Research On Three-phase Three-level Inverter System By Model-based Design

Multi-level inverter system is more widely used because of some advantages,such as low harmonic content, small switching loss and so on. However, themulti-level inverter system includes more switching elements. If control usetraditional analog devices, the circuit is too large. If control use embedded chip, theprogram code is too complicated. This paper introduces the Model-based Design inthe research, a three-phase three-level inverter system with closed-loop control andsuperior performance is completed by this new type of embedded systemdevelopment pattern. On the one hand, the new method of power electronics researchis explored, on the other hand the superiority of embedded system development byModel-based Design is proved.After the main circuit and control strategy of a three-phase three-level invertersystem are determined, the method of Model-based Design is studied deeply.MATLAB is used as the designed software. The mathematical principle of carrierinverse disposition PWM is analyzed, and the mathematical model for the controlpart is set up in Simulink. The model is deployed and modified for target chipthrough a series of verification and testing means which is provided by MATLAB.The automatically generated code is compiled into chip to implements the open loopcontrol of a three-phase three-level inverter system. And then the design is perfect,the model is modified, the hardware circuit is upgraded. The closed-loop system withfrequency conversion variable pressure and adjustable midpoint potential iscompleted. The experiment result shows three-phase three-level inverter system canrealize the change of the voltage and frequency through the operation of externalbutton, also can stabilize the output under the condition of existing disturbance andeffectively restrain the drift of midpoint potential.This dissertation proves that the Model-based Design with high quality, high efficiency and economy. This new type of embedded system development pattern isintroduced in power electronics subject. In the future Model-based Design can bemore widely used in the other direction, improve the design quality and efficiency.