Design Of Three-loops Control For Digital Inverter Based On DSP

With the rapid development of the new power electronic devices and the digital signal processors,igital control inverters are widely used.Because it has significant advantages compared with the analog control:Simplify hardware circuits design,over-come 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 pro-duct design from now on.This paper detailedly analyses the process of designing a digital control system of the single-phase inverter based on sine width modulate with Ti company TMS320F2812control chips and Power Module composed of the IGBT switches.Firstly, the paper presents the current situation and development trends of the inverters.It puts forward the control of the circuit configuration and system design framework; analyses the principles of the sine width modulate and several major modulate methods.The article analyses the mathematical models of inverter and the principles of the PID digital control.then presents a new PI control method named Three-loops Control which uses the inductance current inner loop, the capacitance capacitor voltage middle loop, the voltage effective value outer loop.In the fourth chapter, it mainly introduce the hardware design of the system. Including the design of the five main modules:the A/D sampling module, power module, the protection circuit module, power supply module and DSP control module. Several key pin functions in the main module are introduced, including the high and low conversion pin and soft-start pin.In the fifth chapter, it mainly introduces the specific process of software design and implementation of the system, and highlights the monopole harmonic software design principles and implementation steps. The final chapter, establishes a simulation model of the inverter system to verify the feasibility and effectiveness of the control program using MATLAB/SIMULINK simulation environment.