Study On Three Level Inverter SVPWM Control System Of The Induction Motor

The multi-level inverter is a circuit topology proposed in the early 1980s particularly applied in the high voltage variable frequency speed regulation area. It has the characters of reducing the switch stress and improving the quality of output waveform Together with the appearance of the excellent digital signal processor(DSP) makes the application of multi-level inverter come into being.At first, this thesis comprehensively describes the development future of power electronics techniques and the present development condition of multilevel inverter. The paper analyzes fundamental principle, and compares the advantages and disadvantages of three kinds of typical multilevel circuit. The paper analyzes the NPC invertor, compares three-level inverter with two-level inverter,concluting the advantage of three-level inverter.Secondly, this thesis systemeticly analyses the inherent property of three-level inner vetors,deduce the mathematical model for high frequence; presents the neutral point balance problem,which is the most important problem. Due to the neutral point balance problem,it presents two kinds of control algorithms to fulfill this system, detailedly introduces the concrete fulfillment process of each kind of algorithm and demonstrates the feasibility and validity of the corresponding algorithm with full and accurate data and diagrams; it presents relevant neutral-point-balance control scheme according to different algorithm and presents the concrete implement process, simulates the two kinds of algorithm and corresponding neutral-point-balance control scheme with MATLAB.Thirdly, this thesis analyses the cause of narrow pulse and present the algorithm to elimilate narrow pulse; simulates the algorithm with MATLAB.What is more, this thesis accomplishes all design and debugging of hardware circuit and chooses TMS320LF2812DSP as the main controller to complete system software.