Research On Vector Control Of PMSM Based On Sensorless Observer

Permanent magnet synchronous motor(PMSM) has a simple structure, low cost,manufacturing process streamlined, lower probability of failure strength, so that in the area of industry, will broad development prospects. However, due to the dependence on the sensor of the rotor position and the motor speed, and the control system with the sensor is difficult to avoid the motor during operation, the internal temperature rises and hardware consuming inconvenience. Therefore, under the conditions of using sensorless vector control of PMSM control strategy is the main study content in this paper.Firstly, this article chooses under the condition of the sensorless vector control of PMSM based on the sliding mode observer designing of vector control, by estimating the rotor position and speed so as to omit the hardware sensors. Sliding mode variable structure existing in the "chattering" still exists in the sliding mode observer, in view of this problem suggests the switching function of the hyperbolic tangent function replaces the original form improved, and normalizing the phase-lock loop, so that it will improve the estimation accuracy of the system. The simulation results show that the improved sliding mode observer has the good dynamic performance, and it is more suitable for the high speed environment.Moreover, motor speed loop typically uses a conventional PI control in vector control but PI control has certain draw back, so based on extended state observer method is proposed.Extended state observer is the core part of ADRC, the ADRC is used instead of the original PI control. Based on ADRC with PI control simulation proves that ADRC has faster response and stronger control effect of anti-interference ability.Finally, ADRC process has such a defect like more parameters. Linearization of the ADRC, at the same time in order to obtain better accuracy, so adds an improved fal function before the control object. Further by calculating the time scale of PMSM, you can through the corresponding functional relation calculate the parameters of ADRC. For different internal parameters of PMSM, ADRC parameters can be directly calculated. The simulation results can be seen through parameter variables become less and still maintain the original ADRC control accuracy and response rates and strong anti-interference ability.