scholarly journals Fault Diagnostic Methodology for Grid-Connected Photovoltaic Systems

2021 ◽  
Vol 2 (2) ◽  
pp. 10-30
Author(s):  
Proenza Y. Roger ◽  
Camejo C. José Emilio ◽  
Ramos H. Rubén

This research focuses on the design of a fault diagnosis methodology to contribute to the improvement of efficiency, maintainability and availability indicators of Grid-Connected Photovoltaic Systems. To achieve this, we start from the study of the mathematical model of the photovoltaic generator, then, a procedure is performed to quantify the operational losses of the photovoltaic generator and adjust the mathematical model of this to the real conditions of the system, through a polynomial adjustment. A real system of nominal power 7.5 kWp installed in the Solar Energy Research Center of the province of Santiago de Cuba is used to evaluate the proposed methodology. Based on the results obtained, the proposed approach is validated to demonstrate that it successfully supervises the system. The methodology was able to detect and identify 100% of the simulated failures and the tests carried out had a maximum false alarm rate of 0.22%, evidencing its capacity.

2021 ◽  
Vol 2 (2) ◽  
pp. 47-53
Author(s):  
Proenza Y. Roger ◽  
Camejo C. José Emilio ◽  
Ramos H. Rubén

A procedure is presented for the quantification of the degradation index of Photovoltaic Generators, based on the quantification of the operational losses inherent in the system, which allows maintaining the nominal operating conditions and by the warranty terms of the photovoltaic generator. A photovoltaic generator connected to the network with a nominal power of 7.5 kWp, installed in the Solar Energy Research Center of Santiago de Cuba, is used to evaluate and validate the procedure. The starting point is the mathematical model of the photovoltaic generator, then the operational losses of the photovoltaic generator are quantified and the mathematical model is adjusted to real conditions, through a polynomial adjustment.  The results obtained show that the photovoltaic generator presents deviations in terms of the nominal power generation, because the operational losses are 7% with respect to the values ​​given by the manufacturer.


2013 ◽  
Vol 790 ◽  
pp. 160-164
Author(s):  
Yong An Ao ◽  
Gang Li ◽  
Wei Xin Kong ◽  
Qi Feng

The research, based on combination system of solar energy and municipal heating network, studied the running scheme of combination system of solar energy and municipal heating network through ways of experiments and theoretical calculation of the mathematical model. Firstly, the research established mathematical model of heat equilibrium of the combination system of solar energy and municipal heating network; secondly, keeping the indoor heat load steady, compared the dynamic heat load provided by solar collector with that needed by heated room at the same time,determined time spans of the network stopping service and the heat load added by the network within 24 h. In the research we took a heating period in a typical room in Shenyang for example, under the conditions of low temperature floor radiant with heating index standard of 50W/ m2 and 50°C of the average supplied water temperature, 40 °C of the return water temperature, calculated and verified the established mathematical model. The results include: when the heat load provided by solar collector is greater or less than the heat needed by the room, how many heat amount should be supplied by the running network and the amount of water flow within the network pipes correspondingly, and how long the network runs or stops. The final conclusions include: whether the running scheme of the combination system can save energy? the conditions of energy saving in running a combination system, and whether the system can bring environmental benefits.


2012 ◽  
Vol 239-240 ◽  
pp. 721-725
Author(s):  
Wen Rong Zheng ◽  
Shu Zong Wang

Intermittent fault is the main factor for the raise of false alarm during the process of the detection in built-in test (BIT). Two-state Markov model and three-state Markov model for test is built for system fault diagnosis with BIT. According to the application of BIT in some complex system, a comparison of the false alarm rate between two-state Markov model and three-state Markov model is present, which shows we can reduce the false alarm rate (FAR) and improve fault detection rate by using three-state Markov model in BIT.


2015 ◽  
Vol 9 (1) ◽  
pp. 193-199 ◽  
Author(s):  
Shi Xudong ◽  
Li Hongguang ◽  
Wang Ruowen ◽  
Xu Meng

Igniter is an important part of aircraft engine, which should be reliable to ensure safety. Spark frequency disorder is common fault to the aviation ignition device, and it is great hidden danger to the aircraft engine. To guarantee the safety and reliability of aviation igniter, the fault mechanism of the aviation ignition spark frequency disorder is researched in this paper. The factors which will result in spark frequency disorder are studied, and the mathematical model of the ignition circuit and circuit simulation are presented, which lays the foundation for the follow-up research on the design of aviation ignition and the fault diagnosis.


2013 ◽  
Vol 740 ◽  
pp. 782-786
Author(s):  
Guo Liang Zou ◽  
Xin Nan Lou

To implement the objective of steady operation of the marine observation buoy system on the sea throughout the year,based on energy balance between supply and demand, this paper presents the mathematical model of solar energy power supply system derived from double batteries switching technology. The batteries are divided into main batteries and auxiliary batteries. The main batteries are used regularly and the auxiliary batteries are used in periodic rainy weather. The main advantage of this model is that the capacity of auxiliary batteries can be dynamic calculated based on the numbers of maximum continuous rainy days and minimum intervals between rainy days. The batteries capacity is sufficient but not redundant. This design project has been tested on marine buoy and the accuracy of the model is splendid for most engineering projects.


2013 ◽  
Vol 347-350 ◽  
pp. 1430-1434
Author(s):  
Wei Wang ◽  
Hai Fang Yu ◽  
Chang Fu Zheng ◽  
Yan Shi Zhao

In order to make a diagnosis of wind turbine failure, the mathematical model of the wind turbine should be prepared. This model can provide a theoretical basis for fault diagnosis. establishing the mathematical model of the main part of the generator being discussed on theoretical ,including the tower vibration, wind wheel and drive chain, the moment of inertia of the wind turbine and the synchronous generator voltage equation model in dq coordinate system. Its main focus on the demand for wind turbine fault diagnosis.


2014 ◽  
Vol 1061-1062 ◽  
pp. 716-719
Author(s):  
Feng Hua Zou ◽  
Hong Zhang

In view of a certain type of electrical equipment whose failure causes and failure is not a one-to-one relationship between signs, this paper established the mathematical model of fault diagnosis adopting the fuzzy reasoning mechanism. At the same time, we designed the system overall scheme of fault diagnosis according to the system of the diagnosis process and realized diagnosis function of system by using vc + + programming language. Through specific examples verify that the system has the ability of fault diagnosis of electric equipment for a certain type.


2012 ◽  
Vol 512-515 ◽  
pp. 194-197
Author(s):  
Ying Ling Cai ◽  
Yin Long Wu ◽  
Hua Zhang ◽  
Ji Wei Li

Through the study on the project, we can easily find that if we do not need heat the whole day, adopting the dynamic load method to calculate the heating load is more advisable compared to adopting a steady-state one, especially when we select the equipment. After establishing the mathematical model of the project, under the premise of meeting the heating load, considered the economy, the optimal solar collector area of this project is 11.1 square meters. In addition, through simulating the project, we can learn that the best azimuth of solar collectors in Shanghai is south by east 22.5 °.


2014 ◽  
Vol 6 ◽  
pp. 281216 ◽  
Author(s):  
Honggen Zhou ◽  
Xuwen Jing ◽  
Lei Wang ◽  
Kaiyun Dai ◽  
Jia Yongpeng

High speed cutting process is a very complicated process; cutting parameters have a significant effect on cutting process and play a key role in the process of product manufacturing. The overall scheme of high speed cutting parameter optimization and its fault diagnosis have been introduced. The mathematical model of the selected cutting parameters was established and the optimized parameters were obtained by combining the experimental design with the technology of data processing. The statistical description of high speed cutting process control was introduced and the fault diagnosis model of cutting parameter optimization by using the neural network was proposed. Finally, the mathematical model in the present study is validated with a numerical example. The results show that the present method solved the problem of poor universality of high speed cutting data effectively and avoided the inaccuracy of physical and chemical mechanism research. Meanwhile, the present study prevents the passive checks of the cutting and gets better diagnosis of the complicated cutting fault type.


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