Research On Large-scale PV Array Power Simulation System And Fault Diagnosis Technology

With the development of science and technology and technological innovation, PV power generation technology has been widespread used in the industries of electric power production. But with the development of PV industry, the life of the PV power station into a recession, problems are coming. In the study of the theory of the PV power generation system, there are two aspects need to be paid attention mainly: one is how to improve the working efficiency of the system and reduce the cost; the second is how to reduce the failure rate. The fault mainly comes from short circuit, open circuit, shade, hot spot effect and their own performance degradation, and its basic reason boils down to voltage disturbance. For solving this kind of accident, fault diagnosis for PV array technology research is needed. At the same time, a reasonable and effective photovoltaic power station monitoring system should be designed to improve the efficiency of the power system and reduce the system maintenance costs.In this paper, combined with the project of National Natural Science Foundation of China(No. 51566015) and the project of Qinghai Science and Technology Department(No. 2012- G- Y25A-4 and 2012 GX- 212), carried out the paper work of "Research on large-scale PV array power simulation system and fault diagnosis technology". Main studies and discusses are listed as below:1. Through the research and comparison on the PV array connection structure, the array arrangement of this paper is determined. Through analyzing the sources of fault and fault types of PV array, the test method of fault diagnosis and the research status is summarized. The fault diagnosis method of this paper is determined comparing the advantages and disadvantages.2. A new PV array fault detection and location method is proposed, namely global partitioned gradually approximation method. Algorithm is based on matrix processing. On the depth of data mining, voltage fluctuation of PV modules is evaluated to judge whether there is a fault. Based on Matlab software, the algorithm is realized. Simulation on data matrix of 100 x 100 is verified. Simulation results show that the algorithm can effectively detect and locate the fault.3. User requirements and functional requirements of PV power station monitoring system are analyzed. Thus the functional design scheme of simulation system of this paper is determined, including data display and storage, system and user management, fault diagnosis, data statistics, etc.4. Aimed at the function demand of the PV power station monitoring system, based on the LabVIEW application development environment, the system function and interface of simulation system are developed and designed, which is reliable, maintainable and high plasticity.