Research On Efficiency Optimization Control For Induction Motor In Full Speed Range

Due to the advantages of simple structure,low cost and high reliability,induction motor is widely used in all walks of life,which electricity consumption accounted for about more than 60% of the total industry power consumption.In practice,most of the induction motor is in light load condition,which often result in the low operating efficiency,and the serious electric energy waste.So,for environmental protection and energy saving value today,improving the efficiency of the induction motor light load has important practical significance.This paper aims at induction motor in full speed range,and researches on light load operation condition to deal with efficiency optimization.The main contents include below.Firstly,a loss mode of induction motor based on full speed is established,which accuracy affects the efficiency of optimization effect.According to the operation of induction motor in full speed range and the analysis of characteristics of loss and efficiency,a time-varying coefficient loss model considering the influence of the leakage inductance is established,which is more in line with the actual working conditions.According to the established loss model,and adopt the method of vector control to derive the controllable loss mechanism relationship affected by rotation speed and the current,in the synchronous rotating coordinate system.Secondly,the idea of efficiency optimization control is proposed for the induction motor running in full speed range.By considering the limitation of the capacity of the inverter,DC bus voltage and induction motor rated current in full speed range of induction motor,the regional division of full speed range is carried out.To research on the optimal energy saving condition of the induction motor in each region based on the optimization theory.Thirdly,the change of static parameters adversely affects the loss model when induction motor is running.A new method of identified offline about parameters of induction motor to prevent the loss of motor nameplate parameters and the change of motor parameters in the long run is proposed.In response to the problem of the slow dynamic response and the maximum output torque of non-constant torque,the principle of dynamic current distribution is proposed.Fourthly,a simulation experiment is carried out for the efficiency optimization control strategy proposed by induction motor in light load operation.By changing the load rate of different operating regions of induction motor to test the effect of energy saving.Dynamic response capability is abruptly tested by adding load.