On-line Monitoring System Of Photovoltaic Array Based On Open Source Software And Hardware Technology

Solar energy is a clean and renewable energy,and photovoltaic(PV)power generation has become one of the most promising new energy sources.However,the PV power plants generally work in outdoor harsh environment,and PV panels are inevitably to damaged.Therefore,an effective monitoring system is necessary to evaluate the performance of PV power plants.An on-line monitoring system with PV array monitoring and real-time fault diagnosis is proposed,and the system based on open-source technology is presented for monitoring and managing the PV power plant effectively and economically.The proposed monitoring system consists of three parts:data acquisition and transmission,data gateway,and on-line monitoring center.The data acquisition and transmission part includes weather data collection module and PV array data acquisition module,which are distributed on the monitoring nodes of each PV array.The weather data collection module is designed based on the low-power microcontrollers MSP430 series,which mainly obtains the operating parameters such as the irradiance of the PV array,the temperature of the PV modules,the environmental temperature and humidity.The data transmission is implemented via the Bluetooth communication network between the two modules.STM32 is adopted as the control unit of the PV array data acquisition module to obtain the PV array voltage,current parameters.Then PV array data acquisition module upload all data to the data gateway through WiFi.The open-source hardware Raspberry Pi 3 is applied as the platform of the data gateway.The data gateway mainly implements device information collection,data visualization,GPS positioning,database management,and video surveillance.The user interface of the data gateway is designed based on the Qt framework.Data gateway communicates with on-line monitoring center over the Internet by 4G module.In addition,the on-line monitoring center based on the open IoT platform Ubidots is built for displaying data of the PV arrays.The on-line monitoring center website is developed based on the open-source PHP framework Laravel.The data received from the data gateway is analyzed and processed for user management,data visualization,fault early warning and video surveillance display.In addition,the website is deployed on Tencent cloud server.Furthermore,users can browse the monitored information of website through the WeChat Official Account Admin Platform.A fault diagnosis approach based on Firefly Algorithm and Support Vector Machine(FA-SVM)is proposed in this thesis to obtain a high-accuracy PV array fault diagnosis model.The model is established by optimizing the SVM parameters and implemented in the data gateway for real-time fault detection and classification.The experimental results show that the fault diagnosis method can achieve a relatively high fault classification accuracy,and the average of total accuracy is about 98%.The open source hardware and software technology is adopted to develop the PV array online monitoring system.The data acquisition part can collect the working status information and environmental parameters of the PV array in real time.Users can browse the PV array operation information at the data gateway,data monitoring center website and WeChat.Once fault occurs,the system can promptly inform users in several ways.The experimental results indicate that the designed monitoring system can run stably and achieve the expected goals.