Research On Matrix Converter Fed Induction Motor Vector Control System

Matrix converter (MC) has extreme high power density, excellent characteristic of input and output, and the power flow is inherently bi-directional. It is quite suitable for naval ships, vehicle, aivation and astronaviation occasions which have strict requirements for volume, weight, input and output harmonic component. The matrix converter fed induction motor vector control system combines the advantages of matrix converter and vector control, which can realize high performance speed control.Firstly, the matrix converter control strategies, including the space vector modulation strategy and voltage-controlled two steps commutation strategy with intermediate intervals, are introduced in this paper. Then the mathematical model of induction motor is derived. Based on the model, this paper has analyzed the basic principle of rotor-flux oriented dual closed loop vector control system, and obtained the control block diagram of matix conveter fed indution motor vector control system.Secondly, with the no-load and short circuit experiments of indution motor, this paper has measured the accurate parameters of induction motor. Based on that, this paper has derived the mathematical model of induction motor vector control system and designed the controller parameters for current-loop, flux-loop and speed-loop regulators with the root locus and frequency response methods, in which the stator current-loop decoupling control strategies are mainly analyzed and compared. The paper also has established the induction motor vector control system simulation model in the Matlab/Simulink envirement, which confirmed that the feedback decoupling strategy is better than feedforward decoupling strategy, the effectiveness of vector control strategy and system performances.Thirdly, this paper has analyzed the rotor flux estimators of induction motor and designed the voltage-current hybrid model closed-loop rotor flux estimator, in which the sensitivity for rotor resistance variation and the ability to restrain DC bias signal of the rotor flux estimator are analyzed. Based on that, this paper has adopted the speed identification method basing on the induction motor state equations and mainly analyzed the selection of speed identification period in the digital implementations. Experiment results have validated the effectiveness of this method. Lastly, the experiment platform and software framework of indution motor vector control system are introduced. And a lot of experiments are conducted on the experiment platform, which validate the effectiveness of designed controllers and speed control performance of vectro control system.