International Journal of Hydrogen Energy, Vol.42, No.22, 14968-14979, 2017
Reliability assessment of a stand-alone wind-hydrogen energy conversion system based on thermal analysis
Due to the stochastic behavior of the wind speed, accessing the wind energy would be problematic in some critical moments. One feasible solution lies in the use of wind turbines to produce hydrogen through an electrolyzer and by using wind-hydrogen hybrid systems. However, many of the issues related to these systems should be investigated to make landmark decisions about their performance. For instance, there is a lack of study on the reliability assessment of the wind-hydrogen systems; for this purpose, the main objective of this study is to evaluate the reliability of a stand-alone wind-hydrogen energy conversion system unconnected to the grid. The proposed system consists of two major parts: the rectifier and the buck converter. The primary task of the rectifier is to rectify the wind turbine output voltage to a constant DC voltage. Additionally, the buck converter is responsible to reduce the voltage level to a 48 V voltage, which meets the voltage requirement of the 3.6 kW electrolyzer. The results of the performed simulations showed that the rectifier is under more thermal stresses than the buck converter. The predicted mean time to failure (MTTF) of the hybrid system is approximately 7.6 years, and this estimation can affect the maintenance and refurbishment costs. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Reliability assessment;Wind-hydrogen hybrid system;Thermal analysis;MIL-HDBK-217;Buck converter