Design Of The Photovoltaic Grid-connected Inverter Controller Based On DSP

PV power as the important means of solar energy is the most promising new energy technology.Photovoltaic industry is developing rapidly,but its cost and efficiency have a great negative impact on its development.An excellently worked photovoltaic grid-connected inverter controller not only can improve the operation efficiency of photovoltaic system,greatly reduce the system cost and push forward the development of new energy.Photovoltaic grid-connected inverter controller is with the hardware circuit and software algorithm,and only the most reasonable circuit design and efficient software algorithm can be combined to optimize the inverter system.Photovoltaic grid-connected inverter controller combined with the rapid development of semiconductor technology has diversified.Typical controller systems have four formations and different formations can improve the system performance and expand the scope of application system through cross combinations.At the same time the controller's main tasks have five aspects,and the way of implementing each one is over six.However,it is rather difficult to choose a highly stable system structure to design the controller hardware and achieve the high efficiency of the software algorithm.This paper is based on this point to do research on the photovoltaic grid-connected inverter controller software and hardware system,and designs a stably worked photovoltaic grid-connected inverter controller.This paper first studies the basic principles of photovoltaic grid-connected inverter and operation mechanism to make sure the control task of photovoltaic grid-connected inverter and to regard the characteristic requirements of the target as the basis to choose appropriate mode.Then,the paper will summarize and compare those field different schemes apply to by thoroughly analyzing the characteristics of the different schemes controller and their advantages and disadvantages.On the basis of concluding the typical controller system solutions,the paper will make up new schemes and their structure diagrams.Then the paper combines the system's functional needs,chooses the system components and designs the controller's hardware circuit and proves the correctness of the design through experiments.It is an important annulus that researching and implementing the core digital SPWM inverter system algorithm of technology photovoltaic grid-connected inverter controller.The paper derives the universal model of all kinds of digital SPWM algorithm through the analyses of digital SPWM sampling algorithm,and gives a novel universal model of digital SPWM sampling algorithm and its implementation method with digital controller technology,to verify the universal model,some experiments are completed using a 5 kW photovoltaic grid-connected inverter developed by our laboratory.On the basis of CCS and ISE the exploitation of the controller bottom drive can be realized.Finally the paper summarizes the main application and trend of the photovoltaic grid-connected inverter controller.