Design Of Photovoltaic Combiner Acquisition System Based On PIC16F1947

Solar energy is the one of the most effective energy types to solve the energy crisis and environmental pollution.The photovoltaic industry has been widely developed recently.The combiner box is a key equipment in the photovoltaic power generation system,which is connected with the PV array and the inverter and has been puts forward higher requirements for the development of the sampling channel and the detection precision.However,the traditional photovoltaic combiner box can not meet the demand of existing PV system because it features the slow processing speed,large measurement error and can not carry out remote monitoring.Thus,it will be of much significance to do the research of photovoltaic combiner box acquisition system and it plays an important role in the field of photovoltaic power generation.This dissertation designs the photovoltaic combiner box acquisition system based on PIC 16F1947,the main contents include:First of all,it describes the research of photovoltaic power generation at home and abroad in terms of the basic principle and characteristics of PV module power generation,the principle of photovoltaic combiner box.On the basis of these,this dissertation introduces the principle of the solar collector,analyzes the problems existing in the traditional combiner box.Secondly,the hardware part of the photovoltaic combiner box acquisition system is designed.The system achieve the functions of acquisition,which based on the the acquisition module,power module,optocoupler isolation module,RS-485 transmission module and temperature monitoring module and other hardware Module by seleting the low power microcontroller PIC 16F1947 as the core control chip,the Hall current sensor as the main acquisition device.Furthermore,the software design is completed on the basis of the achievement of the hardware,which proposes the two-point successive correction self-calibration algorithm based on the least square method.The accurate calibration of the calibration parameters is realized.The data communication protocol of PV convergence box is developed in the following according to the Modbus-RTU protocol in the communication standard of RS-485.Finally,the calibration and monitoring system based on the LabVIEW is designed to achieve the real-time monitoring of PV combiner box acquisition system.Finally,the uncertainty of calibration relative error in the system is evaluated.The accuracy of the calibration algorithm is verified after the analysis of the source of the measurement error and the establishment of the calibration experiment platform.Then,the data collected from the PV pool are analyzed.The data collected on the site indicate that the designed system is stable and meets the design requirements.The experimental results show that the experimental results show that the calibration system is in accordance with the standard CNCA/CTS0001-2011A "Technical Requirements of PV Combiner Assemblies".