March 2022

Dear Readers,

The world is closer day by day with the advances in transportation and, it results in widely diverse cultures and diseases. The fast spread of Covid 19 is a side effect of this global village, however, science and modern bioengineering are making it possible to overcome and expected to meet the endemic soon.

The city of Oviedo has renewed its urban bus fleet this year 2022. The company ALSA and the City Hall have purchased 19 Mercedes Benz Citaro Hybrid, 1 eCitaro full electric, and 2 Sprinter City 75 vans with low emissions[1]–[3]. These buses accounted for 38% of the total fleet, which is now ECO or Zero Emissions (according to EURO VI regulations). On top of that, with this purchase, the urban bus fleet's average age is reduced to 4.3 years.

Abstract
Smart grids have important challenges for incorporating electrical mobility, especially in emerging countries. Due to new requirements associated with ultra-grid penetration, electrical mobility, and the new aspects of the medium voltage grids; it could be a limit for this technology without a new infrastructure or changes in the grid. In this research, a new methodology is proposed with seven steps. For electrical mobility in Perú, the electrical networks with Photo-voltaic Solar panels and fast-charging stations for emerging countries have new effects as overload in transformers, inverter control and modeling for chargers and distribution transformers should be reviewed, due to loads transfer, voltage sag, and losses, the impact is high in a short term. These results provide challenges for government, industry, and prosumers. Results have demonstrated voltage sag are from 5.68% to 3.81%, losses from 0.112kW to 0.12kW, voltage transformer from 1.21% to 1.09%, and transformers rotations with a detailed load density analysis with 20% penetration with fast charging stations and 40% of ultra grid penetration with photo-voltaic generators, with original mitigation associated to control in inverters and seven steps in the methodology.

Thermal runway (TR) is one of the major problems associated with Lithium (Li) ion batteries. In technical parlance, it is also known as the “venting of flame”, with the temperature playing a significant role. The operating temperature of the Li-ion batteries ranges from +15 and +45ºC. It is imperative for the battery to function within this range as otherwise; it may compromise the functional safety of the battery, the full vehicle system well as the electrical accessories. TR happens when the temperature goes above the critical level and results in an unstoppable chain reaction. There is a steep increase in the temperature in a very short interval of time (in milliseconds) leading to a sudden release in the energy stored in the battery. Temperature magnitudes close to 400°C are created, making the battery gaseous, resulting in fire eruption which is not extinguishable by traditional methods. At temperatures close to 60°C, there is an increased risk of a TR which would be extremely critical at 100°C. TR in Li-ion batteries can be caused by various sources like mechanical, electrical, and thermal abuses. This results in smoke emerging out and finally, the battery catches fire. The fire propagates to its neighboring cells and causes an explosion. Fig. 1 depicts the different causes and the effect of thermal runaway in Li-ion batteries.

From the Co-Editor-in-Chiefs - JinWoo Ahn and Sheldon Williamson

Regional News - Oviedo – Principality of Asturias – Spain

Electrical Mobility and Ultra Grid Implementation Problems in Emerging Countries

Thermal Runway in Lithium-Ion Battery for Mobility Applications

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