Ultracapacitor Research Articles

Economic, Technical and Environmental Aspects of Recycling Lithium Batteries: A Literature Review

In the last few years, the automotive industry has been moving towards fuel-free and economically sustainable alternatives, motivated by the latest trends in the market and new regulations about CO2 emissions. Hybrid and electric vehicles feature a transmission drive with one or more electrical motors powered by Lithium batteries. Thus, Lithium batteries are increasingly used in onboard energy storage systems, leading new economical, technical and environmental challenges which are of fundamental importance in this early stage for the next automotive generation. Recycling materials from used Lithium batteries can also moderate the price of virgin materials, by reducing the price disposal as well as the dependence of manufacturers on exporting countries. Furthermore, recycling Lithium-ion batteries has significant environmental benefits, such as containing the risk of chemical pollution and improving safety in storage facilities for exhausted batteries worldwide. This paper aims to provide a comprehensive insight on Lithium-ion battery recycling for scientific research and industrial applications, examining the economic, technical and environmental aspects of this topic.

Design and hardware investigation of a new configuration of an isolated DC-DC converter for fuel cell vehicle

The Electric vehicle supplied by the Polymer Electrolyte Membrane Fuel Cell is characterized by its efficiency as well as by lower air pollution in comparison with the classical vehicles. This paper will shed the light on the modelling and the realization of a DC/DC isolated converter connected to a fuel cell for electric hybrid vehicle. The input energy in the electrical vehicle is prod uced by two main independent power supplies, which are fuel cell and an ultra capacitor. An isolated unidirectional DC-DC converter, supplied by a fuel cell stack, is studied. The analytical models of the main source and the medium model presentation of the Isolated DC-DC converter are given. The Simulation results which were done under the Matlab-Simulink environment reveal that the proposed converter is effective and it is a better candidate for electrical vehicle application. The dynamic behaviours of the electrical vehicle drives are tested for a given driving cycle. The proposed DC-DC resonant converter has been realized and the control algorithm has been built using the dSPACE 1104 board.

Frequency Stabilization of Solar Thermal-Photovoltaic Hybrid Renewable Power Generation Using Energy Storage Devices

Isolated hybrid power systems (HPSs) with coordinated control of renewable energy sources (RESs) and energy storage devices (ESDs) with appropriate control techniques are studied in this paper for load frequency stabilization. The solar thermal power generation and photovoltaic systems are used as the primary source of generation in the designed test systems. The ESDs used are double-layer capacitor (DLC), ultra-capacitor (UC) and compressed air energy storage as per the designed test system to effectively supply insufficient energy of power generation in a short time. In the designed test system, it is assumed that UC transfers energy to the load side during adequate insolation. Whenever the same may not meet the load demand, DLC provides power to meet the remaining load demand. In one of the designed test systems, load frequency characteristics of the HPS model are carried out with high-voltage direct current link feeding to isolated load. The contribution of this work is the hybridization of RESs with ESDs with appropriate controller and applied control strategy. In the studied system, a proportional-integral-derivative controller is employed and its parameters are tuned by a nature-inspired moth flame optimization technique. The system dynamic performance with different operating conditions is carried out. Both the qualitative and the quantitative aspects show better performance of HPS models under study using the proposed technique.

Energy Management Optimization of Series Hybrid Electric Bus Using an Ultra-Capacitor and Novel Efficiency Improvement Factors

The existing series hybrid electric bus (SHEB) uses an ultra-capacitor (UC) to extend battery life, mitigate vehicle weight, and reduce cost. However, previous studies did not clearly identify the operation timing and load of the UC for efficiency improvement in an SHEB. This paper proposes novel efficiency improvement factors, with their application criteria for the ideal operation timing and load of the UC in an SHEB. The factors are the threshold of the required power of the motor (TRPM), slope of the power split ratio (SPSR), and y-axis intercept of the power split ratio (YPSR). The TRPM determines the duration of using just the battery. The SPSR or YPSR determine the most efficient load ratio between the battery and UC. The criteria for using them are set using particle swarm optimization. Manhattan, Braunschweig, and Orange County driving cycles were used to reflect various road load conditions. The results showed that the proposed factors and their setting criteria guarantee a significant reduction in the fuel consumption and more energy-efficient SHEBs.

Securing of an Industrial Soil Using Turfgrass Assisted by Biostimulants and Compost Amendment

This work aimed to study the effects of compost (applied at two rates) and two commercial microbial biostimulants on the mobility and bioavailability of potentially toxic elements (PTEs) in an industrial soil phytostabilized by Dactylis glomerata L. or a mixed stand of grasses (Lolium perenne L., Poa pratensis L. and Festuca arundinacea Shreb.). The soil showed very high pseudototal and bioavailable concentrations of cadmium (Cd) and lead (Pb), due to improper lead-acid batteries storage. Compost amendment in combination with the two biostimulants produced the best outcomes in terms of plant growth and nutrient uptake. The same mix of beneficial microbes improved soil biological fertility enhancing soil nitrogen fixing and ammonia oxidizing bacteria, while reduced the pore water and NH4NO3 extractable concentrations of Cd and at lower extent of Pb in soil. Accordingly, the lower mobility and bioavailability of Cd in soil determined a lower uptake and accumulation of Cd in shoots of different grass species. Our results suggest that a green cap with turfgrass assisted by biostimulants and compost amendment in PTE-contaminated industrial sites could be a reliable and effective practice to protect and restore soil biological fertility and to reduce the risk of PTE dispersion in the surrounding environment.

6 Pin IC Controlled Ultra Capacitor based Smart Street Light

6 Pin IC Controlled Ultra Capacitor based Smart Street Light

Design Considerations of Ultracapacitor Stack for Optimal Sizing of Energy Storage Systems in Contingency Applications

Ultracapacitors (UCs) today are playing an increasing role in the energy storage systems (ESSs) of several power conversion applications. In this article, a design method for optimal sizing of a UC stack is proposed, which minimizes the overall cost of the ESS. The problem is cast with normalized cost parameters of the ESS subsystem, using which the discharge ratio of the stack is optimized for the given ESS specifications. An iterative design algorithm is proposed which systematically engineers the stack parameters of unit cell capacitance, the number of series cells and parallel strings along with the initial and final stack voltage levels that meet the specified ESS requirements while also supplying the equivalent series resistance (ESR) loss. The iterative sizing process also factors in the maximum power transfer constraint imposed by the ESR to guarantee stable operation of the cost-optimal design even as the stack voltage varies during discharge. The design considerations, optimization framework, ESR effects, and the proposed sizing algorithm are synthesized in a generalized formulation in order to capture the variations in cost and subsystem parameter values that typically vary based on scaling requirements as well as the UC and power converter technology. Experimental results on a 4 kWmin UC stack validate the proposed cost-optimal design algorithm and the ESR induced voltage collapse.

Ultra Capacitor as a Source for Smart Street Light

Ultra Capacitor as a Source for Smart Street Light

Root-retained overdentures: Survival of abutment teeth with precision attachments on root caps depends on overdenture design.

Root-retained overdentures (OD) are one treatment option for partially edentulous patients. However, the available evidence regarding factors influencing abutment survival in root-retained ODs is limited. This retrospective study included clinical examinations and evaluated the survival rate of roots restored with precision attachments soldered to post-and-core (gold cap) retained ODs, analysed with respect to various patient- and prosthesis-related factors. Patients receiving at least one OD with gold caps in the past were invited for comprehensive clinical examinations. The primary outcome parameter was the abutment survival rate over the observation period (2002-2016). Possible contributing factors (eg closed vs open OD design) were analysed. Analyses included Kaplan-Meier estimators, Cox regressions and hazard ratios (HR). 114 patients with 128 ODs originally retained by 280 abutments, with a cumulative total exposure time of 2035.4years, were examined. Twenty-seven abutment teeth (9.6%) were lost after a mean observation period of 7.9±3.4years. Significant factors associated with abutment loss were a closed, compared to an open OD design (HR 8.38 (95% CI 1.11-63.59), P=.040), which was independent of the number of abutments per OD. Furthermore, the loss rate was higher when the denture was not worn day-and-night (HR 3.52 (95% CI 1.32-9.40), P=.012). Oral hygiene behaviour was associated with higher HRs. ODs remain a viable treatment option for patients with few teeth remaining in the dental arch. It is advisable to choose an open design for the OD, irrespective of the number of abutment teeth. Furthermore, gold cap-retained ODs should not be removed overnight.

An Integrated Energy Storage System With Voltage Balancing Based on Switched-Capacitor Reutilization Techniques

On account of complementary control, reduced size, and energy saving, the switched-capacitor (SC) based equalizer becomes promising for the energy management of energy storage system. Traditionally, the number of the bypass capacitor in the SC based equalizer equals to the number of the battery module in series or parallel connections. The amount of bypass capacitors is enormous, thus costly and bulky for electric vehicles (EVs). In this paper, the integrated energy storage is proposed to reduce cost and save space, meanwhile, the equalizations between the batteries and the ultracapacitors (UCs) are achieved by the reutilization of SC network. UCs not only perform as energy storage units, but also work as energy exchange units. Thus, the number of balanced elements can be reduced significantly. The operational principles of the storage system and the analyses of the balancing process are examined in detail. The system simulation is performed for functionality evaluations. Meanwhile, an experimental prototype is also implemented for six cells to demonstrate the balancing process. The accordance of experiment and simulation can further testify the feasibility and effectiveness.

Power consumption management under a low-level performance constraint in the Xen hypervisor

Virtualization is the main building block of many architectures and systems from embedded computing to large scale data-centers. Managing efficiently computing resources and their power consumption becomes fundamental to optimize the performance of the workloads running on those systems, however, hardware tools like Intel RAPL can only introduce power caps without considering performance. This paper presents a performance-aware power capping orchestrator for the Xen hypervisor. The tool exploits hybrid power management techniques to minimize power consumption respecting a given SLA, leveraging RAPL and overcoming its limitations. Experimental evaluation shows that the proposed approach guarantees good results for almost all the analyzed benchmarks (e.g. CPU-, memory- and IO-bound).

Performance analysis of distributed power flow controller with ultra-capacitor for regulating the frequency deviations in restructured power system

Abstract This paper presents a novel approach for automatic generation control (AGC) of two-area deregulated system with unequal sources for sustaining the frequency and tie-line power at perturbations. The combination of ultra-capacitor (UC) and various FACTS controllers such as Thyristor-controlled series capacitor (TCSC), Static synchronous series compensator (SSSC), Unified power flow controller (UPFC), and Distributed power flow controller (DPFC) have been investigated in AGC of interconnected system with thermal-wind and hydro-diesel generating units. An innovative metaheuristic method called bat algorithm (BA) is used to ascertain the optimal gain parameters of the two degree of freedom (2DOF) controllers using an integral squared error (ISE) criteria. Furthermore, the productive assessment of the bat tuned 2DOF controllers are also compared with teaching learning-based optimization (TLBO) and cuckoo search (CS) methods optimized 2DOF in distinct contract scenarios of the suggested restructured system. The effect of the coordinated performance of UC and DPFC has been mitigated the oscillatory response of the AGC system at various operating circumstances. The investigations disclose that the bat optimized 2DOF-PID yield the productive outcomes with coordination of DPFC and UC in all contract transactions of the restructured system.

Low Voltage Ride through of Grid Connected PMSG based Wind Energy Conversion System with Ultra Capacitor Storage System under Grid Fault Condition

Low Voltage Ride through of Grid Connected PMSG based Wind Energy Conversion System with Ultra Capacitor Storage System under Grid Fault Condition

ASSESSMENT OF BLOOD CHOLESTEROL AMONG STAFF IN KASHIM IBRAHIM COLLEGE OF EDUCATION MAIDUGURI, BORNO STATE, NIGERIA

<p>This study assessed of blood cholesterol among staff in Kashim Ibrahim College of Education Maiduguri, Borno state. Three hypotheses guided the study. Survey research design was used for this study. The population for the study comprised staff of Kashim Ibrahim College of Education Maiduguri numbering 566 (academic staff 216 and non-academic staff 350). A sample of 57 (males 37, females 20) staff were selected for the study using stratified sampling technique with proportionate method. The instruments used for data collection were floride oxalate container yellow cap and green cap, syringe (5ml) with needle to determine blood cholesterol of the participants; biodata sheet was used in recording the information of each participant. Analysis of data was done using descriptive statistics of mean, standard deviation, frequency counts and percentage. t-test and Analysis of Variance (ANOVA) was used to test hypotheses at 0.05 alpha level of significance. All the hypotheses formulated was retained. It was concluded that there is no significant difference in the hypotheses tested. Based on the results of this study, it was recommended that adequate sport facilities, including time allocation for sporting activities should be provided by the College authority within the College environment; that will enable the staff to participate in physical activities as a means of preventing the occurrence of these biomedical health risk factors.</p><p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/edu_01/0622/a.php" alt="Hit counter" /></p>

PowerCoord: Power capping coordination for multi-CPU/GPU servers using reinforcement learning

Modern supercomputers and cloud providers rely on server nodes that are equipped with multiple CPU sockets and general purpose GPUs (GPGPUs) to handle the high demand for intensive computations. These nodes consume much higher power than commodity servers, and integrating them with power capping systems used in modern clusters presents new challenges. In this paper, we propose a new power capping controller, PowerCoord, that is specifically designed for servers with multiple CPU and GPU sockets that are running multiple jobs at a time. PowerCoord coordinates among the various power domains (e.g., CPU sockets and GPUs) inside a node server to meet target power caps, while seeking to maximize throughput. Our approach also takes into consideration job deadlines and priorities. Because performance modeling for co-located jobs is error-prone, PowerCoord uses a learning method. PowerCoord has a number of heuristic policies to allocate power among the various CPUs and GPUs, and it uses reinforcement learning for policy selection during runtime. Based on the observed state of the system, PowerCoord shifts the distribution of selected policies. We implement our power cap controller on a real multi-CPU/GPU server with low overhead, and we demonstrate that it is able to meet target power caps while maximizing the throughput, and balancing other demands such as priorities and deadlines. Our results show PowerCoord improves the server throughput on average by 18% compared with the case when power is not coordinated among CPU/GPU domains. Also, PowerCoord improves the server throughput on average by 11% compared with prior work that uses a heuristic approach to coordinate the power among domains.

Realization of prototype hardware model with a novel control technique used in electric vehicle application

Battery and ultra-capacitor (UCp) combination forms the multiple energy storage model (MESM), which provides the optimum benefit to hybrid electric vehicles/electric vehicles (EVs) for its successful operation. The inherent high power density characteristic of UCp is used during starting and momentary periods of EV. On the other hand, the battery provides the average power to the EV, during the steady-state periods. The development of the supervisory energy management strategy, corresponding to the EV dynamics is one of the key issues. In this paper, a new control technique is proposed to attain a smooth and automatic transition between energy sources in MESM according to the EV requirement. A speed condition-based (SCB) controller is designed with four individual math functions, corresponding to the speed of the electric motor (EM). A combination of the SCB controller and the artificial neural network (ANN) formed a SCBANN hybrid controller (SCBANNHC). To identify the proper power split between energy sources, the proposed SCBANNHC is applied to the main circuit in four different case studies corresponding to the load on the EM. Four different case study circuit models are realized in the MATLAB/Simulink environment along with a prototype hardware model for validation of the proposed control technique.

On the Hybridization of Microcars with Hybrid UltraCapacitors and Li-Ion Batteries Storage Systems

The objective proposed by the EU to drastically reduce vehicular CO2 emission for the years up to 2030 requires an increase of propulsion systems’ efficiency, and accordingly, the improvement their technology. Hybrid electric vehicles could have a chance of achieving this, by recovering energy during braking phases, running in pure electric mode and allowing the internal combustion engine to operate under better efficiency conditions, while maintaining traditionally expected vehicle performances (mileage, weight, available on-board volume, etc.). The energy storage systems for hybrid electric vehicles (HEVs) have different requirements than those designed for Battery Electric Vehicles (BEVs); high specific power is normally the most critical issue. Using Li-ion Batteries (LiBs) in the designing of on-board Energy Storage Systems (ESS) based only on power specifications gives an ESS with an energy capacity which is sufficient for vehicle requirements. The highest specific power LiBs are therefore chosen among those technologically available. All this leads to an ESS design that is strongly stressed over time, because current output is very high and very rapidly varies, during both traction and regeneration phases. The resulting efficiency of the ESS is correspondingly lowered, and LiBs lifetime can be relevantly affected. Such a problem can be overcome by adopting hybrid storage systems, coupling LiBs and UltraCapacitors (UCs); by properly dimensioning and controlling the ESS’ components, in fact, the current output of the batteries can be reduced and smoothed, using UCs during transients. In this paper, a simulation model, calibrated and validated on an engine testbed, has been used to evaluate the performances of a hybrid storage HEV microcar under different operative conditions (driving cycles, environment temperature and ESS State of Charge). Results show that the hybridization of the powertrain may reduce fuel consumption by up to 27%, while LiBs lifetime may be more than doubled.

Energy Management on Battery/Ultracapacitor Hybrid Energy Storage System based on Adjustable Bandwidth Filter and Sliding-mode Control

Abstract A real-time power-split control strategy for a hybrid energy storage system (HESS) used in electric vehicles is proposed in this work. The HESS topology corresponds to a semi-active ultracapacitor (UC) configuration. The HESS goals are to prevent battery degradation and to preserve its lifetime while improving the system efficiency by supplying the fast dynamics power demands through the UC pack. In order to generate the UC power reference, a digital low-pass filter whose bandwidth is adjusted according to the UC SOC is proposed. This allows a better usage of the UC available energy, while reducing frequent activation of controller protections and avoiding the calculation of the filter cut-off frequency for a certain driving cycle. The low-level control strategy is based on a sliding mode controller combined with a closed-loop current observer, which allows to improve the implementation performance while maintaining the current ripple bounded. Simulation and experimental results were presented showing that the proposed strategy preserves battery health in a more effective way than filter-based strategies with fixed bandwidth, for cases where no future information about the required power is available.

Hydrogen Fuel Cell and Ultracapacitor Based Electric Power System Sliding Mode Control: Electric Vehicle Application

Control of a perturbed electric power system comprised of a hydrogen fuel cell (HFC), boost and boost/buck DC–DC power converters, and the ultra-capacitor (UC) is considered within an electric vehicle application. A relative degree approach was applied to control the servomotor speed, which is the main controllable load of the electric car. This control is achieved in the presence of the torque disturbances via directly controlling the armature voltage. The direct voltage control was accomplished by controlling the HFC voltage and the UC current in the presence of the model uncertainties. Controlling the HFC and UC current based on the power balance approach eliminated the non-minimum phase property of the DC–DC boost converter. Conventional first order sliding mode controllers (1-SMC) were employed to control the output voltage of the DC–DC boost power converter and the load current of the UC. The current in HFC and the servomotor speed were controlled by the adaptive-gain second order SMC (2-ASMC). The efficiency and robustness of the HFC/UC-based electric power systems controlled by 1-SMC and 2-ASMC were confirmed on a case study of electric car speed control via computer simulations.

Off‐board and on‐board energy storage versus reversible substations in DC railway traction systems

The present study describes and analyses a set of quasi-static railway power systems models and simulations considering on-board and off-board energy storage systems but also reversible and non-reversible substations and regenerative braking trains. The advantages and drawbacks of each technology are discussed. Then, several case studies considering different technological combinations are introduced and simulated, while the attained results are compared and analysed. In this regard, to cover all the casuistic, two simple explanatory cases are first exposed and then eight realistic scenarios are examined, which are simulated for a long time interval and also explained considering aggregated results.