A Research Of Photovoltaic Inverter Based On MCU' Control

The energy of sun is a huge self-born resource, is one of the main substitute of petrifaction resource largely used at present , is one of cleanly resource available by human. Therefore, the exploiture of the energy of sun has a great strategic meaning. This thesis has designed a unattached photovoltaic inverter. The inverter is low cost, high-efficiency, has a simple structure,digital control and display. The output voltage has a high quality and the speed of dynamic response is quickly.The whole system includes two parts, one is direct current charge system of solar battery, another is inversion system. In the charger research part, this thesis has introduce the deferent characteristic of solar battery and the charge characteristic of storage cell in detail, and works out a double phase unvarying voltage strategy for charging up depends on the characteristics of solar battery and storage cell. The strategy not only realizes the maximum power output of solar battery, but also electricizes storage cell correctly. The main circuit is constructed by the circuit topology of Boost Chopper to achieve the design of charge control for storage cell.In the inversion part, the thesis summarizes usual circuit structure and compares each advantages and disadvantages, choose the design policy of "full-bridge converter+ high frequency increase voltage+ LC filtering", this design constructs the circuit easily, makes the cost lower and make the system easy to control. And then, this thesis introduces the principle and expressions of the main circuit and its parameters choice, and makes sure the simulant machine's parameters used in experiment.The control system uses double core of AVR microprocessor named ATmega16L to control the inverter, the two MCU make up of master/slave model. The inverter uses single polarity SPWM to modulate the sine wave signal, devises double closed loops of voltage and current feedback to control the output voltage steadily. The thesis introduces the principle and configuration of double closed loops of voltage and current feedback detailedly, and sets up the continuous mathematics former and the discrete mathematics former of full bridge converter's status space, also uses the MATLAB/Sim-...