Online modelling and state-of-charge estimation for lithium-titanate battery

Superior safety, is a promising energy storage element for electric vehicles. Its features can be fully utilised by using a fast charger and a high performance battery management system. Battery model is vital to a battery charger design for characterising the charging behaviours of a battery. Additionally, a robust state-ofcharge (SoC) estimation should be realised for a reliable battery management. This thesis develops a battery model for charger design and a robust method for SoC estimation by using MATLAB. The thesis proposed a transfer function-based battery model which is applicable for small-signal analysis and large-signal simulation of battery charger design, in order to capture the charging profiles of LTO battery. Busse’s adaptive rule, which has simple computations, is applied to improve the accuracy of Kalman filter-based SoC estimation. Busse’s adaptive Kalman filters are also applied for SoC estimation with online battery modelling to eliminate the complicated process of battery modelling. This study was conducted by using 2.4 V, 15 Ah LTO batteries. The batteries were tested with continuous current test and pulsed current test at several ambient temperatures (-25 ºC, 0 ºC, 25 ºC and 50 ºC) and charge/discharge currents (0.5 C, 1 C, 2 C). Additionally, modified dynamic stress tests at several temperatures (-15 ºC, 0 ºC, 15 ºC, 25 ºC, 35 ºC and 50 ºC) were also performed to test the battery under real EV environment. Results of the battery modelling showed that the developed transfer function-based battery model is accurate where the root-mean-square modelling error is less than 30 mV. The results also revealed that the Busse’s adaptive rule has effectively improved the Kalman filter-based SoC estimation for the case of offline battery model by giving a higher accuracy and shorter convergence time. Additionally, Busse’s adaptive Extended Kalman Filter gave a better accuracy in SoC estimation with online battery modelling. The proposed transfer function-based battery model provides a helpful solution for the battery charger design while the proposed Busse’s adaptive Kalman filter offers an accurate and robust SoC estimation for both offline and online battery models

Battery State-of-Charge Estimation with Extended Kalman-Filter using Third-Order Thevenin Model

Lithium-ion battery has become the mainstream energy storage element of the electric vehicle. One of the challenges in electric vehicle development is the state-of-charge estimation of battery. Accurate estimation of state-of-charge is vital to indicate the remaining capacity of the battery and it will eventually maximize the battery performance and ensures the safe operation of the battery. This paper studied on the application of extended Kalman-filter and third order Thevenin equivalent circuit model in state-of-charge estimation of lithium ferro phosphate battery. Random test and pulse discharge test are conducted to obtain the accurate battery model. The simulation and experimental results are compared to validate the proposed state-of-charge estimation method

Diphenylamine-substituted osmanaphthalyne complexes: structural, bonding, and redox properties of unusual donor–bridge–acceptor systems

Diarylamine-substituted osmanaphthalyne complexes that feature two redox centers linked by the rigid skeleton of the metallacycle (C^C+), specifically, [OsCl2(PPh3)2{(C^C+)NAr2}][BF4 ] (Ar=Ph (1 a), p-MeOPh (1 b)) and their open-ring precursors [OsHCl2(PPh3)2{(CC(PPh3 +)= CHPh)NR2}][BF4 ] (Ar=Ph (2 a), p-MeOPh (2 b)), were successfully synthesized and characterized by 1 H, 13C, and 31P NMR spectroscopy, ESI-MS, and elemental analysis. The solid-state molecular structures of complexes 1 a and 2 a were ascertained by single-crystal X-ray diffraction. The OsC bond length in both complexes 1 a and 2 a fell within the range reported for similar osmanaphthalynes and osmium carbyne complexes, respectively. The structural parameters determined for complex 1 a, which were successfully reproduced by theoretical calculations, point to a p-delocalized metallacycle structure. The purple color of compounds 1 a and b was explained by the diarylamine!Os(metallacycle) chargetransfer absorption in the visible region. The neutral, oneelectron-oxidized and one-electron-reduced states of compounds 1 a, b, and a reference complex that lacked the diarylamine substituent, [OsCl2(PPh3)2{(C^C+)}][BF4] (1’), were investigated by cyclic and square-wave voltammetry, UV/Vis/NIR spectroelectrochemistry, and DFT calculations. The spin density in singly oxidized complexes [1 a]+ and [1 b]+ predominantly resided on the aminyl segment, with osmium involvement controlled by the diphenylamine substitution. Spin density in stable, singly-reduced [1’] was distributed mainly over the osmanaphthalyne metallacycle

The littlest Higgs model with T-parity and single top production at epep collision

Based on calculating the contributions of the littlest Higgs model with T-parity (called $LHT$ model) to the anomalous top coupling $tq\gamma$ ($q=u$ or $c$), we consider single top production via the t-channel partonic process $eq\to et$ at $ep$ collision. Our numerical results show that the production cross section in the $LHT$ model can be significantly enhanced relative to that in the standard model.Comment: 11 pages, 5 figure

In situ phase transformation synthesis of unique Janus Ag2O/Ag2CO3 heterojunction photocatalyst with improved photocatalytic properties

Herein, Ag2O/Ag2CO3 nanocomposite with unique Janus morphology was synthesized by a facile ion-exchange followed by an in situ phase transformation method with precise control of its nucleation and growth processes. Contrary to conventional synthetic procedures of Janus architectures, the present Janus system was constructed without the need for surfactants or toxic chemicals. Most importantly, the visible-light-absorbing Janus Ag2O/Ag2CO3 nanocomposite exhibits a remarkable performance toward the degradation of Rhodamine B and 4-chlorophenol, far superior to that observed for bare Ag2CO3. The obvious enhancement of the photocatalytic performance of this nanocomposite is mainly attributed to the intimate Ag2O/Ag2CO3 interface created by its exceptional Janus architecture, which in turn allows for rapid charge transfer processes. Additionally, the Janus system exhibited a high photostability during recycling experiments with no significant change in the degradation activity

Performance of the CMS muon trigger system in proton-proton collisions at √s = 13 TeV

The muon trigger system of the CMS experiment uses a combination of hardware and software to identify events containing a muon. During Run 2 (covering 2015-2018) the LHC achieved instantaneous luminosities as high as 2 × 10 cm s while delivering proton-proton collisions at √s = 13 TeV. The challenge for the trigger system of the CMS experiment is to reduce the registered event rate from about 40 MHz to about 1 kHz. Significant improvements important for the success of the CMS physics program have been made to the muon trigger system via improved muon reconstruction and identification algorithms since the end of Run 1 and throughout the Run 2 data-taking period. The new algorithms maintain the acceptance of the muon triggers at the same or even lower rate throughout the data-taking period despite the increasing number of additional proton-proton interactions in each LHC bunch crossing. In this paper, the algorithms used in 2015 and 2016 and their improvements throughout 2017 and 2018 are described. Measurements of the CMS muon trigger performance for this data-taking period are presented, including efficiencies, transverse momentum resolution, trigger rates, and the purity of the selected muon sample. This paper focuses on the single- and double-muon triggers with the lowest sustainable transverse momentum thresholds used by CMS. The efficiency is measured in a transverse momentum range from 8 to several hundred GeV

Performance of the CMS muon trigger system in proton-proton collisions at √s = 13 TeV

The muon trigger system of the CMS experiment uses a combination of hardware and software to identify events containing a muon. During Run 2 (covering 2015–2018) the LHC achieved instantaneous luminosities as high as 2 × 10$^{34}$ while delivering proton-proton collisions at √(s) = 13. The challenge for the trigger system of the CMS experiment is to reduce the registered event rate from about 40MHz to about 1kHz. Significant improvements important for the success of the CMS physics program have been made to the muon trigger system via improved muon reconstruction and identification algorithms since the end of Run 1 and throughout the Run 2 data-taking period. The new algorithms maintain the acceptance of the muon triggers at the same or even lower rate throughout the data-taking period despite the increasing number of additional proton-proton interactions in each LHC bunch crossing. In this paper, the algorithms used in 2015 and 2016 and their improvements throughout 2017 and 2018 are described. Measurements of the CMS muon trigger performance for this data-taking period are presented, including efficiencies, transverse momentum resolution, trigger rates, and the purity of the selected muon sample. This paper focuses on the single- and double-muon triggers with the lowest sustainable transverse momentum thresholds used by CMS. The efficiency is measured in a transverse momentum range from 8 to several hundred