DSP-controlled Inverter Power Supply Design And Dead Zone Optimization Research

With the developments of science and technology,the application of inverter power is more extensive.At the same time,the requirements of the inverter power is also getting higher and higher,prompting the inverter power continuously toward the high-frequency,digital,high-performance direction.Because of the power switching devices in inverter power switches are not ideal,in order to prevent the same bridge arm of the switch tube through the phenomenon,causing damage to the device,need to set certain dead time in its driving signal.Dead time is usually relatively short,but now the frequency of power device switching device is continuou improvement,The dead-zone has a more serious effect on the output voltage of the inverter.The dead time effect aroused the attention of scholars,and compensation of dead has become an important subject to improve the output waveform of inverter.In this thesis,the mathematical model of inverter is first built.Based on this model,the double Fourier analysis is used to draw the conclusion that dead time effect can cause the output voltage fundamental wave loss,phase shift,low harmonic generation and output current clamping.Secondly,according to the adverse effects of the dead time effect brought by the comparative analysis on the basis of traditional compensation method,a dead-zone compensation strategy based on repeated control is adopted,the dead-zone effect as a disturbance cycle in nature,and the use of repetitive control technology to eliminate the disturbance.The MATLAB simulation shows that the repetitive control technology can effectively compensate for the loss of the fundamental wave,reduce the low harmonic and improve the quality of the power supply.Finally,a power supply prototype with a power of 480W output of 220V/50HZ is designed.The prototype mainly includes the Front push-pull DC-DC,Back stage inverter circuit of DC-AC,and the sampling and protecting circuit.Among them,the control chip adopts the TMS320F2812 series DSP of TI company,the setting of dead zone and the repetitive control algorithm are all realized in the DSP chip.The experimental results show that after adding dead-time compensation method based on repetitive control,the harmonic content is greatly reduced,and the component of the fundamental wave is added,and the power efficiency is significantly improved..