Research On Digital Control Technology Of Inverter Power Supply Based On DSP

With the rapid development of microprocessor,digital control has been widely used in various control situations.For inverter power supply,the application of digital control technology has become the mainstream of its development direction.Digital inverter power supply is not only simple control circuit structure and debugging is convenient,but also has the advantages of high efficiency and low cost.The most prominent advantage of digital inverter power supply is that it can use advanced control algorithms and has high portability of software.In this paper,single phase full bridge inverter circuit based on DSP-F2812 control is selected as the research object to analyze the system output characteristics under different control strategies.In this paper,by analyzing the working principle of single phase full bridge inverters,the corresponding mathematical models are obtained,and the mathematical models in continuous domain and discrete domain are compared and analyzed.The open loop control system has poor performance and is vulnerable to load changes.To solve this problem,a closed loop control is proposed.Although single closed loop control can overcome some disturbance of load variation,its dynamic characteristics are still not ideal.In order to overcome this problem,double closed loop feedback control strategy is adopted.In this paper,the voltage RMS outer loop instantaneous value inner loop control and voltage outer loop inductor current inner loop control are designed respectively,and the system performance parameters under different strategies are compared.According to the simulation results of the inverter system under various control strategies,the rationality and feasibility of the control method designed in this paper are proved.In view of the difficulty in setting the control parameters of traditional PI control and the high precision of the mathematical model of the controlled system,this paper chooses fuzzy PI control to overcome the above problems.According to the design rules and principles of fuzzy control,it is combined with PI control to give the design process of fuzzy PI control.In order to verify the effectiveness of the control method,the simulation experiment was carried out on MATLAB.The simulation results show that the fuzzy PI control is not easy to produce overshoot,and it can effectively overcome the voltage abrupt caused by load fluctuation.For the inherent sampling delay problem of digitization,this paper chooses a one beat delay control solution.The influence of digital zero order holder and lag beat control on the stability of inverter power system is studied,and the correctness of the related theory is verified by simulation experiments.Finally,a digital inverter power supply experimental platform based on DSP-F2812 was built and related experimental research was done.The experimental results prove that the design of the inverter power system is feasible.