Application Of DC Power Carrier In Photovoltaic Module Malfunction Monitoring System

In this paper,the DC power carrier communication technology is applied to the photovoltaic power generation system.As a technical methods to monitor the fault of photovoltaic modules,the communication structure of the carrier communication current loop is applied to the structural design of the monitoring system.A power carrier communication device and a communication structure of monitoring system are designed.The theoretical knowledge and key technologies applied in the design process are analyzed.In this paper,power line carrier communication technology means that using the original power lines in the photovoltaic power generation system to replace the communication lines to complete the data signal transmission,so that the communication lines don't need to decorate,and the cost can be saved.Power carrier communication technology is divided into AC and DC.This paper is the direct current part of photovoltaic modules in photovoltaic power generation system,so DC power carrier communication technology is applied.This paper analyzes the power generation principle of photovoltaic cells and builds a photovoltaic cell model for simulation in MATLAB/Simulink.To Analysis several different faults of photovoltaic modules,and theoretically obtains that the influence of different faults on the output characteristics of photovoltaic modules.By comparing the voltage and current data collected by the carrier communication device with the standard data output by the photovoltaic module,the fault of the photovoltaic module can be judged.Using 2ASK signal modulation and demodulation mode for signal modulation,and built the simulation model in MATLAB/Simulink to verify the feasibility of this method.Under the premise of theoretical calculation and simulation verification,the communication system structure is designed according to the distribution structure of photovoltaic power station,and the carrier current loop communication structure is applied to photovoltaic power station.The hardware circuit of the corresponding function module is designed,and STM32F373 series single-chip microcomputer of ARM company is selected as the main control chip of the monitoring module.The experimental platform was built to test the waveform signal of the carrier communication device and the carrier current loop communication structure.The final carrier frequency was selected according to the change of signal amplitude in the experiment,and the communication data were compared by the upper computer and the photovoltaic simulator to verify the correctness and practicability of the design.