| With the power electronics technology matures, the inverter is increasing in the application areas of human life. The study of the paper is a single-phase full-bridge diode clapmped three-level inverter which is beyond of multi-level inverter category.This paper briefly introduces the multi-level inverter development status and direction, describers three common multi-level topology: diode clamped three-level inverter, flying capacitor three-level inverter and the independent DC power cascaded five-level inverter. This paper focuses on the analysis of the single-phase full-bridge three-level inverter working principe and working mode, the stacked triangular carrier wave PWM control strategy is described in detail which is more suitable for the inverter topology in this article. In order to increase the stability and output characteristics of the whole inverter system, we use instantaneous output voltage of the outer and inner instantaneous inductor current,so the whole system is designed by dual-loop control system, the real-time tracking system is to measure the output voltage when it is changing, reducing the error between the output voltage and the given sinusoidal valtage. Due to DSP computing power and be able to meet the requirements of the instantaneous tracking, this paper also proposes improvements stacked triangular carrier PWM control strategy with the same phase based on DSP, driven by opto-isolation to achieve conversion DSP digital signal to an analog signal, get meet the PWM pulse signal to the main circuit. By MATLAB simulation software, the paper set up the same phase of stacked triangular carrier PWM and dual-loop control methods modeling and simulation, and analyzes the results in the case of load changes in the system where the output voltage and harmonic content changes, this paper also designed a prototype inverter system simulation and experimental validation of a single phase stability of this study full-bridge three-level inverter system. |
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