Lithium-ion battery thermal-electrochemical model-based state estimation using orthogonal collocation and a modified extended Kalman filter

This paper investigates the state estimation of a high-fidelity spatially resolved thermal- electrochemical lithium-ion battery model commonly referred to as the pseudo two-dimensional model. The partial-differential algebraic equations (PDAEs) constituting the model are spatially discretised using Chebyshev orthogonal collocation enabling fast and accurate simulations up to high C-rates. This implementation of the pseudo-2D model is then used in combination with an extended Kalman filter algorithm for differential-algebraic equations to estimate the states of the model. The state estimation algorithm is able to rapidly recover the model states from current, voltage and temperature measurements. Results show that the error on the state estimate falls below 1 % in less than 200 s despite a 30 % error on battery initial state-of-charge and additive measurement noise with 10 mV and 0.5 K standard deviations.Comment: Submitted to the Journal of Power Source

Identifiability and parameter estimation of the single particle lithium-ion battery model

This paper investigates the identifiability and estimation of the parameters of the single particle model (SPM) for lithium-ion battery simulation. Identifiability is addressed both in principle and in practice. The approach begins by grouping parameters and partially non-dimensionalising the SPM to determine the maximum expected degrees of freedom in the problem. We discover that, excluding open circuit voltage, there are only six independent parameters. We then examine the structural identifiability by considering whether the transfer function of the linearised SPM is unique. It is found that the model is unique provided that the electrode open circuit voltage functions have a known non-zero gradient, the parameters are ordered, and the electrode kinetics are lumped into a single charge transfer resistance parameter. We then demonstrate the practical estimation of model parameters from measured frequency-domain experimental electrochemical impedance spectroscopy (EIS) data, and show additionally that the parametrised model provides good predictive capabilities in the time domain, exhibiting a maximum voltage error of 20 mV between model and experiment over a 10 minute dynamic discharge.Comment: 16 pages, 9 figures, pre-print submitted to the IEEE Transactions on Control Systems Technolog

Modular converter system for low-cost off-grid energy storage using second life Li-ion batteries

Lithium ion batteries are promising for small off- grid energy storage applications in developing countries because of their high energy density and long life. However, costs are prohibitive. Instead, we consider 'used' Li-ion batteries for this application, finding experimentally that many discarded laptop cells, for example, still have good capacity and cycle life. In order to make safe and optimal use of such cells, we present a modular power management system using a separate power converter for every cell. This novel approach allows individual batteries to be used to their full capacity. The power converters operate in voltage droop control mode to provide easy charge balancing and implement a battery management system to estimate the capacity of each cell, as we demonstrate experimentally.Comment: Presented at IEEE GHTC Oct 10-14, 2014, Silicon Valle

Energy allocation and behaviour in the growing broiler chicken

Broiler chickens are increasingly at the forefront of global meat production but the consequences of fast growth and selection for an increase in body mass on bird health are an ongoing concern for industry and consumers. To better understand the implications of selection we evaluated energetics and behaviour over the 6-week hatch-to-slaughter developmental period in a commercial broiler. The effect of posture on resting metabolic rate becomes increasingly significant as broilers grow, as standing became more energetically expensive than sitting. The proportion of overall metabolic rate accounted for by locomotor behaviour decreased over development, corresponding to declining activity levels, mean and peak walking speeds. These data are consistent with the inference that broilers allocate energy to activity within a constrained metabolic budget and that there is a reducing metabolic scope for exercise throughout their development. Comparison with similarly sized galliforms reveals that locomotion is relatively energetically expensive in broilers

Transgenesis in Animal Agriculture: Addressing Animal Health and Welfare Concerns

The US Food and Drug Administration’s final Guidance for Industry on the regulation of transgenesis in animal agriculture has paved the way for the commercialization of genetically engineered (GE) farm animals. The production-related diseases associated with extant breeding technologies are reviewed, as well as the predictable welfare consequences of continued emphasis on prolificacy at the potential expense of physical fitness. Areas in which biotechnology could be used to improve the welfare of animals while maintaining profitability are explored along with regulatory schema to improve agency integration in GE animal oversight

Spectral_li-ion_SPM: Initial release

Spectral li-ion SPM is a MATLAB code that solves the so-called lithium-ion battery Single Particle Model (SPM) using spectral numerical methods

Evaluation of sludge from paper recycling as bedding material for broilers

Several materials have been used as bedding substrates in broiler production. In this work, the sludge from paper recycling was tested for its potential use as litter material and was compared with wood shavings. Moisture content, apparent density, and water-holding capacity were measured and characterized in both materials. Later, 192 male broiler chickens were distributed among 16 experimental pens, 8 of which contained wood shavings as bedding material and 8 of which contained the sludge. growth rate, consumption, tonic immobility, gait score, breast lesions, foot pad dermatitis, hock burn, tibial dyschondroplasia, and metatarsal thickness were determined in the birds. Although the moisture content of the sludge was high, it decreased strongly after 7 d of drying, reaching lower values than those of wood shavings. In general, few differences were found between the materials in terms of bird performance and welfare and only the incidence of hock burn was higher in the sludge than in the wood shavings. Although further research is needed, sludge from paper recycling is a possible alternative to traditional bedding materials because it achieves most of the requirements for broiler bedding materials and does not show negative effects on the birds

Using APASS and 2GSS for studying variable stars

The AAVSO Photometric All-Sky Survey (APASS) provides calibrated magnitudes in the range 7 < V < 17 for the entire sky, in the BVugriZsY bandpasses. While primarily designed for 0.02 mag calibration, it provides photometry over a many-year baseline, and also has near daily cadence in the standard field regions on the equator. Likewise, the Second Generation Synoptic Survey (2GSS) is a follow-on to APASS, and will provide daily cadence in two passbands for the entire sky