The Study Of Vector Control Of Induction Motor And Flux Observer

With the progress of science and technology, the research of the contro lstrategy gradually thorough, induction motor variable frequency speedregulation system in the industrial fields has been widely used, at the same timecontrol of the asynchronous motor performance put forward higher requirements.In this paper, on the basis of the induction motor vector control, the structure ofseveral common flux observations, the sensitivity to the parameters in the fuxobservation and the application of Active Disturbance Rejection Control in theasynchronous motor has been studied. In the same time the matlab simulationresults validate the theoretical analysis result.First of all, based on the coordinate transformation, We can get themathematical model of asynchronous motor. Present the basis of researchcontent: the rotor flux oriented vector control system. Based on the rotor fluxoriented vector control, through the simulation analysis, two different currentclosed-loop control methods has been studied: hysteresis control and SVPWMcontrol. By comparing the different results of the asynchronous motor under twokinds of control mode, get the basis current closed loop control mode: SVPWMcontrol.Then, based on the research on rotor flux orientation, the accuracy of therotor flux’s amplitude and phase is important for control system forasynchronous motor. So this paper studies the basic structure of the four kindsof flux observer. But in the process of the operation of the asynchronous motor,weak magnetic, temperature, skin effect and so on lead to the change of themotor parameters, these changes will influence the outcome of flux observation,and then affect the accuracy of motor control. We study the observed value andthe actual value ratios, ratio analysis of frequency response function. Underdifferent parameters change, get the specific impact of different flux observer,The final analysis, the open loop model receive a greater influence on theresistance inductance, closed-loop model receive the influence of parametervariation is small.Finally, in the process of the motor running, there are a lot of uncertainfactors, based on the complex structure characteristics of asynchronous motorand PI regulator will produce the problem such as the limited robustness.According to the control characteristics of the asynchronous m otor, discussusing ADRC in induction motor speed control system in specific ways. On this basis, through the matlab simulation, mainly through the study of no-load start,increase the load, motor parameters ande speed change, and in the sameconditions, research the comparison between the simulation results of the PIregulator research and the ADRC control. Based on ADRC control system hasbetter robustness and disturbance resistance.