Research On The Digital Control Technologies For Inverter Power Supply

This dissertation is focused on the research of the digital control technologies for the output voltage waveform of the inverter power supply. With more and more application of inverter power supply, the requirements for power quality get improved, therefore the waveform control technologies, especially the digital control technologies, become the hotspot on the research field of power technology. On the basis of the analysis to the mathematic model and work process of the sine inverter power supply, several digital control technologies for the single-phase full-bridge inverter and correlative control strategies are deeply studied.On the basis of circuit model of inverter power supply, the continuous and discrete space-state mathematic models are established, which provide theoretical basis for the design of control system. The inverter simulation model is established by the simulation software of MATLAB and SIMULINK, which is used to validate the feasibility of every control stratagy.On the basis of actual application on engineering and concrete requirements on power supply system, the experimental platform of 25Hz 110V inverter power supply based on the 80C196KC singlechip is designed. The designing thought of main and control circuit is presented to provide hardware basis for the implementation of every control strategy.Several control schemes such as Digital PID control, hybrid control and state feedback control are studied and simulation contrasts of different control strategy are presented.The repetitive control technology is deeply studied and a comprehensive theorietic analysis is carried out on the repetitive control system. System stability, steady state error and error convergence are discussed. A geographic explanation is presented for the stability condition. The mechanism how the repetitive control can eliminate the periodical distortion of the output voltage is set forth. A new method based on low-and-medium frequency cancellation and high frequency attenuation is proposed.In the end, the control software of system is compiled, the experimental research is carried out on the experimental platform and the experiemental waveforms under different loads are presented. It is shown by the experimental results that the inverter power supply with digital control technologies designed by this dissertation can output steady sine voltage.