Automatic supervision of Pv systems and degradation analysis of thin film PV modules
Monitoring and regular performance analysis of Grid-Connected Photovoltaic (GCPV) systems are of primal importance in order to ensure an optimal energy harvesting and reliable power production at competitive costs. Main faults in GCPV systems are caused by short-circuits or open-circuits in PV modul...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | España |
| Institución: | CBUC, CESCA |
| Repositorio: | TDR. Tesis Doctorales en Red |
| OAI Identifier: | oai:www.tdx.cat:10803/461180 |
| Acceso en línea: | http://hdl.handle.net/10803/461180 https://dx.doi.org/10.5821/dissertation-2117-113678 |
| Access Level: | acceso abierto |
| Palabra clave: | Àrees temàtiques de la UPC::Enginyeria electrònica 004 620 |
| Sumario: | Monitoring and regular performance analysis of Grid-Connected Photovoltaic (GCPV) systems are of primal importance in order to ensure an optimal energy harvesting and reliable power production at competitive costs. Main faults in GCPV systems are caused by short-circuits or open-circuits in PV modules, inverter disconnections, PV module degradation and the presence of shadows on the PV array plane. Detecting these faults can minimize generated losses by reducing the time in which the PV system is working below its optimum point of power generation. In addition, the degradation of Tin Film PV (TFPV) modules under outdoor exposure is still not fully understood and is currently object of research. A better understanding on this topic would be important for selecting the best PV technology for the appropriate climatic condition and for improving the reliability and performance of PV systems. Simulations play a crucial role in both outdoor behaviour forecasting and automatic fault detection of GCPV systems. Two PV module/array models have been used in the present thesis in order to simulate the outputs of GCPV systems of different topologies and solar cell technologies, as well as in the fault detection procedure. Moreover, five different algorithms were used for estimating the unknown parameters of both PV models in order to see how these estimated parameters affect their accuracy in reproducing the outdoor behaviour of three GCPV systems. The obtained results show that the metaheuristic algorithms are more efficient than the Levenberg-Marquardt algorithm (LMA) especially in bad weather conditions and both PV models perform well when used in the automatic fault detection procedure. A new approach for automatic supervision and remote fault detection of GCPV systems by means of OPC technology-based monitoring is presented in this thesis. The fault detection procedure used for the diagnosis of GCPV systems is based on the analysis of the current and voltage indicators evaluated also from monitored data and expected values of current and voltage obtained from the model of the PV generator. Three GCPV systems having different sizes, topologies and cell technologies have been used for the experimental validation of the proposed fault detection method. The analysis of current and voltage indicators has demonstrated effectiveness in the detection of most probable faults occurred in the PV arrays in real time. Furthermore, obtained results show that the combination of OPC monitoring along with the proposed fault detection procedure is a robust tool which can be very useful in the field of remote supervision and diagnosis of GCPV systems. Finally, the study of degradation issues of TFPV modules corresponding to four technologies: a-Si:H, a-Si:H/µc-Si:H, CIS and CdTe, deployed under outdoor conditions for long term exposure is also addressed in the present thesis. The impact of the degradation on the output power of the PV modules is analysed, in order to determine their annual degradation rate and their stabilization period. The degradation rate is obtained through a procedure based on the evolution of the module effective peak power over time. The stabilization period is evaluated by means of two methods: the evolution of DC-output power of the PV module, and the power-irradiance technique. The obtained results show that the CIS PV module is the most stable compared to the other technologies, when deployed under Continental-Mediterranean Climate. The a-Si:H and a-Si:H/µc-Si:H PV modules also perform quite well, showing degradation rates and stabilization periods similar to the expectations. The CdTe module shows poor performances, with the highest degradation rate, and long stabilization period of 32 months. Lastly, the parameter extraction technique has been also applied to analyse the evolution of model parameters for a-Si:H and a-Si:H/µc-Si:H arrays working in outdoor conditions for long term exposure. |
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