Wound Rotor Induction Motor Of Variable Frequency Speed Regulation And The Research Of Optimal Energy Efficiency Control Strategy

With the state and society paying more and more attention to the environmental protection and energy saving,it also put forward a new requirement for motor energy saving,and demands higher speed control performance.The induction motor which is widely used in the actual industrial production,taking its place steadily with the circumstance of the fast developing of permanent magnet synchronous motor and all kinds of new motor,because of its simple structure,reliable operation,convenient maintenance,as well as its low price.At present,the higher starting performance requirement places are still use the induction motor with wound rotor,such as wind motor and ball mill.The common problem they have to face is the backward control technology and equipment aging.To solve these problems,this paper put forward the optimal control strategy of comprehensive energy efficiency based on the variable frequency speed regulation system of wound rotor induction motor.The purpose of these behavior is putting energy conservation reform of old equipment into effect.Firstly,this paper has recomputed the parameters of the sample motor by off-line parameter identification.The energy saving control method is divided into two parts: starting and steady-state operation.In the starting method,this paper has taken method of the rotor with series resistance into consideration and also calculated and simulated the optimal starting resistance.This paper has summarized the shortcomings of the series resistance starting mode and proposed the non-impact starting mode of the rotor side of motor and verified its accuracy by software simulation and experiment.Secondly,on the operation of energy saving control,this paper is divided into two parts: rotor side and stator side energy saving.On the choice of the ways of energy saving in the rotor side,this paper sum up the pros and cons of non-impact starting mode of the rotor side,proposed an economical speed control mode based on the rotor side variable frequency speed regulation,analyzed its basic principle and technology of the switching operation,carried on the simulation analysis and designed the whole hardware circuit of speed control system.This paper analyzed the basic principle,the dynamic process and capacity rule of cascade control system in detail.This paper carried on parameter calculation and system structure design of voltage type PWM rectifier with chopper cascade control system,and analyzed it through the simulation.The optimal energy efficiency control strategy based on the rotor side variable frequency speed regulation is proposed by comparing the energy saving degree of the cascade control and the rotor side variable frequency speed regulation.Finally,on the choice of the ways of energy saving in the rotor side,compared with the traditional stator side variable frequency speed regulation,this paper proposed the best way to flux control,obtained its energy saving range by simulation analysis,and proposed the optimal voltage control based on the above.After the simulation analysis of this method,the optimal energy efficiency control strategy of stator side based on load partition is proposed by comparing the energy saving interval of the optimal flux control and the optimal voltage control.