The Research Of Digital Control System For Single Phase Inverters

With the rapid development of the new power electronic devices and the digital signal processors, digital control inverters are widely used. Because it has significant advantages compared with the analog control: Simplify hardware circuits design, overcome the parameters of temperature drift in the analog circuits, flexibly control and easily realize the advanced control and so on. It makes power products designed not only reliable but also easy to make the mass production, and reduces the development cycle. Therefore, digital control power has become the trend of switching power product design from now on. The paper designs a digital control system of the single-phase inverter based on sine width modulate with Ti company TMS320LF2407A control chips and Power Module composed of the IGBT switches.In the first, the paper presents the current situation and development trends of the inverters. It puts forward the control of the soft switches circuit configuration and system design framework;analyses the principles of the sine width modulate and several major modulate methods, and through comparison illustrates the advantages and disadvantages of different forms of modulate. The article analyses the mathematical models of inverter and the principles of the PID digital control, then presents voltage current dual-loop PI control methods based on the speciality of the single phase inverter.In this third chapter, it mainly introduces the hardware system design, including the three main design modules: power supply modules, power drive modules and the DSP control modules. It describes the major device parameters of the system to identify and principles of the protection and detect circuits and design principles of circuit electromagnetic compatibility. It introduces specific achieved process of software system design in the last chapter, providing the system flow chart of main program and interrupt program, and also gives some illustration on software anti-interfere.During this paper, simulation model of the inverter system is established by the simulation environment of MATLAB/Simulink, which is used to validate the feasibility of the control scheme. Study of the system has carried out on theexperimental platform, and given the system test waveform. It is shown by the experimental results that the inverter power with digital control technologies designed by this dissertation can output steady voltage. It is consistent with the design goals.