Research On A Novel Method Based On Stator Flux Orientation Decoupling Control

Dynamic mathematical model of induction motor have nonlinear, multivariable, strongcoupling, higher order, and other characteristics. The schemes for motor control have many,but the most common application has two kinds, Vector control and direct torque control. TheVector control system, which is driven by the current output control inverter and based onrotor flux oriented, is most widely used, but the sensitive to the rotor parameters limits theimprovement of dynamic performance at low speed; And the Direct torque control does notdepend on the motor’s dynamic mathematical model and parameters, but the biggestdrawback is the high torque ripple so that it is not suitable for the use in low speed range.In this paper, the research background and significance of the AC speed regulationsystem are briefly introduced at first. Aiming at voltage output control converter, this paperanalyzes the decoupling control equation theoretically, respectively according to threemagnetic chain orientations of the rotor, stator and air gap. And all can achieve completedecoupling control after adding some form of decoupling control item. Nowadays, because ofthe rapidly improved capacity of the embedded microprocessor computing, the calculation ofthe decoupling is not a problem; Theoretical derivation indicates that flux linkage and torquedetection algorithm according to the air gap and stator flux orientation has nothing to do withthe rotor parameters, can greatly improve the closed loop control system’s robustness andaccuracy. Shows that the proposed scheme has more advantages in application.The models inthe MATLAB/Simulink prove them right.In this paper, the stator flux oriented solution is selected for experimental research.Variable frequency speed control system based on the voltage type inverter is designed.Aiming at the question that the cross coupled closed loop system exists in the stator fluxdetection link, this paper analyses the coupling system’s discrete model and the recursivealgorithm’s achievement. The design contains respectively the main circuit, control circuit,driving circuit and over-current protection circuit. And the experimental verification indicatesthe correctness of the circuit design.Finally, based on the TI Company’s DSP development board TMS320F2812, each partof the experimental platform is digital realized in CCS programming environment, and showsthe initiatory experiment results.