National center for research and development of technology

Ecatepec, Mexico

National center for research and development of technology

Ecatepec, Mexico
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De Leon-Aldaco S.E.,National Center for Research and Development of Technology | Calleja H.,National Center for Research and Development of Technology | Chan F.,University of Quintana Roo | Jimenez-Grajales H.R.,Electric Research Institute of Mexico
IEEE Transactions on Power Electronics | Year: 2013

This paper presents the reliability analysis of a push-pull converter intended for connection to a 125-W photovoltaic (PV) panel. Four prototypes of the converter were built and tested, using transistors with different ratings. Failure rates were calculated using theMIL HDBK 217 and the IEC TR 62380 procedures. In the latter case, the predictionwas performed taking into account an annual mission profile obtained from the intended installation site, in an area with desert climate temperatures. Failure rate results obtained withMIL HDBK 217 show small differences among the converters, the best performance obtained from the prototype with the lowest on-resistance. Results obtained with IEC TR 62380 indicate that thermal cycles have a significant effect in reliability performance, and should be considered carefully, because PV systems often see large temperature variations.With both procedures, the failure rate contributions from magnetic devices were higher than expected. © 2013 IEEE.


Calleja H.,National Center for Research and Development of Technology | Chan F.,University of Quintana Roo
Journal of Power Electronics | Year: 2010

This paper presents the approach followed to develop a course that introduces reliability into the design of power electronics converters. The course is part of the curriculum of a master of science in electrical engineering program, and it is aimed at providing reliability tools that can be used in a straightforward manner, while avoiding the mathematical intricacies. The reliability calculations are performed according to the Military Handbook 217, using the evaluation version of a commercial software package which greatly reduces the computational burden usually associated with this task. The course assessment shows that, after attending the course, students were able to improve the mean time between failures in a power-electronics converter, from a minimum of 5%, up to 100%.


Correa-Betanzo C.,National center for research and development of technology | Calleja H.,National center for research and development of technology | Lizarraga A.,National center for research and development of technology
Solar Energy | Year: 2016

Currently, there is an ongoing trend to promote photovoltaic systems as they are a sustainable option for power generation. However, the efficiency conversion of solar energy into electric energy can diminish due to adverse environmental conditions and the performance of power processing circuits. Several approaches have been proposed to mitigate the negative effects of high temperatures and light load operation on power converters. Nonetheless, in areas with hot climates and overcast conditions, the efficiency consequences must be specifically evaluated. In this paper, the assessment of an approach to enhance the converter efficiency at low power levels is presented. The approach employs hybrid-switches within a transformerless converter topology, in such a way that, under light-load operational conditions, soft-switching is achieved. The technique is evaluated for ten specific sites from which there is ample meteorological data available. Results indicate that a 1.35 percent increase in overall efficiency can be obtained with the proposed approach, with an annual surplus energy of 7220 W h for a 1 kW system. © 2016 Elsevier Ltd


de Leon S.,National center for research and development of technology | Calleja H.,National center for research and development of technology | Mina J.,National center for research and development of technology
Microelectronics Reliability | Year: 2015

In areas with hot weather, photovoltaic systems can be used to help relieve the peak demand caused by air conditioning equipment. Users, however, are reluctant to invest in solar technology, arguing that the equipment commercially available is unreliable because it was developed for others environments. In this paper, the reliability assessment of a DC/DC converter aimed at PV applications is presented. The reliability estimation was performed following the FIDES methodology, taking into account seasonal mission profiles developed for five specific sites for which there is meteorological data available. The goal was to identify the most failure prone components, and the dominant stress factors. It was found that the smallest contribution to the failure rate occurs during winter. The largest contribution occurs in spring or summer, depending on the site. In the converter, the most failure-prone components were the diodes, which contributed with about 70% of the overall failure rate. © 2015 Elsevier Ltd.

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