Study On The Induction Motor Efficiency Optimization Based On Vector Control

In the modern society, the motor has been widely used in every industry,as themain power equipment, especially the induction motor’s electricity already accountsfor more than60%of industrial consumption. However, the efficiency of inductionmotors is very low in many cases, improving the efficiency of induction motor has animportant practical significance in the increasing demand for energy society.Firstly, the paper analyzes the loss of induction motor and builds the simulationmodel of induction motor considering iron loss. The paper adopts the rotor fluxoriented of SVPWM and Double-loop controlling to ensure the fast response andstability of the system and lay a good foundation for the efficinency optimizationresearch.Now there are three methods to achieve the efficiency optimization control: Lossmodel control(LMC), the stator current minimized control and the input powerminimized control. The LMC is sensitive to the changes of motor parameter whicheffects the optimization result. The stator current minimized control is only partlyoptimization. The input power minimized control can achieve the whole optimizationand cannot be effected by the parameters, so this paper adopts it.The paper makes a deeply research on the golden section and fuzzy searchcontrol, and then put forward a newly hybrid control method which gets the poweron-line and cannot be effected by the parameters.This method sets the reasonablescale factor and membership functions in the fuzzy control to change the research stepby the operating conditions, and then to suppress the torque ripple which caused bythe large step in the golden section. A dynamic current distribution method is putforward to improve the dynamic responses under the field weakening situation.Comparing the simulation results, the golden section has the certain convergencerate and using it in the later part can suppress the shock near optimal point to decreasethe convergence time. The newly hybrid search method combines the advantagesbetween the golden section and fuzzy search control. The newly method not onlyimproves the system efficiency,but also keep the system stable. Because ofunaffected by the motor parameters, the system has strong robustness. The simulationresults verifies the dynamic current distribution method’s effectiveness and thenewly hybrid comtrol method’s correctness, and then this paper makes an further research under the different operating conditions of the induction motor andanalysises the advantages of the hybrid control.