| Vector control technology that can control induction motor flux and torque separately through the coordinate transformation was proposed by German scientists in the seventies of the last century, and induction motor is equivalent to a DC motor model in this technology, which makes control of induction motors to obtain the rapid development. Now vector control technology has become the mainstream of modern AC variable speed system. AC variable speed technology has been applied in the various fields of national economy, and most of converter connected to induction motor are AC-DC-AC converter, this kind of converter generates a lot of harmonic pollution to grid and the energy can't flow bi-directional, these defects have a certain constraints to the development of AC variable speed.Indirect matrix converter has a good input and output characteristics, no large capacitor in the DC link and the adjustability of the input power factor and so on. Therefore, applied the indirect matrix converter to induction motor vector control system, not only can realize the advantages of vector control technology but also can reduce the harmonic pollution.In addition, as complexity of the mathematical model of induction motor and variability of induction motor's parameter during operation, in order to obtain high-performance induction motor inverter system, modern control methods need to enhance its robustness. In this paper, sliding mode method was selected in this indirect matrix converter induction motor vector control system.First of all, the working principle of an indirect matrix converter, control strategy, the commutation principle, the indirect matrix converter low-frequency transfer function and its simplified control strategy were described in the paper.Secondly, the paper introduced the mathematical model of induction motor, vector control technology in detail and coordinate transformation. In addition,it applied indirect matrix converter to vector control induction motor system.Then, the working principle of variable structure and the causes of buffeting were analyzed in detail. The parameters of sliding mode controller are derived in the mathematical model of induction motor.Finally, the accuracy of indirect matrix converter's control strategies and feasibility of application indirect matrix converter to induction motor vector control system and sliding mode control algorithm were verified by simulation, and has made good static and dynamic performance. |
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