Research On Photovoltaic Grid-connected Inverter System Based On Dual-axis Tracking

With the continuous development of economy and society, the global demand for electricity presents index increase in recent years. As a result it brings catastrophic problems such as energy shortage and environmental pollution. The basic way to solve the problem is to develop new energy sources to replace traditional energy.At present, the solar energy is more and more brought to the attention of countries all over the world. These years China becomes the world’s largest solar photovoltaic products manufacturing base. Although solar cell production accounted for the largest share in the world, but related to photovoltaic battery application of downstream products did not obtain corresponding development, This article will focus on optimizing the photovoltaic grid-connected system architecture design, from all aspects of electricity yield to the grid for solar cells to conduct a comprehensive optimization, so as to improve energy efficiency.In this paper, the design of the whole working process of the system is that the solar trajectory tracking sensor detects the sun position in real time, then output the analog signal after processing into the controller. The signal will be converted into digital quantity, control and drive stepper motor motion, making photovoltaic receiving panels remain perpendicular to the incoming light, in order to make PV cells" light receiving area getting the maximum utilization rate. At the same time, the PV array output direct current into the grid inverter, grid inverter converts de to alternating current conform to grid requirements. The output is single-phase220V alternating current and frequency50Hz. In order to realize the sine wave output, inverter adopts PWM control. Inverter output after EMI filter is connected to a power grid. The whole circuit control unit adopts dsPIC33F series MCU. Power grid voltage and current are sampled by sensors, and then controlled by the microcontroller through the PLL to keep the inverter output current synchronized with power grid, and also used for detection of an island.