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Choice of hybrid electric vehicles (HEVs) in transportation systems is becoming more prominent for optimized energy consumption. HEVs are attaining tremendous appreciation due to their eco-friendly performance and assistance in smart grid notion. The variation of energy storage systems in HEV (such as batteries, supercapacitors or ultracapacitors, fuel cells, and so on) with numerous control strategies create variation in HEV types. Therefore, choosing an appropriate control strategy for HEV applications becomes complicated. This paper reflects a comprehensive review of the imperative information of energy storage systems related to HEVs and procurable optimization topologies based on various control strategies and vehicle technologies. The research work classifies different control strategies considering four configurations: fuel cell-battery, battery-ultracapacitor, fuel cell-ultracapacitor, and battery-fuel cell- ultracapacitor. Relative analysis among different control techniques is carried out based on the control aspects and operating conditions to illustrate these techniques’ pros and cons. A parametric comparison and a cross-comparison are provided for different hybrid configurations to present a comparative study based on dynamic performance, battery lifetime, energy efficiency, fuel consumption, emission, robustness, and so on. The study also analyzes the experimental platform, the amelioration of driving cycles, mathematical models of each control technique to demonstrate the reliability in practical applications. The presented recapitulation is believed to be a reliable base for the researchers, policymakers, and influencers who continuously develop HEVs with energy-efficient control strategies.

The electrical energy storage system faces numerous obstacles as green energy usage rises. The demand for electric vehicles (EVs) is growing in tandem with the technological advance of EV range on a single charge. To tackle the low-range EV problem, an effective electrical energy storage device is necessary. Traditionally, electric vehicles have been powered by a single source of power, which is insufficient to handle the EV’s dynamic demand. As a result, a unique storage medium is necessary to meet the EV load characteristics of high-energy density and high-power density. This EV storage system is made up of two complementing sources: chemical batteries and ultracapacitors/supercapacitors. The benefits of using ultracapacitors in a hybrid energy storage system (HESS) to meet the low-power electric car dynamic load are explored in this study. In this paper, a HESS technique for regulating the active power of low-powered EV simulations was tested in a MATLAB/Simulink environment with various dynamic loading situations. The feature of this design, as noted from the simulation results, is that it efficiently regulates the DC link voltage of an EV with a hybrid source while putting minimal load stress on the battery, resulting in longer battery life, lower costs, and increased vehicle range.

The ever-growing penetration of Converter- Interfaced Distributed Renewable Energy Sources (CI-DRES) and the gradual decommission of synchronous generators (SGs) has posed several challenges related to the stability and robustness of the electric power systems. Since the main interface of the CI-DRES with the grid are the Voltage Source Converters (VSCs), there has been a major shift in the VSC control philosophy, where the absence of SGs is compensated by the Ancillary Services (ASs) provided by a new generation of CI-DRES. In order to make these ASs feasible and emulate the dynamic behaviour of a SG, the presence and advanced control of energy storage systems (ESS) together with the CI-DRES is essential, so that the CI-DRES/ESS has a dynamic behaviour similar to SG. In this paper, a new energy management control system is proposed for an ultracapacitor (UC) connected to the DC-bus of a CI-DRES. The aim is to control the DC bus voltage using the UC and, simultaneously, maintain the UC voltage within the limits while a given AS is provided. The control strategy is validated experimentally using a prototype with results revealing a reliable and stable operation.

Utilization of an ultracapacitor (UC)-based energy storage device can provide one of the most efficient solutions for short-term operational challenges in grid-connected photovoltaic (PV) systems. This paper proposes an algorithm for coordinated control of PV and ultracapacitor-based energy storage system to minimize the effects of sudden changes in solar irradiance and the presence of low voltages at the point of common coupling. In addition, this work proposes an improved multi-mode operational scheme for control of an ultracapacitor-based energy storage system that takes into consideration various associated limits during charging and discharging modes. The effectiveness of the proposed algorithm in mitigating the impacts of low voltages and short term changes in irradiance is demonstrated using simulation analysis carried out on the modified Consortium for Electric Reliability Technology Solutions (CERTS) microgrid testbed.

Global demand for energy is on a progressive increase and there is a need for environmentally friendly technologies to meet this demand. Electrochemical energy systems are hinged on clean and sustainable technologies. The latest trend in electrochemical energy systems is the supercapacitors (SCs). SCs are famous for their attractive properties: power density, charging time, life cycle, operational safety, and simplicity. However, their energy density is generally low and to a great extent, this parameter is invariably dependent on the nature of electrode material used. While high energy density is being sought for in SCs, it is necessary to keep abreast of recent electrode materials and their practical performances. This paper gives a concise description of capacitors with a focus on the non-Faradaic SCs. It also compendiously presents an overview of carbon electrode materials with their practical performances (specific surface area, specific capacitance, energy and power densities) for non-Faradaic SCs, with reference to more than 100 reputable works. Development and investigation of highly active carbon materials with optimized electrolytic compatibilities and manipulative morphologies and pore structures were recommended.

To overcome the failure of power electronic transformer in resisting input voltage interruption in power grid, a combination between energy storage link and PET(power electronic transformer) is utilized. The energy storage link consists of an ultracapacitors and a bidirectional DC/DC converter. When input voltage interruption occurs, PET with energy storage link can maintain PET′s low DC voltage to be stable. The main parameters of energy storage link are analyzed, the control strategy of the link is designed, and the simulation experiment is built in the MATLAB/Simulink. The simulation experiment results verify the ability of a diagram of PET with energy storage link can resist input voltage interruption in power grid, making the safe and stable operation of equipment in power grid.

The piezoelectricity allows the generation of electric power taking advantage of the movement of vehicles and pedestrians. Many prototypes have been made with piezoelectric generators, but at present, their commercialization and use have not been popularized due to their low power generation and energy losses. A design of an experimental prototype of an energy harvester with piezoelectric materials that reduces these losses and generates more energy thanks to the resonance with the beams is proposed in this article. An equilateral triangular tile is designed such it will not deform when a force acts on it. The tile has four-cantilever beams, and it is designed to resonate with the natural frequency of the piezoelectric material. This is coupled to the piezoelectric device. The vibration generated on the beam, by a mechanical load, is used to generate more energy when it resonates. The piezoelectric is a ceramic material and generates a nominal power of 75 mW before placing it on the beam, and 375 mW after being placed on the beam. However, the energy collection circuit has losses due to its own consumption, the transmission of energy to the storage system, and in the mechanical system. RESUMEN La piezoelectricidad permite la generación de energía eléctrica aprovechando el movimiento de vehículos y peatones. Se han realizado muchos prototipos con generadores piezoeléctricos, pero en la actualidad no se ha popularizado su comercialización y utilización. Se presenta en este artículo un diseño de un prototipo experimental de un cosechador de energía con materiales piezoeléctricos. Con el aprovechamiento de la energía peatonal se realiza el diseño de una baldosa para la implementación en espacios interiores. En esta propuesta se realizó el diseño previo de la baldosa que es de tipo triangular equilátera, para que no se deforme cuando actúe una fuerza sobre ella. Está conformado por un sistema de cuatro vigas en voladizo, diseñadas con el objetivo de que entren en resonancia y se pueda aumentar la energía obtenida del material piezoeléctrico. La vibración generada sobre la viga, por medio de una carga mecánica es aprovechada para generar energía. Los piezoeléctricos son de material cerámico. Antes de colocarlo en la viga, se generó 75 mW nominales, y con la viga generó una potencia de 375 mW. Sin embargo, el circuito de recolección de la energía tiene pérdidas debido a su propio consumo, a la transmisión de la energía al sistema de almacenamiento y en el sistema mecánico.

Numerously different porous carbons have been prepared and used in a wide range of practical applications. Porous carbons are also ideal electrode materials for efficient energy storage devices due to their large surface areas, capacious pore spaces, and superior chemical stability compared to other porous materials. Not only the electrical double-layer capacitance (EDLC)-based charge storage but also the pseudocapacitance driven by various dopants in the carbon matrix plays a significant role in enhancing the electrochemical supercapacitive performance of porous carbons. Since the electrochemical capacitive activities are primarily based on EDLC and further enhanced by pseudocapacitance, high-surface carbons are desirable for these applications. The porosity of carbons plays a crucial role in enhancing the performance as well. We have recently witnessed that metal–organic frameworks (MOFs) could be very effective self-sacrificing templates, or precursors, for new high-surface carbons for supercapacitors, or ultracapacitors. Many MOFs can be self-sacrificing precursors for carbonaceous porous materials in a simple yet effective direct carbonization to produce porous carbons. The constituent metal ions can be either completely removed during the carbonization or transformed into valuable redox-active centers for additional faradaic reactions to enhance the electrochemical performance of carbon electrodes. Some heteroatoms of the bridging ligands and solvate molecules can be easily incorporated into carbon matrices to generate heteroatom-doped carbons with pseudocapacitive behavior and good surface wettability. We categorized these MOF-derived porous carbons into three main types: (i) pure and heteroatom-doped carbons, (ii) metallic nanoparticle-containing carbons, and (iii) carbon-based composites with other carbon-based materials or redox-active metal species. Based on these cases summarized in this review, new MOF-derived porous carbons with much enhanced capacitive performance and stability will be envisioned.

This paper introduces a modular testbed to simulate AC/DC microgrids. The testbed is implemented in Matlab Simulink and is based on the energetic macroscopic representation (EMR) formalism. It is designed to be a tool to evaluate energy management strategies in AC/DC microgrids. The microgrid simulation model includes a photovoltaic generator, a fuel cell system, ultracapacitors, and batteries on the DC side. It includes voltage source converters (VSC) to couple the DC side with the AC side of the microgrid, which includes a variable AC load and a synchronous generator. Two case studies illustrate the use of the testbed. The model is implemented in Matlab Simulink and made openly available for the scientific community. Using this model, researchers can develop and evaluate energy management strategies in AC/DC microgrids.

As energy storage device of hybrid electric vehicles (HEVs), ultracapacitors feature the advantages of higher power density and longer life cycle compared with batteries. However, when ultracapacitors of the same power level are used instead of batteries, fuel consumption becomes more sensitive to changes in control parameters as ultracapacitors store much less energy, and the state of charge (SOC) is power-sensitive. In this paper, optimization of control parameters for a power-split HEV with ultracapacitors is addressed to achieve better fuel economy. First, a power-split HEV model and a corresponding control strategy are established under the MATLAB script environment for convenient analysis and application of an optimization algorithm. Second, focusing on the power-sensitive characteristic of the SOC, three key control parameters are determined, and their effects on fuel consumption are analyzed. Third, an improved particle swarm optimization (IPSO) algorithm is proposed to overcome the disadvantage of the PSO trapping into “local optimum” and improve optimization efficiency. To fully exploit the fuel-saving capability of the HEV, driving cycle segmentation is also considered. The IPSO is used to optimize three key control parameters under the segmented adapted world transient vehicle cycle. Finally, the optimal results are applied to hardware-in-the-loop test to verify the effectiveness of the proposed optimization method. Compared with the fuel consumption before optimization, the fuel saving rate reaches 9.20% in the urban section, 6.40% in the roadway section, and 5.40% in freeway section.

A novel dynamic average-value model (AVM) of energy storage systems (ESS) integration in power grid for long-term control is developed and validated. It is expected to greatly improve the computational speed of power system dynamics in a long-term simulation. To end this, the development of the dynamic AVM of ESS integration including ultracapacitor, DC–DC converter, and voltage source converter is elaborated upon. A new control strategy which uses digital logic circuit is proposed to keep the ultracapacitors from overcharging without significantly increasing the charging time. To validate the proposed dynamic AVM and control strategy, case studies are carried out to perform the dynamics as affected by sudden changing of charging/discharging of ESS. The accuracy of the proposed model and controller is verified by the simulation results with that obtained from the detailed model implemented in MATLAB/Simulink. Moreover, the time-step size is enlarged greatly without sacrificing the accuracy, therefore the computational speed is improved significantly.

A new generation high field spherical tokamak, ST40, is currently under construction at Tokamak Energy Ltd (TE). The main parameters of ST40 are: R 0 = 0.4–0.6 m, A = 1.7–2.0, I pl = 2 MA, B t = 3 T, κ = 2.5. It will have power supplies based on ultracapacitors, liquid nitrogen-cooled copper magnets, up to 2 MW of neutral beam injected (NBI) power, and a pulse length of ∼3 s when operating at full power. To stabilize the highly elongated plasma, in addition to active vertical control, liquid nitrogen-cooled passive plates will be installed. ST40 is aimed at demonstrating burning plasma condition parameters ( nTτ E ) and may also be suitable for DT operations in future. The main physics and engineering challenges are caused by the high toroidal field, relatively high plasma current, and wall and divertor power loads.

The use of electric vehicles and their various configurations is seen as a major alternative in efforts towards reducing pollutant emissions from motor vehicles that continue to use fossil fuels. Electric transport technology presents more efficient means of energy conversion in vehicles: electric (EV), hybrid (VH), and hybrid electric (HEV) vehicles. For example, the energy storage system in the latter can be made up of ultracapacitors (UCs), batteries (Bs), and fuel cells. This work focuses on HEVs powered by batteries and ultracapacitors. In particular, the multiple converter configuration (C-CM) for the HEV powertrain system is analyzed using electric models of the vehicle powertrain components. To analyze the multiple converter configuration, parameters of a vehicle taken from the literature and the electrical model of the configuration were developed. With the above, the proposed configuration was evaluated before driving cycles (CITY II and ECE) and the configuration performance was compared with respect to other configurations. In the C-CM model, limitations in the choice of the number of Bs and UCs were observed in the powertrain depending on the maximum power of both energy sources and vehicle load demand. The results show that more energy is extracted from the batteries in the ECE cycle than in the CITY taking into account that the batteries are used as the main power source. C-CM results compared to other configurations show that energy extracted from batteries in the CITY is the same across all configurations. While energy consumption is lower in the ECE, C-CM results were not very significant compared to other configurations. However, the C-MC has the advantage of having better power flow control due to having two converters, thus improving HEV safety.

The rapid progress in the fields of energy storage and power electronics offers various promising improvements of conventional powertrain architectures. This thesis investigates the improvement potential of Hybrid Energy Storage Systems (HESSs) and Gallium Nitride (GaN) semiconductors in the powertrain of an electric racing motorcycle, designed for the MotoStudent competition. To ascertain the state of the art, the powertrain architectures of several commercial electric motorcycles and racing prototypes are compared. Subsequently, the powertrain of the current prototype, developed at the University of Oviedo, is explained in detail and the performance is analytically assessed. As first potential improvement, HESSs made of Lithium-Ion (Li-ion) batteries and Ultracapacitors (UCs) are evaluated. An optimization algorithm for the design of the HESS, which considers two semi-active topologies, is introduced. Further analysis juxtaposes the optimization results with pure Li-ion battery storage in terms of weight and volume. In the case of the MotoStudent load profi le, results in favor of pure battery storage are presented. Thereupon, the feasibility of a 500 ARMS GaN traction inverter is analyzed. For this purpose, an electrical and thermal co-simulation is performed in PLECS. In order to accurately model the semiconductor losses, 3D lookup tables are utilized. Based on the results, a minimum number of sixteen parallel devices is determined to meet the requirements. As such high numbers of parallel devices have not been studied in literature yet, a double-pulse test Printed Circuit Board (PCB) is designed to evaluate the feasibility. The measurements carried out demonstrate the full functionality of the design and successful parallelization of sixteen GaN transistors.

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.

Inertia plays a vital role in maintaining the frequency stability of power systems. However, the increase of power electronics-based renewable generation can dramatically reduce the inertia levels of modern power systems. This issue has already challenged the control and stability of small-scale power systems. It will soon be faced by larger power systems as the trend of large-scale renewable integration continues. In view of the urgent demand for addressing the inertia concern, this paper presents a comprehensive review of inertia enhancement methods covering both proven techniques and emerging ones and also studies the effect of inertia on frequency control. Among those proven techniques, the inertia emulation by wind turbines has successfully demonstrated its effectiveness and will receive widespread adoptions. For the emerging techniques, the virtual inertia generated by the dc-link capacitors of power converters has a great potential due to its low cost. The same concept of inertia emulation can also be applied to ultracapacitors. In addition, batteries will serve as an alternative inertia supplier, and the relevant technical challenges as well as the solutions are discussed in this paper. In future power systems where most of the generators and loads are connected via power electronics, virtual synchronous machines will gradually take over the responsibility of inertia support. In general, it is concluded that advances in semiconductors and control promise to make power electronics an enabling technology for inertia control in future power systems.

International audience; Compared to Li-ion batteries, supercapacitors (SCs) boast longer lifespan, higher power density, and wider operational temperature range. Nevertheless, SCs are expensive (almost 40 times more expensive per watthour than Li-ion batteries). SCs aging is critical. Two types of aging tests are usually performed. Floating aging tests apply constant constraints (voltage and temperature), and cycling aging tests apply multiple charges and discharges. We focus our study on floating aging [corresponding for instance to parking mode for electrical vehicles (95% of the time) or uninterruptible power supplies (UPSs) when they are not solicited (quite all the time)]. All results in the literature conclude that voltage level is an acceleration factor for SC aging. According to the literature, it would be interesting to totally discharge the SCs when they are not in active use (i.e., when the UPSs or vehicles are turned off) to improve their lifespan. Contrary to the literature forecasts (i.e., lower voltage increases lifespan of SC), the results obtained in this paper by alternating voltage resets (0 V, 60 °C) and floating aging (2.8 V, 60 °C) show that discharging even very few times the SCs shortens their lifespan drastically. Physical interpretations are presented to explain aging increase with voltage resets.

Con el propósito de dar continuidad a un proyecto de investigación de carácter interdisciplinar en el cual se busca ofrecer una alternativa de vehículos eléctricos autónomos apropiados para la topografía del país, mediante el diseño de un vehículo eléctrico de ato desempeño y alta densidad de potencia, se presenta la investigación y el diseño de un convertidor DC/DC de potencia y alta eficiencia el cual es el elemento más importante dentro del sistema eléctrico del vehículo. La presente investigación tiene como objetivo de diseño minimizar las pérdidas del convertidor y obtener la mejor relación posible en términos de eficiencia y volumen dados los parámetros iniciales dispuestos en el trabajo previo. Por tal motivo partiendo de una topología previamente seleccionada, el “DC/DC Boost Interleaved Converter” se hace un análisis y diseño de distintas variaciones a esta topología con el objetivo de optimizar el diseño. Adicionalmente se realizó el diseño de una nueva topología de núcleo magnético, el cual integra cuatro fases, permitiendo lograr una adecuada distribución de flujo magnético por el mismo y su utilización en convertidores intercalados. Finalmente, sobre la topología optimizada se realiza una caracterización y comparación de cada uno de los elementos con el fin de encontrar la mejor relación que represente las menores pérdidas. Se logró obtener, bajo el análisis realizado, un diseño de una nueva topología que mediante los resultados obtenidos ofrece la mejor respuesta en términos de eficiencia y relación de volumen para ser implementada en vehículos eléctricos. Adicionalmente se logró diseñar y obtener la configuración de la topología del convertidor DC-DC intercalado para aplicación específica a esta investigación de manera que pueda ser implementado, a partir de los elementos que se pueden conseguir actualmente en el comercio. Abstract: With the purpose of giving continuity to an interdisciplinary research project in which it is sought to offer an alternative of autonomous electric vehicles for the topography of the country, through the design of an electric vehicle of high performance and power density, it is presented the research and design of a DC / DC power converter of high efficiency which is the most important element in the vehicle's electrical system. The objective of this research is to minimize the efficiency and volume of the converter. Starting from a defined topology, the DC/DC Boost Interleaved Converter, it is made an analysis and design of different variants for this topology in order to optimize the design. Additionally, the design of a new magnetic core topology was carried out, which integrates four phases, allowing an adequate distribution of magnetic flux through it and its use in interleaved converters. Finally, a characterization and comparison of each element of the optimized topology is carried out in order to find the best relationship that represents the lower losses. It was possible to obtain, under the carried out analysis, a design of a new topology that, with the obtained results, offers the best response in terms of efficiency and volume ratio for being implemented in electric vehicles. In addition, the achieved design of the DC-DC converter can be implemented using elements that can be commercially obtained. Maestría

Inertia plays an essential role in maintaining the frequency stability of power systems. Nevertheless, the increase of power electronics-based renewable generation can dramatically reduce the inertia of modern power systems. This issue has already challenged the control and stability of small-scale power systems. It will soon be faced by larger power systems as the trend of renewable integration continues. In view of the inertia challenge, this paper presents a comprehensive review of conventional and emerging inertia enhancement techniques. It is revealed that the inertia emulation by wind turbines has successfully demonstrated its effectiveness and will receive widespread adoptions. In addition, the virtual inertia generated by the DC-link capacitors of power converters has a great potential due to its low cost. The same concept can also be applied to ultracapacitors. Moreover, batteries will serve as an alternative inertia supplier. In future power systems where most of the generators and loads are connected via power electronics, virtual synchronous machines (VSMs) will become the main inertia provider. In general, it is concluded that advances in semiconductors and control promise to make power electronics an enabling technology for inertia control in future power systems.

This contribution outlines the design of electric vehicle direct-current (DC) bus control system supplied by a battery/ultracapacitor hybrid energy storage system, and its coordination with the fully electrified vehicle driveline control system. The control strategy features an upper-level DC bus voltage feedback controller and a direct load compensator for stiff tracking of variable (speed-dependent) voltage target. The inner control level, comprising dedicated battery and ultracapacitor current controllers, is commanded by an intermediate-level control scheme which dynamically distributes the upper-level current command between the ultracapacitor and the battery energy storage systems. The feedback control system is designed and analytical expressions for feedback controller parameters are obtained by using the damping optimum criterion. The proposed methodology is verified by means of simulations and experimentally for different realistic operating regimes, including electric vehicle DC bus load step change, hybrid energy storage system charging/discharging, and electric vehicle driveline subject to New European Driving Cycle (NEDC), Urban Driving Dynamometer Schedule (UDDS), New York Certification Cycle (NYCC) and California Unified Cycle (LA92), as well as for abrupt acceleration/deceleration regimes.

This article analysis the bidirectional operation of the so called Isolated Efficient Wide Range Converter (I-EWiRaC), equipped with synchronous rectification, including small signal modelling and controller design. The converter is used in fuel-cell-based back-up systems, with ultra capacitors (UC) as intermediated energy storage between the fuel cell and the power converter. Earlier, an additional converter was used to charge the UC to the required DC voltage. The presented idea can improving the system efficiency and reliability and reduce overall system costs.

International audience; The global need to solve pollution problems has conducted automotive engineers to promote the development and the use of electric vehicle technologies. This paper focuses on the fuel cell hybrid electric vehicle which uses a proton exchange membrane fuel cell as a main source associated to hybrid storage device: lithium ion battery and ultracapacitors. A common interest in such technology is to spread out the energy flow between its different sources in order to satisfy the power demand for any requested mission. However, the challenging task stills the optimization of this split to reduce hydrogen consumption and respect, at the same time, the system limitations such as admissible limits of storage system capacities and battery current variation. An adaptive filtering-based energy management strategy is proposed in this paper to ensure an optimum distribution of the energy between the sources taking into account dynamic and energetic constraints of each device. For more performance, a fuzzy logic system is used to adapt the frequency of separation with the system state evolution. A sliding mode control is applied to control electric characteristics (voltage and currents) in the considered hybrid power supply. Simulation results, obtained under MATLAB®/SimPowerSystems® for four driving cycles are presented. The proposed strategy achieved good performances by respecting the ultracapacitors state of charge while preserving the battery lifetime under various driving missions.

The on-board energy-storage system of an electric vehicle (EV) should be able to collect large amounts of energy and to deal with fast load variations. The use of hybrid power sources as storage devices is an attractive solution, aiming at maximizing both energy and power density. The battery/ultracapacitors (UCs) combination promises to provide significant benefits. An accurate design of bi-directional converters, capable of proplery managing the charge/discharge of the UCs from/to a voltage bus, is essential. In this paper, a bi-directional DC-DC converter connected to a bank of UCs is described and the simulation results are given as well. The designed converter is a buck-boost type, able to manage a 40kW peak power for a duration of 3s, required by a 48 V bus-connected load.

This work carries out a comparison of non-isolated topologies for power electronic converters applied to Hybrid Energy Storage Systems. At the considered application, several options for three-port circuits are evaluated when interfacing a DC link with two distinct electrical energy storage units. This work demonstrates how the proposed structure, referred to as Series-Parallel Connection, performs as a simple, compact and reliable approach, based on a modification of the H-bridge configuration. The main advantage of this solution is that an effective large voltage gain at one of the ports is attained by means of a simple topology, preventing the use of multilevel or galvanic-isolated power stages. The resulting structure is thoroughly compared against the most significant direct alternatives. The analysis carried out on the switching and conduction losses in the power switches of the target solution states the design constraints at which this solution shows a performance improvement. The experimental validations carried out on a 10 kW prototype demonstrate the feasibility of the proposed scheme, stating its benefits as well as its main limitations. As a conclusion, the Series-Parallel Connection shows a better performance in terms of efficiency, reliability and controllability in the target application of compensating grid or load variations in Non-Isolated Hybrid Storage Systems, with large mismatch in the storage device voltage ratings.

In this paper, we propose the use of the electrochemical impedance spectroscopy technique for state diagnosis of electric double-layer ultracapacitors. Ultracapacitors under investigation are Maxwell BCAP 0350 and they were stressed in several ways for our study. The analyzed stress conditions include accelerated aging tests, overvoltage, and over temperature tests. Chemical and physical effects on supercapacitor materials are pointed out through a morphologic analysis implemented by means of an environmental scanning electron microscope and a chemical composition analysis obtained by means of an energy dispersive spectrometer. Consequent degradation effects are described in terms of frequency behavior of equivalent circuital parameters.

International audience; In this paper, the control and energy management strategy are proposed for an electric vehicle (EV) application. The hybrid source is composed of Fuel Cell (FC) and Ultracapacitors (UCs). The proposed energy management is used to share the EV energy requirement between the hybrid energy source, where the UCs are connected to DC-bus through a bidirectional DC/DC converter, and the FC is linked to the DC-bus through unidirectional DC/DC converter. The main purpose of this paper is focused on EV requested power sharing in real time operations between the FC stack and the UCs according to the electrical characteristics of these sources using polynomial correctors. In this study, only the traction operation mode is considered. The validity of the control is proofed through reduced scale experimental tests.

International audience; This paper presents energy management strategy for electric vehicle (EV) applications. The proposed method is used to share the requested energy of the EV between the ultracapacitors (UCs) and lithium-batteries. The traction motor is a Permanent Magnet Synchronous Machine (PMSM) controlled by a Voltage-Source-Inverter (VSI) and fed by the UCs and the batteries. The energy storage system (ESS) is connected to DC-bus through two DC-DC converters. The aim of this paper is focused on requested EV power sharing between UCs pack and the batteries pack according to the dynamic response of these sources using anti-windup PI controller. This study is based on a real example of EV, in addition only the traction mode is considered. The performances of the proposed method are evaluated through some simulations using MATALB/Simulink software.

Ultracapacitors (UCs), with their features of high power density and high current charge-discharge, have become the best choice for dynamic power compensation to improve the stability of microgrids and are increasingly being applied in microgrids. This paper presents the control of an energy storage system (ESS) based on ultracapacitors in the context of grid-connected microgrids. The ESS is composed of DC/AC and DC/DC converters tied by a dc link. An improved dynamic model for the ESS is proposed. Based on the proposed model a Proportional-Integral-Resonant (PIR) DC link voltage controller is proposed to maintain the DC link voltage through the charging-discharging control of ultracapacitors, capable of working properly under all operating conditions. An extra double frequency component is injected into the UC current by a R controller to dynamically compensate for DC instantaneous power and double frequency AC instantaneous power due to unbalanced grid conditions and disturbances. This feature maintains the DC link voltage constant under unbalanced conditions and increases the degrees of freedom of the DC/AC converter and thus facilitates the application of UCs in microgrids. Simulation and experimental results verify the effectiveness of the proposed control strategy.

Symmetric ultracapacitors have been fabricated considering nanometric 3-layered films made of alternated layers of poly(3,4-ethylenedioxythiophene) (external and internal layers) and polypyrrole (intermediate layer) deposited on steel uncoated and coated with octanethiol self-assembled monolayer. The highest electrochemical and capacitance parameters (i.e. electroactivity, doping level, stored charge, specific capacitance, Coulomb efficiency, energy density and power density) correspond to the ultracapacitor derived from the assembly of 3-layered films deposited on pre-treated steel. Thus, the interface separating the octanethiol monolayer and the most internal layer of the 3-layered film produces a very favorable interaction, which promotes important electrochemical benefits similar to those found for the interfaces in conventional multilayered films. Moreover, the pre-treatment of the steel electrode enhances the roughness and porosity of the film deposited on it, transmitting this effect layer-by-layer. Structural and morphological characteristics, which have been characterized using scanning electron microscopy and atomic force microscopy, have been related with the electrochemical and capacitance properties of the ultracapacitors.

Carbon nanotube/metal oxide based hybrids are envisioned as high performance electrochemical energy storage electrodes since these systems can provide improved performances utilizing an electric double layer coupled with fast faradaic pseudocapacitive charge storage mechanisms. In this work, we show that high performance supercapacitor electrodes with a specific capacitance of ∼192 F/g along with a maximum energy density of ∼3.8 W h/kg and a power density of ∼28 kW/kg can be achieved by synthesizing zinc oxide nanowires (ZnO NWs) directly on top of aligned multi-walled carbon nanotubes (MWCNTs). In comparison to pristine MWCNTs, these constitute a 12-fold of increase in specific capacitance as well as corresponding power and energy density values. These electrodes also possess high cycling stability and were able to retain ∼99% of their specific capacitance value over 2000 charging discharging cycles. These findings indicate potential use of a MWCNT/ZnO NW hybrid material for future electrochemical energy storage applications.

U ovom radu je dan kratak pregled pasivnih, poluaktivnih i aktivnih topologija mikromreža. Nakon toga su opisani postupci upravljanja jednostrukim (polu-aktivna topologija) a zatim i višestrukim energetskim pretvaračima (aktivna toplogija). Projektiran je sustav regulacije struje pojedinih spremnika energije, ultrakondenzatora i baterije primjenom kriterija optimuma dvostrukog odnosa. Nakon toga je projektiran sustav regulacije izlaznog napona DC sabirnice za jedan energetski pretvarač. Zatim je primjenjena droop regulacija na jednom energetskom pretvaraču kondicioniranjem reference napona dodatnom povratnom vezom po struji i virtualnim otporom . Kako bi se sprijećila stacionarna odstupanja kod droop regulacije implementiran je nadređeni I regulator. Nakon projektiranja regulatora s jednim spremnikom energije projektirani su regulatori aktivne topologije i droop upravljanja s dva spreminka energije. Zatim je dan pregled u osnovne vrste energetskih pretvarača zajedno s opisom njihova rada. U sklopu ovog diplomskog rada projektirana je eksperimentalna maketa na kojoj je moguće testirati razne tehnike upravljanja mikromrežama, također objašnjen je programski kod za implemtaciju na mikrokontroleru u programskom jeziku C prethodno opisanih tehnika upravljanja. This paper presents a brief overview of passive, semi-active and active microgrid topologies. Subsequently, a power converter DC link output voltage control system has been designed along with inner current control loops of batteries and ultracapacitors that are set by the damping optimum criterion application. Then, droop regulation was applied to one power converter by conditioning the voltage reference with an additional DC and DC resistance feedback. After designing a single energy tank controller, active topology regulators and a two-state power management droop have been designed. As part of practical work, an experimental model was carefully designed and made as well as a program code for implementation previously described regulation techniques on the microcontroller in the programming language C. Experimental model or DC/DC power converter with three independently controlled legs (power converters) provides users various simulation scenarios to be tested. Some of the regulation techniques have been tested on the experimental model, the results are also presented in this paper.

Glavna značajka akumulatorskih baterija je mogućnost pohrane velikih količina energije i zato su s vremenom postale glavni izvor napajanja kod većine prenosivih uređđaja. Suprotno baterijama, superkondenzatori imaju veliku gustoću snage, ali malu gustoću energije. U ovom radu osmišljeno je i projektirano rješenje hibridnog superkondenzatorsko-baterijskog spremnika za izravno skladištenje energije koje bi iskorištavao najbolja svojstva superkondenzatora i baterija. Detaljno je razrađen i objašnjen način rada jednog takvog sustava. Predstavljeni su modeli punjenja i praţnjenja akumulatorskih litij-ionskih baterija i superkondenzatora. Također, razvijeni su elektronički podsustavi koji štite elemente sustava od nedozvoljenih razina struja i napona. Zbog pretpostavke o zagrijavanju pojedinih elektroničkih komponenti projektirani sklop termički je analiziran. Korištenjem programskog okruženja Altium Designer nacrtana je elektronička shema sustava, sastavljen je popis materijala i projektirana tiskana pločica povezuje mikrokontroler i sve komponente međusobno u jednu povezanu cjelinu. The main feature of accumulator batteries is the ability to store large amounts of energy and therefore they have become the main source of power for most portable devices over time. Contrary to batteries, ultracapacitors have a high density of power, but low energy density. In this bachelor thesis a hybrid ultracapacitor-battery storage that exploits best characteristic ultracapacitors and batteries was designed. There is a detailed elaboration and explanation of how one of these systems should work. The charging and discharging models of lithium-ion batteries and ultracapacitors are featured. Also, electronic subsystems that protect system elements from unauthorized levels of current and voltage were designed. Due to the assumption of heating of individual electronic components the designed circuit is thermally analyzed. Using the Altium Designer programming environment, an electronic scheme of system was drawn up, a list of materials was made and the printed circuit board that connects the microcontroller and all components to one another in a single entity was designed.

Energy storages take a key role in electrical energy balancing in our power grid in respect to the increasing utilization of renewable energies. Assessing the effectiveness of energy storages and finding the optimal use under varying load conditions is essential which requires accurate modelling. This study highlights the equivalent circuit modelling approach for different energy storages. The model parameters R, L, C and Ub define the storage system in question allowing us to analyse storage devices under varying load conditions. Technical assessment criteria (efficiency, response time etc.) of energy storages can also be deducted from these models. Energy storages feature non-linear characteristics which are reflected in variable model parameters. QC 20170821

With the purpose of designing the electric powertrain of a high performance electric vehicle capable of running a quarter mile in 10 seconds, firstly it is necessary to calculate the required energy, torque, and power in order to size and select the suitable storage components and electric motors. Secondly, an assessment of the powertrain arrangement is needed to choose the best internal configuration of the vehicle and guarantee the highest efficiency possible. Finally, a design of the power conversion stages, specifically the DC-DC converter that interfaces the storage unit with the electric motors, is required as well. This paper shows the energy calculation procedure based on a longitudinal dynamic model of the vehicle and the selection method of the storage components and motors needed for this application, as well as the design of two 100 kW interleaved boost converters with coupled inductors. In addition, a novel operation of the interleaved boost converter is proposed in order to increase the efficiency of the converter. As a result, the designed converter achieved a power density of 24,2 kW/kg with an efficiency of 98 %, which was validated by experimental tests of a low power prototype. Para diseñar el tren de potencia de un vehículo eléctrico de alto desempeño capaz de correr un cuarto de milla en 10 segundos, primero es necesario calcular la potencia y energia necesarias para dimensionar y seleccionar los componentes de almacenamiento y los motores adecuados. Segundo, se requiere una evaluación de varios trenes de potencia para seleccionar la mejor configuración interna del vehículo con el propósito de garantizar la mayor eficiencia posible. Finalmente, se necesita un diseño del convertidor de potencia DC-DC que haga la interfaz entre la unidad de almacenamiento y los motores eléctricos con sus respectivos inversores. Este artículo presenta el procedimiento para el cálculo de la energia necesaria para correr el vehículo con base en un modelo dinámico longitudinal. Así mismo, se presenta el método de selección de los componentes de almacenamiento de energía necesarios. Finalmente, se presenta el diseño de dos convertidores intercalados con inductores acoplados de 100 kW operando bajo una novedosa operación propuesta para incrementar la eficiencia del convertidor. Como resultado, el convertidor diseñado logró una densidad de potencia de 24,2 kW/kg y una eficiencia de 98 %, la cual es validada con pruebas experimentales de un prototipo de baja potencia.

IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society, Florence, ITALIE, 23-/10/2016 - 26/10/2016; This article proposes an energy recuperation management of a Hybrid Energy Storage System (HESS) during regenerative braking of an Electric Vehicle. The HESS is composed of a Li-Ion battery, and a high speed Flywheel Energy Storage (FES). At low speed, the integration of a controlled dissipative resistor is used to prevent battery overcurrent and overvoltage. At high speed, Voltage Current Limited Maximum Torque (VCLMT) control method is applied to reach the maximal speed allowed. Sizing of the flywheel and the design of the Permanent magnet synchronous motor (PMSM) control will also be presented. Simulation results show the dynamic behavior of the flywheel according to the PMSM desired control as well as the energy recovery strategy.

International audience; This paper presents the supercapacitor parameters variations due to state of charge (SOC), the number of cycles (NbCy), the frequency of DC-current combined to temperature. The goal of this study consists to show the parameters evolution which can serve to determine the lifetime of supercapacitor for different conditions of use. The contribution of the paper is focused on the impacts of charge/discharge current's frequency and the temperature coupled to number of cycles on supercapacitor resistance and capacitance. The proposed method uses several DC-current profiles based on fluctuations and no fluctuations consideration. To do the supercapacitors characterization, the experimental tests based on charge and discharge operations with fluctuating DC-current are done. The experimental tests results are presented and the impacts of state of charge, the number of cycles, the frequency of DC-current and the temperature are analyzed.

U ovom radu je dan kratak pregled postupaka upravljanja višestrukim pretvaračima na zajedničkoj DC sabirnici s ciljem istodobne regulacije napona i kompenzacije opterećenja. Naglasak je stavljen na prednosti primjene hibridnog sustava za pohranu energije zasnovanog na baterijama i ultrakondenzatorima za pričuvno napajanje istosmjerne mikromreže. Potom je projektiran sustav regulacije izlaznog napona DC međukruga pretvarača uz podešenje regulacijskih krugova struje baterije i ultrakondenzatora primjenom kriterija optimuma dvostrukog odnosa. Nadređeni sustav upravljanja uključuje proporcionalno kondicioniranje reference napona (eng. droop control) radi jednostavnog omogućenja neovisnog rada više pretvarača na istoj sabirnici, te nadređeni regulator napona koji korigira stacionarnu pogrešku inherentnu konceptu „droop“ upravljanja. Sustav regulacije napona također uključuje unaprijednu kompenzaciju tereta temeljenu na kraćenju dinamike regulacijskog kruga struje. Dobiveni sustavi regulacije napona zasnovani na konceptu „droop“ upravljanja ispitani su simulacijama na računalu u režimima pojedinačnog i zajedničkog rada dvaju pretvarača, i uspoređeni sa rezultatima simulacije dobivenim primjenom koncepta centraliziranog koordiniranog upravljanja pretvaračima. In this paper, a brief overview of control approaches to multiple power converters connected to a common DC bus aimed at simultaneous voltage control and load compensation will be given. The emphasis is put on advantages of applying hybrid energy storage system based on batteries and ultracapacitors for DC microgrid auxiliary power supply. Subsequently, a power converter DC link output voltage control system has been designed along with inner current control loops of batteries and ultracapacitors that are set by the damping optimum criterion application. The superimposed control system level includes proportional voltage reference conditioning realized in the form of so-called droop control, in order to enable straightforward implementation of multiple power converters operating at the same bus, as well as the uppermost-level voltage controller which corrects the steady-state control error inherent to the droop control concept. The voltage control system also includes a feed-forward load compensator based on zero-pole cancelling approach. The voltage control systems thus obtained, based on droop control, have been verified through computer simulations for individual power converter and joint operation of the two power converters at the common DC bus, as well as compared to simulation results obtained by applying the concept of centralized coordinated power converter control.

Thin films of manganese oxides have been prepared by pulsed laser deposition (PLD) process on silicon and stainless steel substrates at different substrate temperatures and oxygen gas pressures. By proper selection of temperature and oxygen pressure during the PLD process, pure phases of Mn 2O 3, Mn 3O 4 as well as an amorphous phase of MnO x were successfully fabricated and characterized by X-ray diffraction. The pseudo-capacitance behaviors of those manganese oxides of different phases have also been evaluated by the electrochemical cyclic voltammetry in 0.1 M Na 2SO 4 aqueous electrolyte. Their specific current and capacitance determined at different scan rates were calculated and compared. The results show that polycrystalline Mn 2O 3 phase has the highest specific current and capacitance, while the values for polycrystalline Mn 3O 4 films are the lowest. The amorphous phase MnOx films have the values sitting in between those of Mn 2O 3 and Mn 3O 4. The specific capacitance of Mn 2O 3 films reaches 200 F/g at 1 mV/sec scan with excellent stability and cyclic durability. This work has demonstrated that PLD is a very promising technique for supercapacitor material research due to its excellent flexibility and capability of controlling microstructures and phases of various materials. © 2012 Trans Tech Publications, Switzerland., 7th International Conference on Processing and Manufacturing of Advanced Materials, THERMEC'2011, 1 August 2011 through 5 August 2011, Quebec City, QC

In order to safely operate the supercapacitor (SuperCap) energy storages as peak power units until the end of their lifetime in the real applications, identifying the electrical characteristics of SuperCaps and assessing the energy capacity and energy losses in fast energy conversion are the essential procedures. Until now, most methods are based on the international standard IEC 62391. However, the detected parameters (capacitance and series resistance) are not suitable enough, to precisely represent the energy capacity of the SuperCaps at different voltage levels and to estimate the power losses at different power levels. Therefore, the enhanced methods of characterizing SuperCaps in the fast charging-discharging cycles are developed. Furthermore, the energy losses due to the variation of capacitance during the charging and discharging states are evaluated, and the electrical stability of the SuperCap modules is also observed with respect to the variation of capacitance.

This paper introduces a simulation model that can be used to develop and test designs and control systems for hybrid electric vehicles (HEVs). The work involves a novel simulating platform, developed in Simulink, where each component of a series HEV is developed using a first-principles approach in a modular fashion, validated by available experimental data and then integrated to form a coupled nonlinear dynamic model. The vehicle model is capable to act as a platform for the design of supervisory control systems (SCSs) that optimize the energy flow in the powertrain. Simulations with two distinct SCSs and two driving cycles are used to analyze the vehicle performance under varying driving and operating conditions. The results demonstrate the applicability of the model for realistic prediction of both vehicle behavior and component energy losses, design optimization and control system design.

Herein, synthesis and characterization of amorphous MnO 2 and application in asymmetric aqueous ultracapacitors are reported. Different amorphous manganese oxide (MnO 2 ) materials were synthesized from the reduction of KMnO 4 in different media such as ethanol (EtOH) or dimethylformamide (DMF). The electrochemical behavior of amorphous MnO 2 , labeled MnO 2 -Et and MnO 2 -DMF, were studied by using cyclic voltammetry, impedance spectroscopy, and galvanostatic cycling in aqueous electrolyte. XRD, BET, TEM, and SEM characterizations highlighted the amorphous nature and the nanostructuration of these MnO 2 materials. BET measurement established that these amorphous MnO 2 are mesoporous. In addition, MnO 2 -Et exhibits a larger specific surface area (168 m 2 g −1 ), a narrower pore diameters distribution with lower diameters compared to MnO 2 -DMF. These results are in agreement with the electrochemical results. Indeed, MnO 2 -Et shows a higher specific capacitance and lower impedance in aqueous K 2 SO 4 electrolyte. Furthermore, aqueous asymmetric ultracapacitors were assembled and studied using amorphous MnO 2 as positive electrode and reduced graphene oxide (rGO) as negative electrode. These asymmetric systems exhibit an electrochemical stability for more than 20,000 galvanostatic cycles at current density of 1 A g −1 with an operating voltage of 2 V.

Technology advancements enable and encourage higher system electrifications in various applications. More electrified applications need more capable and higher performing sources of energy in terms of power delivery, power regeneration, and energy capacity. For example, in electric, hybrid electric, and plug-in hybrid electric vehicle applications (EVs, HEVs, and PHEVs), the power and energy ratings of the vehicle energy storage system (ESS) have a direct impact on the vehicle performance. Many researchers investigated and studied various aspects of hybrid energy storage systems (HESS) wherein multiple ESSs are combined together to share system loads, increase ESS capabilities, and cycle life. Various configurations and their application specific topologies were also proposed by other researchers; the potential of HESS has been proven to be very promising. In this research, the goal is to present the theory of a HESS configuration that has not been discovered thus far. This HESS configuration is called a series-parallel reconfigurable HESS (SPR-HESS) since it is capable of recombining multiple storage systems into different series, parallel, or series-parallel configurations, via power electronic converters, to accommodate different operation modes and load requirements. Simulations, as well as experimental verifications, are presented in this thesis. Thesis Doctor of Philosophy (PhD)

International audience; Supercapacitors (SCs) impedance modeling represents one important key to get information for SCs health monitoring and simulation. As a matter of fact, SCs behavior is dependent on various parameters such as pore size distribution of electrodes, electrolyte state, temperature, aging, etc. We propose in this study to model SC taking into account physical considerations. Basing on the theory on homogenous structure impedance, we first define the single pore model using the uniform size of pores distribution. In the second step, we attempt to generalize this circuit model considering an electrode with different pores sizes or different penetrabilities of the pores. This model called multipore (MP) model (or multipenetrability model) has been developed by our laboratories. This model allows analyzing the behavior of SC by modeling each group of electrode pores as a branch of an electrical equivalent circuit. This paper is the first in the literature to give a simple and reproducible method for MP model parameters identification. The validity of the identification method will also be verified at different SC aging rates thanks to experimental aging tests.

El presente trabajo aporta una visión de los sistemas utilizados en la actualidad, haciendo hincapié en los sistemas de almacenamiento de energía eléctrica, Baterías y Supercondensadores, mostrando simulaciones de su uso y cálculos de eficiencia. Se han utilizado los modelos aportados con Matlab Simulink 2015 para el modelado de este tipo de sistemas. Por último, se ha diseñado un sistema de control de un DC/DC que nos permite observar y verificar la mejora de los sistemas de alimentación híbridos respecto a los de alimentación única., The present work provides a generic view regarding the various energy storage system currently used, with emphasis on electrical energy storage systems, batteries and ultracaps, showing with Matlab Simulink 2015 for modeling of this type of systems, also provides a comparison between the theoretical models and the real ones that are aviable to us in the market. Finally, a control system of a DC/DC has been designed that allows us to observe and verify the importance of the hybrid power systems compared to the current ones seeing the improvement thanks to the combination of both., Grado en Ingeniería Electrónica de Comunicaciones

International audience; This paper presents ultracapacitors (U) and lithium-battery connection with an energy management strategy based on the frequency distribution approach. The module of ultracapacitors is linked to DC-bus through the buck-boost converter, and that of the lithium-battery is connected to DC-bus without a converter. DC/AC converter (inverter) and electrical machine (EM) are used to emulate the Hybrid Electric Vehicle (HEV) behavior. The contribution of this paper is focused on demand energy in HEV sharing between ultracapacitors module and battery pack according to the dynamic responses of these sources. The performances of the proposed method are evaluated through some simulations and experimental tests using a dynamic drive cycle.

Although supercapacitors are more cyclable than batteries, as they don't imply faradic reaction for energy storage, they are subject to ageing. The main ageing causes are temperature and voltage. This article investigates the effect of a supplementary ageing cause which is high frequency ripple current. Indeed, ripple current is a problem happening for DC networks using power electronics converters (as in hybrid vehicles, domestic network …). Some previous results for 1 kHz ripple current tended to show a slight effect of HF current on supercapacitors ageing speed [1]. In this article two other frequencies will be studied. The first one (100 Hz) is near from the frequency employed for domestic networks (due to rectifiers) and the second one (10 kHz) is close from the frequency of onboard power networks (due to DC-DC converters). Experimental results show that studied ripple currents are transparent in term of ageing. These results are interesting for industrial use as they prove that supercapacitors can be inserted indifferently in stationary and onboard networks without taking into account ripple currents.

A control system design based on an actively-controlled battery/ultracapacitor hybrid energy storage system suitable for direct current microgrid energy management purposes is presented in this paper. The proposed cascade control system arrangement is based on the superimposed proportional–integral voltage controller designed according to Damping Optimum criterion and a zero-pole canceling feed-forward load compensator aimed at voltage excursion suppression under variable load conditions. The superimposed controller commands the inner battery and ultracapacitor current control loops through a dynamic current reference distribution scheme, wherein the ultracapacitor takes on the highly-dynamic (transient) current demands, and the battery covers for steady-state loads. In order to avoid deep discharges of the ultracapacitor module, it is equipped with an auxiliary state-of-charge controller. Finally, for those applications where load is not measured, an adaptive Kalman filter-based load compensator is proposed and tested. The presented control strategy has been implemented on the low-cost industrial controller unit, and its effectiveness has been verified by means of simulations and experiments for the cases of abrupt load changes and quasi-stochastic load profiles using a downscaled battery/ultracapacitor hardware-in-the-loop experimental setup.

В статье рассматриваются вопросы построения математической модели силовой части DCDC преобразователя, который используется для подключения суперконденсаторов в звено постоянного тока частотно-регулируемого электропривода. Рассматривается принцип действия DC-DC преобразователя, режимы его работы, приводятся уравнения и структурная схема для описания силовой части преобразователя в составе частотно-регулируемого электропривода. В заключительной части статьи приводятся результаты моделирования. The article deals with a mathematical model of the power part of the DC-DC converter, which is used to connect the supercapacitors into the DC link of frequency-controlled electric drive. The operating principle and boost and buck modes of the DC-DC converter are considered. The functional diagram and equations for power part of DC-DC converter as a part of frequency-controlled electric drive are described. The final part of the article presents the simulations results.