which are state observer method and sliding mode observer method for the load torque observer are studied. The formula for the load torque observer of the permanent magnet synchronous motor is derived. And the state observer pole selection is improved. For the improved state observer, it is analysed by Lyapunov second method. The optimal control performance index is presented. Besides, the state feedback gain matrix is got under the optimal condition. The feasibility and correctness of two algorithms are verified by the simulation. The effects of observer parameters on the observation performance are studied as well.Thirdly, the identification principle of two kinds of online inertia identification methods which are model reference adaptive algorithm and gradient correction algorithm are introduced. The inertia identification formula for the PMSM is derived. Then, the effects of parameters on the identification performance are analysed. At the meantime, the fixed inertia and the variable inertia of the system are simulated. The correctness of two algorithms is verified as well.Finally, the hardware platform for the control system of the permanent magnet synchronous motor is set up based on the TI DSP chip TMS320F28069. Meanwhile, the software module of the load torque observer and the inertia identification are built. The identification algorithm is compiled and the hardware and software debugging of the system are completed. The feasibility and correctness of this project are verified by the experiment.