Pmsm Speed Regulation System Based On Active Disturbance Rejection Control

In recent years, with the property improving and the price falling, the permanent magnet synchronous motor(PMSM) has gradually replaced the asynchronous induction motor as the core of AC speed regulation system. As the representative of high performance speed regulation system, the PMSM is given a high expectation, but the load disturbance has become the biggest obstacle to its further development and promotion. In order to counteract and suppress the bad influence on motor speed, the Active Disturbance Rejection Controller(ADRC) technology is researched and a compensated ADRC based on Sliding Mode Control(SMC) has been proposed.Firstly the paper analyzes the principle and structure of ADRC technology, and a standard ADRC for PMSM speed regulation system is built. However this controller is not perfect, the load disturbance will affect the accuracy of the extended state observer(ESO) and cause the degradation of system performance. To solve this problem, the paper proposes a compensated ADRC which can achieve a partial compensation for disturbance through identifying the moment of inertia and observing the load torque. Meanwhile, in order to simplify the structure of controller parameters and make the tuning process rule-based, the SMC is introduced to replace the non-linear function. It solves the problem successfully that the parameters in standard ADRC is difficult to adjust.To obtain the moment of inertia, the thesis presents an identification method based on integral. Using the nature of integral operation and combining the specific speed signal, the identification expression without other unrelated variables can be extracted from the motor equation. In order to expand the scope of the method and not to affect the normal operation of the system, an identification algorithm based on Landau discrete recursive is proposed. It can identify the moment of inertia accurately by selecting the appropriate adaptive gain.To realize the observation of the load torque, the estimation method based on state reconstruction is researched. On the basis of full-order observer, the paper proposes a reduced-order load torque observer. By analyzing the pole placement and its stability, the observer can achieve an accurate observation of the load torque.Finally, not only the simulations of proposed algorithm are implemented, but also the platform of PMSM speed regulation system based on DSP is built, and the experiments on it prove the effectiveness and feasibility of the algorithm well.