Research Of Parameter Identification On Induction Motor Vector Control System

With the emergence of new control strategies of motor and high performance microcontrollers,AC induction motor has been widely used in many fields due to its significant structural and performance advantages.Vector control technology has the advantages of high control precision and fast dynamic response.But the method is highly dependent on the dynamic model of the motor,so the accuracy of the motor parameters estimation has higher requirements.In this paper,the parameter identification of induction motor based on vector control technology is studied,and an induction motor parameter identification system is developed.Firstly,the principle of SVPWM and its key problem are introduced.Based on the coordinate transformation and motor mathematical model,the principle of vector control used the rotor magnetic field orientation is expounded,and its digital realization process is analyzed in detail.Next,the hardware platform design of the motor vector control and parameter identification system based on Freescale DSC MC56F84789 as the core controller is discussed.In particular,the circuit design of DSP core control board and the auxiliary switching power supply & IGBT driver board are made a detailed description.The structure of the system power main circuit module is briefly described.Then,the parameter identification methods of the induction motor are studied deeply.The traditional motor parameters test method of no-load and stall is described.And the following parameter identification methods are evaluated by values obtained in this method.Analysis of the induction motor off-line parameter identification strategy,based on the static model of the motor,the paper makes full use of the resources of the hardware platform to carry out the DC test,single-phase test and no-load test and according to the actual conditions to simplify the identification process.The off-line motor parameters identification method has the characteristics of simple,and it is the base of on-line parameter identification methods,so it also has an important research and application value.The on-line motor parameters identification method based on recursive least-square is discussed.At last,the software design of the system,including the motor vector control algorithm and the induction motor parameter identification algorithm,is carried out using CodeWarrior and Processor Expert built-in it.The experiment of parameter identification was carried out on an 11 kW induction motor in the laboratory,and obtained the motor parameters with high accuracy.It is verified that the reliability of the system hardware and the rationality of the software design are fine.