Design On Photovoltaic Module Health Assement Device

Solar energy is currently the most widely used clean energy,and it is inexhaustible.As the main power generation device,photovoltaic modules play an important role in solar power generation.However,the current photovoltaic modules have many faults such as hot spots,shielding,and hidden cracks in the actual power generation process,which affect their power generation efficiency and cause power attenuation.At the same time,the current research on the impact of photovoltaic module power attenuation and health status mostly stays on a single factor,and there is no device that can comprehensively evaluate the health status of photovoltaic modules.In actual photovoltaic power generation,the electrical data of photovoltaic components and current environmental data determine the actual power generation of the current photovoltaic components,and the power generation is an important indicator to measure the attenuation of photovoltaic components.At the same time,among the various abnormalities of photovoltaic modules,the hot spot effect has a greater impact on the power generation of photovoltaic modules,and it is also easy to cause fires and other disasters.Therefore,this paper develops a portable integrated device that can calculate the attenuation of electrical energy through environmental data and electrical data of photovoltaic modules;it can detect hot spots;it can comprehensively evaluate the health of photovoltaic modules.The main work of this paper includes:(1)Provide the overall function planning requirements of the photovoltaic module health assessment device.The health assessment device is mainly composed of two parts: hardware and software.The hardware part is mainly composed of core development board,power supply equipment,output equipment,input equipment and network equipment.The input device is mainly an infrared thermal imager,which is used to shoot hot spot images.Network equipment is used to obtain electrical and environmental data.The software part is mainly divided into three modules: power attenuation calculation,hot spot detection and health assessment.(2)Aiming at the actual situation of photovoltaic power plants,this paper proposes a method for calculating the power attenuation of photovoltaic modules that can be applied on site,and completes the power attenuation rate calculation module of the health assessment device.The power attenuation rate of photovoltaic modules can be approximated as the attenuation percentage between the actual maximum power point power and the theoretical maximum power point power.In actual photovoltaic power plants,the theoretical maximum power point cannot be directly obtained.Therefore,this paper studies the power generation principle of photovoltaic modules and establishes a mathematical model of photovoltaic module power generation.At the same time,considering the influence of the actual environment on the theoretical maximum power point,two models of compensation coefficient model and power prediction model are established to calculate the theoretical maximum power that the photovoltaic module should generate in the actual environment.At present,the back-end of photovoltaic modules will be connected to the module optimizer in actual power generation,so that the photovoltaic modules work at the maximum power point.Therefore,the actual power generation of the photovoltaic module can be directly read as the actual maximum power generation,and then the power attenuation rate can be calculated.(3)Aiming at the hot spot characteristics of photovoltaic modules,this paper proposes two algorithms for hot spot detection: traditional computer vision MSER algorithm and machine learning K-Means algorithm.At the same time,since hot spots are difficult to form in a short time,this paper uses occlusion to simulate the formation of hot spots.Comparing the effect of the MSER algorithm K-Means algorithm in the hot spot detection,it is found that the K-Means algorithm can be used in the hot spot detection module to complete the work better,and then the K-Means algorithm is packaged to develop the photovoltaic module hot spot detection module.(4)Aiming at the health status of photovoltaic modules,this paper proposes a photovoltaic module health system and completes the photovoltaic module health assessment module.This paper studies the influence of the simulated hot spots on the power generation of photovoltaic modules and the IV characteristic curve,and proposes two evaluation indicators,the power loss ratio and the maximum power point shift.At the same time,the power loss ratio and the maximum power point shift are two evaluation indicators.Quantitative integration calculates the health of photovoltaic modules,and establishes a photovoltaic module health system.(5)Test the photovoltaic module health assessment device.Since the test of this device requires the help of an actual photovoltaic power station platform,an experimental test platform for photovoltaic modules was built.This platform is mainly composed of photovoltaic module arrays,data collectors,environmental testing equipment,host computer software,and communication protocols for communication between devices.Finally,based on this platform,various performance indicators of the photovoltaic module health assessment device are tested.