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This paper presents a hybrid characterization procedure of battery packs capable of reproducing their behavior under different dynamic operation conditions. During the experimental procedure, both time and frequency tests are performed. These tests have been carried out on a commercial battery pack, instead of a single cell, in order to include packaging effects as well as performance of battery pack devices in real electrical applications. As a result of this procedure the battery pack model has been experimentally validated for four cases based on real electrified transportation and grid applications. Additionally, the model response has been compared with the widely used Partnership for a New Generation of Vehicles (PNGV) model. The validation tests show that the proposed battery pack model reproduces the dynamic battery response with better accuracy than the PNGV for all analyzed cases.

This paper presents the evaluation of the energetic performance of the battery-pack from the motorcycle prototype EME 16E. This racing prototype was developed by a student team from the Universidad Polit&eacute, cnica de Madrid (UPM) to participate in the MotoStudent competition during 2015&ndash, 2016. This study includes the sizing and assembly of the motorcycle&rsquo, s battery-pack under strict regulations and a limited budget. The prototype was also tested under different performance conditions, such as laboratory tests and racing circuits. Experimental results show that the proposed battery-pack is capable of supplying the energy and power necessary to drive the motorcycle in all cases analyzed.

Climate change motivated by human activities constitutes one of the main challenges of this century. To cut carbon emissions to mitigate its dangerous effects, the current energy generation mix should be shifted to renewables sources. The main drawback of these technologies is their intermittency that will require storage systems to fully integrate them in the generation mix, allowing them to be more controllable. In recent years great progress to develop an effective and economically feasible energy storage systems, particularly motivated by the recent rise of demand for electric transportation has been made. Lithium-ion (Li-ion) battery prices have fallen near 90% over the past decade, making possible the affordability of electric vehicles and transforming the economics of renewable energy. In this paper, we evaluate the energy storage requirements for a carbon-free scenario in Spain, analyzing the CO2 emissions reduction.

This article presents the optimization procedure based on genetics algorithms (GA) to obtain an equivalent electric circuit model (EECM) of a Li-ion battery pack. In the first part, a series of experimental tests in time and frequency domains were carried out. These tests were used to identify the parameters of the EECM under different State-of-Charge (SoC) for a commercial battery-pack. Each EECM consists of a voltage source connected in series with a resistor and a set of k networks composed of a resistor in parallel with a capacitor, where k = 1, 2 o 3 (1RC, 2RC, and 3RC). Subsequently, parametric identification of the EECM was performed using optimization techniques. At this stage, the topology that gives the lowest estimation error was determined, where the options analyzed were to use 1RC, 2RC, or 3RC networks. The objective function consists of minimizing the mean square error between measured and calculated impedances of the different proposed circuit models. GA was used to solve this optimization problem. The minimum error obtained was 1.07% and 1.05% for the EECM with 2RC and 3RC networks, respectively. Finally, these EECMs were implemented in Matlab®/Simulink to validate the Li-ion battery-pack model response for an electric vehicle application. A hardware-in-the-loop (HIL) simulation platform was developed to simulate the performance of an electric vehicle (EV) under different driving cycles. The results show that the GA-based approach allows obtained an EECM of low order to represent the highly dynamic behavior of a Li-ion battery with high accuracy.

Railway electrification is experiencing a very important transformation process today. The need of increasing its capacity has evidenced the drawbacks of conventional systems of dealing with the higher power required, whilst maintaining reasonable costs. Furthermore, the current trend undertaken by electrical systems towards smarter grids involves to rethink carefully the direction of evolution of these systems. However, the different technical progress at the time of railway electrification, and the particular historical and economic characteristics of the countries, have led to a great variety of configurations that require different solutions. The first main objective of this article is to classify and describe the principal electrical railway power supply systems existing and the most important proposals for their improvement found in the literature. The second main objective is to make a comparison of all presented systems based on economic and technical criteria capable of assessing their suitability and future projection. The right choice of the feeding system is decisive for the development of more competitive, efficient and reliable railway systems.

This paper proposes a standard and flexible test bench architecture for the testing and modeling of electrochemical energy modules. It also presents a comprehensive methodology that enables to obtain accurate models under realistic operating conditions with a low computational cost. For this purpose, three different configuration modes of the experimental architecture setup are introduced. Finally, the test bench architecture and the experimental methodology proposed have been validated by the modeling and testing of a Li-ion battery pack and a supercapacitor module.

The introduction of electric vehicles (EVs) is another alternative to reduce GHG emissions in these isolated systems, because these vehicles are more suitable for the short average daily distances on the islands. EVs can also contribute to integrating renewable energies in these isolated systems, becoming flexible loads and helping to reduce the peak-valley ratio and flattering the energy demand curve. Additionally, the mobility characteristics in islands make them appropriate to promote the electrification of the transportation sector. Introducing V2G as an energy storage system presents advantages such as making use of large-scale distributed storage systems; the batteries of EVs present very low cost for grid operators, easy implementation, and compatibility with the environmental policy. In this work the option of charging an EV fleet as a distributed energy storage system to increase the participation of renewable energy in an isolated power system has been presented.

Even though the Li-ion battery price has dropped significantly in recent years, this storage technology is still quite expensive and, in order to avoid overspending, this study proposes using EV's batteries as Battery Energy Storage System. One of the main disadvantages of this scheme is that the total available battery's capacity is variable, but it is dependent on the EV's mobility. In this chapter, an optimization model is developed to minimize the electricity cost purchased from the utility grid by the building manager. This optimization model takes into account several parameters: the availability of the EVs parked at the parking lot (that affects the available storage capacity, which varies at each time period, as EVs come and go along the day), the total energy consumption demanded by the building, the self -PV generation and, finally, the retail energy prices. With this information, the optimization algorithm determines how the EV batteries' charge/ discharge of all parked vehicles should be managed to minimize the cost of electricity purchased from the grid.

Electric vehicles (EVs) are a major component of future electric grids, both for the increase in electricity demand and the flexibility they can add to the grid. Vehicle-to-grid and vehicle-to-building pilots have been tested and some have been approved by grid operators, but the EVs' possibilities shall be further enhanced. In previous works, the authors proposed a peer-to-peer energy market between EVs that largely reduced the expenses of their costly day-charging. This chapter further expands the model by taking into account the long-term effects of the market, which reduce the impact of the electric grid prices forecast on the market. The ratio between EVs that offer energy and those that demand energy is shown to be a good indicator for the market price forecast. Almost all energy demand occurs in pairs zone-time in which the number of offering EVs is more than five times the number of demanding EVs, for which the market price is very close to the electricity price at night.

In this chapter, a hybrid modeling procedure of Li-ion battery modules is presented. From experimental results, the parameters of an electrical circuit have been determined by means of time- and frequency-domain tests. In this way, the dynamic behavior of the battery-pack is modeled. The tests have been performed at the whole battery-pack, instead of a single-cell approach, in order to consider the packaging effects of multicell devices. The real performance of the battery-pack under dynamic applications associated with distribution grids has been simulated using a hardware-in-the-loop (HIL) experimental setup. According to simulation results, the hybrid model follows the battery-pack response with high accuracy.

Self-consumption is a growing public demand in an energy environment with growing electricity costs and decreasing photovoltaic installation costs. Shared self-consumption is an imperative aspect for bringing self-consumption into Multi-Family Residential Buildings (MRB), where most families live. Nevertheless, current legislation in most countries does not consider shared self-consumption or does not exploit its full potential; such is the case of Spain or Portugal. This paper will present a novel optimization problem for studying the economics of a shared self-consumption installation in a MRB (composed of five family demands, a PV installation and a battery) with the aim of reducing the total bill of the MRB during an entire year. The impact on energy communities of two different types of energy policies is analysed: the remuneration scheme for the surplus energy (net metering, net billing, and exclusive self-consumption policies) and the regulation for shared self-generated energy (demand-dependent, proportional output and no sharing). It is found that the regulation for the sharing energy can be more important that the remuneration scheme, which has been the traditional target of the self-consumption policy.

Half of the global population already lives in urban areas, facing to the problem of air pollution mainly caused by the transportation system. The recently worsening of urban air quality has a direct impact on the human health. Replacing today’s internal combustion engine vehicles with electric ones in public fleets could provide a deep impact on the air quality in the cities. In this paper, real mobility information is used as decision support for the taxi fleet manager to promote the adoption of electric taxi cabs in the city of San Francisco, USA. Firstly, mobility characteristics and energy requirements of a single taxi are analyzed. Then, the results are generalized to all vehicles from the taxi fleet. An electrificability rate of the taxi fleet is generated, providing information about the number of current trips that could be performed by electric taxis without modifying the current driver mobility patterns. The analysis results reveal that 75.2% of the current taxis could be replaced by electric vehicles, considering a current standard battery capacity (24–30 kWh). This value can increase significantly (to 100%), taking into account the evolution of the price and capacity of the batteries installed in the last models of electric vehicles that are coming to the market. The economic analysis shows that the purchasing costs of an electric taxi are bigger than conventional one. However, fuel, maintenance and repair costs are much lower. Using the expected energy consumption information evaluated in this study, the total spatio-temporal demand of electric energy required to recharge the electric fleet is also calculated, allowing identifying optimal location of charging infrastructure based on realistic routing patterns. This information could also be used by the distribution system operator to identify possible reinforcement actions in the electric grid in order to promote introducing electric vehicles.

This paper presents an experimental procedure to optimize the battery pack capacity of an electric motorbike designed to run on the MotoStudent International Competition of 2016. The optimization process has been realized by means of experimental tests, which have been carried out in a load bank testbench. This automated testing station was designed specifically to test the battery cells of the motorbike battery-pack. As a result of the optimization process the maximum difference between the highest module and the lowest module of the motorbike battery pack has been substantially reduced compared to a randomly located configuration.)

The so-called advanced DC converter-based railway power supply system is presented as a very promising configuration capable of overcoming the principal drawbacks of conventional systems whilst providing additional advanced functionalities. The main objective of this paper is twofold. Firstly, to introduce a simulation model capable of determining the steady state operation of advanced and traditional systems. Secondly, to conduct an analysis and comparison of the systems performance for a high speed railway line.

This work analyzes the effects of a BMS (battery management system) on the characterization and modeling of series and parallel connections of Li-ion cell packs. The Li-ion pack studied consists of four series modules connected in parallel. This pack has been characterized by means of charge, discharge and frequency tests. As a result of these tests, series and parallel influence on battery parameters have been determined. A model considering the effects of a BMS is established and compared with a model based on a single-cell approach. Experimental validations show that the single cell based approach gives poor results in comparison with a model that considers BMS effects.