The Development Of Grid-Connected Photovoltaic Inverter

With the widely application of the solar photovoltaic system, grid-connected inverter devices of high quality are imminently needed in many fields. Based on making theoretic analysis of grid- connected photovoltaic inverter, a set of grid-connected photovoltaic sample inverter is developed based on singlechip of C8051F040. Following achievements are odtained: Based on the features of grid-connected inverter devices, a kind of control tactic that combines the multi-variable double-loop control with the synchronization phase-locked control is presented. The multi-variable double-loop control is used for current real time tracing to eliminate the principle error existing in the single-loop control. The synchronization phase-locked control guarantees the synchronization of output current of inverter with system voltage.The main circuit and hardware of controlling part of grid-connected inverter adopting singlechip of C8051F040 as control core are designed and the anti-jamming of hardware and software are also designed. The parameters of main circuit, driving circuit, protecting circuit and filtering circuit are given in this thesis.Based on the control functions of the device, the software of controlling part is designed. The data transmission between the grid-connected inverter and the up-computer is also realized by using Delphi, whereby, the friendly interface is built, which makes remote management and supervision of the grid-connected inverter be convenient.The results of experiments and tests indicate the grid-connected inverter system is characterized by output of good wave and high operational reliability and can be industrially utilized after further improvement is made.