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Research On Speed Sensorless Induction Motor In Vector Control Based On Mras

Posted on:2019-11-09Degree:MasterType:Thesis
Country:ChinaCandidate:L L WangFull Text:PDF
GTID:2382330566488992Subject:Control theory and control engineering
Abstract/Summary:PDF Full Text Request
The process of industrial modernization has developed rapidly,many mechanical automation equipment are gradually liberating mankind from heavy physical labor,as an efficient and reliable dragging device,asynchronous motor occupies an extremely important position in the automatic control system.As people's requirements for the accuracy,quality and cost of industrial products continue to increase,the asynchronous motor speed control systems are constantly being improved by researchers.Asynchronous motor vector control as the control idea with relatively mature theory and high motor control precision,has been extended to industrial production,and further improvement based on this control system has gradually attracted the attention of many scholars.Using speed identification algorithm instead of speed measurement device in asynchronous motor can not only reduce costs,but also improve system stability and reduce system maintenance difficulty.Therefore,it has important theoretical significance and application value for the research of speed sensorless vector control.First of all,based on the idea of vector control,the dynamic mathematical model of asynchronous motors is constructed,the system simulation of vector control of asynchronous motors is established,the advantages and disadvantages of several common regulators in the application of asynchronous motor vector control simulation are analyzed.Then,the model reference adaptive control algorithm is studied and its stability is analyzed.By comparing and analyzing the error signals based on flux linkage and model reference adaptive power based on reactive power,it is found that a large number of higher harmonics and noises contained in the input signal seriously affect the accuracy of the reactive power model reference adaptive speed identification algorithm.In order to overcome this problem,a third-order Butterworth low-pass filter was designed to simultaneously filter the voltage and current signals,and an improved model reference adaptive asynchronous motor speed identification method based on reactive power was proposed.Finally,considering the traditional speed PI regulator is seriously affected by changes in the motor parameters,the advantages and disadvantages of the single speed neuron PI controller and the traditional PI controller are analyzed.After a comparative analysis,an improved single neuron PI regulator was designed and applied to the improved speed sensorless vector control system.The introduction of the filter overcomes the problem that the reactive power model reference adaptive algorithm has a large input signal fluctuation and contains a large amount of noise to degrade the dynamic performance of the system.The simulation results show that the improved reactive power model reference adaptive system reduces the amplitude and frequency of the reactive power signal output by the reference model,and the improved steady-state and dynamic performance of the system as well as the speed prediction accuracy are significantly improved.Adding an improved single neuron PI regulator improves the dynamic characteristics of the speed of the induction motor vectorless speed control system.
Keywords/Search Tags:Asynchronous motor, Vector Control, Speed Sensorless, Model Reference Adaptive, Single Neuron PID controller
PDF Full Text Request
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