Design Of Single Phase Photovoltaic Grid Connected System Based On Internet Of Things

Energy is the blood line that dominates the world economy,and it is also the basis of human activities.Ensuring the supply of energy actually guarantees the sust ainable development of mankind.However,with the rapid development of the scientific and technological revolution and the industrial revolution,mankind is facing not only the high consumption of fossil energy sources such as oil,natural gas and coal,but also the need to manage the increasingly severe environmental pollution caused by excessive development.Solar energy is one of the clean energy with the most development potential.Its advantages of environmental protection,high efficiency and renewable energy are more and more popular i n countries all over the world.There are various forms of solar energy development,such as centralized photovoltaic power stations,"fish-light complementary" power stations,forest-light complementary power stations,and distributed photovoltaic power stations,all playing important roles in different economic fields,and in the past two decades,the new installed capacity in the world has also been increasing,and the total installed cap acity has reached a new height.However,as more and more photovoltaic power plants are put into use,especially in distributed photovoltaic power plants in various regions of China,due to the wide distribution of power generation units and geographical constraints,they are managed and managed by wire and cable.Unrealistic.At present,thanks to the rapid development of the Internet of Things technology and "cloud" service platform technology in recent years,it has become possible to establish an efficient,flexible and convenient energy monitoring and management method.This article first describes the background and current status of the subject,and then designs the networking scheme of the single-phase photovoltaic grid-connected system,compares various wireless communication technologies such as Zigbee,BLE Mesh,Wi Fi and GPRS,and chooses to use the Zigbee wireless sensor network.combined with the NB-Io T intelligent gateway,the monitored photovoltaic power plant data is uploaded to the One NET cloud server to realize the network monitoring function of the photovoltaic grid-connected system.Next,the topology of the single-phase photovoltaic grid-connected inverter is analyzed,and the two-stage micro photovoltaic grid-connected structure with high flexibility is selected.The DC-DC link of the previous stage adopts an active clamping inverter with a high-frequency isolation transformer Excited converter realizes boost and MPPT control;the DC-AC link of the rear stage adopts double Buck full-bridge inverter to realize the function of electric energy conversion;then filters out the higher harmonics through the LCL filter and connects to the power g rid;finally Simulation experiments on Matlab/Simulink platform verify the effectiveness of MPPT algorithm and grid-connected control strategy.Finally,to build the hardware platform of the system,in order to meet the computing needs of the system,TMS320F28335 of TI Company was selected as the main chip of the control unit.According to the system’s main power circuit and measurement requirements,the device selection and design of the switch tube,drive circuit and monitoring circuit are ca rried out respectively.At the same time,the wireless intelligent gateway circuit and the "cloud" service platform are designed according to the system’s networking function.In terms of software,the overall process of the single-phase photovoltaic grid-connected system,the interruption monitoring process and the overall process of the intelligent gateway are designed.Through the system joint debugging experiment on the prototype,the relevant experimental results are obtained,which shows that the overall scheme of the system is feasible.