Student Projects
University: Aalborg University, Denmark
Team Member(s): Daniel Díaz González and Robert Diosi
Faculty Advisors: Remus Teodorescu and Maciej Swierczynski
Email Address: ddg.melou (at) gmail.com
Title: ACCELERATED LIFE TESTING AND LIFETIME PREDICTION OF LITHIUM ION BATTERIES CONNECTED TO WIND TURBINES
Products: MATLAB/Simulink and LabView
Description:
The future plans regarding the increase of the share of wind power in the Electrical Grid point out towards major challenges that this wind power integration implies:
the need to transform the current wind parks into reliable power generation units, capable of providing the base load, covered by conventional generation units, at the moment.
The major obstacle in the way of a high scale wind integration into the Grid is represented by the unpredictable behavior of the wind. A solution to diminish the wind power units
dependability upon the wind unpredictability can be represented by Battery Energy Storage Systems (BES). One of the most important requirements for a fruitful BES
integration into Wind Power Systems is a correct estimation of their lifetime.
The present work is focused on the lifetime estimation of Lithium Iron Phosphate cells, by applying two accelerating factors: high temperatures and high current rates.
The laboratory work was performed by applying to the testing setup a state of charge (SOC) input signal corresponding to the simulation of the Forecast Improvement
Service in Simulink. The input SOC contained data corresponding to 1 entire year of simulations. Two groups of LiFePO4 were tested at 50 and 40 °C, respectively and at
an applied current rate corresponding to 2 C. The experimentally acquired data was used in order to obtain the parameters of the equivalent battery model, whose parameters
were modified in order to account for ageing processes as well in the simulation, which finally provided the lifetime of a certain BES size, operating under a userdefined temperature.
