Design And Realization Of Single Phase Inverter Power Supply Based On Digital Control

To overcome the inherent defects of analog control, bring the advantages of digital control into full play and comply with the development requirements of the inverter power supply with digital control, this paper proposes and implements a design of single phase inverter power supply based on DSP processor with digital control.In order to make inverter power output the standard sine wave, this paper chooses double frequency sine pulse width modulation (SPWM) technology by analyzing the fundamental structure and working principle of inverter power. For using the SPWM technology in digital processor, a detailed analysis of the symmetry uniform sampling SPWM waveform is given in this paper.In the purpose of designing control system of inverter, first, a single phase inverter model is created and a modified PID control algorithm is used. Then, both the schemes of single closed loop control and double closed loop control are analyzed theoretically. And they are modeled and simulated by using MATLAB program.Through analyzing the simulation waveform, this paper indicates that the dual closed loop control scheme is better than single loop control scheme in the stability and dynamics. Thus, the correctness and feasibility of the control scheme used in the system are verified from both the aspects of theory and simulation.According to the technical requirements of the power inverter, the specific design of the hardware circuits and software programs are given in the paper. The hardware includes power circuit based on full bridge inverter and control circuit based on DSP. The software of system adopts modular structure, besides the main program, it includes generation of SPWM control waveforms, A/D sampling, PID operation, frequency sampling and other subprograms.On the basis of research and design, a prototype of principle is produced, the debugging of the whole system is completed, and the test waveforms are shown. The results show that the prototype can get a stable voltage output, low harmonic distortion and the expected design objective is successfully obtained.