Research On Single - Phase Inverter Based On DSP Control

Science and technology change rapidly today, power electronics technology is also in constant innovation, with high performance and low cost digital processor is published, the traditional analog circuit transforms gradually to the digital circuit. In the inverter power supply field, conventional analog controller has exposed its inherent defect, and the digital controller not only can make up its deficiencies and easier to realize the advanced control technology. Therefore, the inverter power supply has become the development trend of current inverter field. As the market demand for400Hz medium frequency power supply in the military and civil field increasing, therefore,400Hz medium frequency inverter power supply of high quality, high performance has become a hot spot of research in the field of power. In this paper, a high performance digital signal processor TMS320F28335as the main controller, and based on the research and Realization of single-phase400Hz inverter.Firstly, this paper discusses the working principle of single phase inverter, the modulation mode selection the SPWM modulation of unipolar, bipolar and unipolar frequency are compared and analyzed, finally chose the modulation of frequency SPWM monopole. Through the comparative analysis of the sampling method of the symmetry principle and the asymmetric regular sampling method, and the two method of SPWM pulse width for the quantitative calculation, considering the asymmetric rules to realize digital sampling method of SPWM. In unipolar switching frequency modulation system based on the original can be doubled, the ripple voltage frequency inverter output doubled, to reduce the volume of the output filter, improve the performance of the filter, but also reduces the harmonic content, improving the output power quality. Asymmetric rules by the method can not only make the system sampling frequency doubled, improves the precision of control system and can eliminate the even harmonics, improve the quality of the output waveform is very good.Then, this paper uses the voltage, current instantaneous value feedback combined with digital PID inverter digital control technology, and mathematical modeling of relevant, given the relevant transfer function and its analysis. Digital implementation of PID on the integral separation improvements make it accord with the actual demand of this system, and deduces the method of digital PID parameters tuning. Through the analysis of the control technology that can be drawn:voltage, current double closed loop feedback PID control technology can improve the dynamic characteristic of inverter power supply system, reduce the steady-state error, improve the quality of the output waveform.At last, this paper completes the hardware design of the400Hz inverter system according to the plan, and the important parameters related to the hardware design of the calculated theoretically, and constantly in the experiment fine adjustment and calibration. At the same time also completed the software design of the whole system, the software implementation of SPWM are discussed in detail. Through analyzing.the experiment waveforms and data, show that the system design is reasonable and reliable, and the quality of the output waveform is improved.