Fault Characteristic Analysis And Fault Location Method Of Photovoltaic Array

Photovoltaic power generation is a green and environmentally friendly development method that converts solar energy into electricity.Photovoltaic systems have been widely used in a large number of power production industries.Photovoltaic arrays are generally installed outdoors,and due to various environmental factors,component failures in the photovoltaic array will occur frequently.If the failure problem cannot be resolved in a timely manner,it may lead to the burning of components in the array or cause a fire,and reduce the output efficiency of the array.Therefore,it is of great significance to quickly and accurately locate faulty components and reduce the impact of faulty components on the output characteristics of photovoltaic arrays.This article will analyze the characteristics of four typical faults: shadow shielding,open circuit fault,short circuit fault,and abnormal aging,and achieve the location of faulty components.In this thesis,a single exponential and five parameter circuit model of photovoltaic cells is established firstly.By analyzing the circuit model,the output characteristics of photovoltaic cells are simulated in MATLAB/simulink,and their output characteristics are analyzed when the ambient temperature and radiation intensity change individually;Comparative analysis of current common photovoltaic array structures was conducted to determine the photovoltaic array structure used in this thesis.Secondly,the common fault types and sources of photovoltaic modules in photovoltaic power generation systems are analyzed.Four typical faults,including shadow shielding,open circuit fault,short circuit fault,and abnormal aging,are simulated and analyzed by MATLAB.Through comparative analysis of the results,the impact of different faults on the characteristic parameters of the module is determined;Explored how to reduce the impact of faults on output characteristics.Based on the characteristics of single and composite faults,in order to further improve the output power of photovoltaic arrays,reduce the frequency and cost of manual maintenance,finally provided guidance suggestions for improvement and response.Then,a fault location method based on the combination of sensor location method and parameter estimation method is proposed.Determine the branch of the faulty component according to the change in the output current of the current sensor;The module position of the faulty component is determined by the module voltage collected by the voltage sensor,and the voltage values of each region in the module are calculated and compared with the reference voltage to determine the region of the faulty component;The location of the faulty component can be accurately determined by the variation of the characteristic parameters of each component in the area where the fault is located.This fault location method can not only locate fault components in a single region,but also accurately locate fault components in multiple regions.Finally,based on the proposed fault location structure,corresponding voltage sensors and current sensors are added to the constructed photovoltaic array structure,and simulation analysis is conducted for single faults such as open circuit,short circuit,shadow shielding,etc.In addition,simulation simulations are conducted for multiple faults located in the same branch,and multiple faults located in different branches,verifying the correctness of the photovoltaic array fault location method proposed in this article.