Battery charging systems
Contenido
Son estaciones en las que el vehículo (vehículo enchufable), se conecta directamente a la red eléctrica. Si están situados en la calle, suelen estar en plazas de aparcamiento para vehículos del segmento D o familiar. Suele incluir cuadro de acometida, cuadro de mando, con sus protectores correspondientes y línea entre el armario de acometida y los puntos de recarga.
Estos sistemas van superando problemas, como la estandarización de los mismos, ya que será necesario que los sistemas empleados por la industria sean compatibles, compatibilidad que está comenzando a converger en el sistema CCS Combo, el poder recargar con tarjeta (sistema de pago TPV), en vez de tener que usar necesariamente una aplicación (app) y el usar el protocolo abiertos de comunicación OCPI.
Uno de los principales problemas que tiene la recarga de las baterías de los vehículos eléctricos está en la disponibilidad del punto de recarga.
En los países mediterráneos, a diferencia de otros lugares, la mayoría de los vehículos están estacionados en la vía pública (solo hace falta pasear por cualquier calle de ciudad, o pueblo, y ver la dificultad que hay de encontrar aparcamiento que no sea de pago). En España algo más del 70% de los coches duermen en la calle.[4].
Por tanto, una de las soluciones es la utilización del alumbrado público, que durante el día tiene una disponibilidad de potencia, tendido de canalizaciones, acometida y protecciones eléctricas, para colocar puntos de conexión.[5] Existe un diseño basado en esta solución, que permite la instalación de puntos de recarga en cualquier sitio que exista alumbrado público, pudiendo colocarse varios puntos a partir de un cuadro de alumbrado o un punto de recarga a partir de un punto de luz, con una pequeña modificación en el cuadro eléctrico para que el alumbrado no este encendido y exista suministro eléctrico suficiente en el punto de carga.
Los cargadores son de carga lenta, dirigidos a los conductores que no disponen de una plaza de garaje para efectuar la recarga.[6] [7]Además, en España, se aprovecharía el menor precio de la electricidad por la noche, al poderse contemplar por los ayuntamientos el ofrecer puntos búho (es decir, de recarga durante toda el periodo nocturno, desde las 10 de la noche), en las zonas de la ORA y otros lugares de la ciudad.
Asimismo, se debe contemplar que en las calles nuevas o remodeladas, deba haber desde el principio, puntos de recarga para vehículos eléctricos, al mismo tiempo que se abran las calles a la circulación.
Por otro lado, las gasolineras nuevas o la situadas en autopistas y autovías, deberían de contar con la misma cantidad de puntos de recarga que de surtidores.
Horizontal buildings
In Spain, Law 49/1960, of July 21, on condominium property, establishes in its seventeenth article that if an attempt is made to install an electric vehicle charging point for private use in the building's parking lot, provided that it is located in an individual parking space, only prior communication to the community of owners that its installation will be carried out will be required. The cost of said installation will be assumed entirely by the person or parties directly interested in it.[8].
In building parking lots or newly built parking lots under a condominium regime, a main pipeline must be carried out through community areas (using tubes, channels, trays and a maximum of 10 metres), so that it is possible to make branches to the charging stations located in the parking spaces, as described in the (ITC) BT 52.
The user has the right to use their home meter to recharge according to scheme 2 of the ITC BT 52.
In other countries, advanced laws have also been created, such as, for example, one of those laws is Law number 81, known as the “Law for the Promotion of Vehicles Powered Mostly by Electricity” of Puerto Rico, which reads, and we quote verbatim:.
"...In order to promote the most effective conservation of natural resources, as well as their development and use for the general benefit of the community, the Commonwealth of Puerto Rico is determined to promote the use and commercialization of vehicles driven mostly by electricity. In accordance with the above, the Commonwealth of Puerto Rico promotes the elimination of all types of obstacles to the establishment of the necessary infrastructure for the installation and use of charging stations for vehicles driven mostly by electricity."
The same law states in its Article 5.- Establishment of Charging Stations in Condominiums:[9].
"General Rule - Any clause, condition, provision, arrangement or understanding that restricts, limits or prohibits in any way the owner of the apartment the installation or use of charging stations for vehicles driven mostly by electricity on individual parking spaces will be illegal. In any case, the charging station to be installed must comply with all applicable provisions and permits."
New buildings or parking lots
In addition to what was previously indicated regarding new parking lots on condominium property, specific electrical installations for recharging electric vehicles must be included in other newly constructed buildings or parking lots:
• - In car parks or parking lots of private, cooperative or company fleets, or those of offices, for their own staff or associates, or municipal vehicle depots, the necessary facilities to supply a charging station for every 40 spaces.
• - In permanent public car parks or parking lots (such as supermarkets, hypermarkets, restaurants, hotels...), the necessary facilities to supply a charging station for every 40 spaces.
A building or parking lot is considered to be newly constructed when the construction project is
present to the competent public administration for processing, on a date after June 30, 2015.
Ferrolinera
Fast charging stations located on interurban sections and fed by the electrical system of the catenary railway "Catenary (railroad)") are called "ferrolineras".[10].
Disappearance of system load managers
In Spain, there was the figure of the system load manager, in accordance with article 1 of Royal Decree 647/2011, of May 9.[11] A list of companies that have communicated the beginning of the system load manager activity for the provision of energy charging services was published by the CNE.[12] The figure of the load manager was repealed because it represented a burden for the deployment of charging points, as is the case with the power term.
Recharge times
A relatively simple and slow charging station with 3.6 kilowatts of power (equivalent to 230 volts at 16 amps) requires several hours to fully recharge an electric vehicle. For example, the Nissan Leaf, with a 62 kilowatt-hour battery will take approximately 17 hours to recharge (8 hours at 7.3 kilowatt-hours),[13] which can be done in the user's garage (even using the night rate) or when the user is in the office at work (also called linked charging).
However, it should be noted that most users will recharge every day, so they will rarely need to fully recharge the battery. Thus, 3.6 kilowatts of charging may be enough to recharge a vehicle parked at home or work, but never to “refuel” in the middle of a trip.
Aside from the limitations imposed by the electronic management of recharging power and battery chemistry, the greater recharging power of a station can reduce these times significantly. Currently companies around the world are developing systems based on the international standard IEC 62196, developed by the International Electrotechnical Commission (IEC), which allows the following types of plugs to be used:[14].
• - Chademo, “Charge de move”, is a fast charging standard that can supply up to 62.5 kW (500 V DC, 125 A).
• - VDE-AR-E 2623-2-2, developed in Germany by the Mennekes company, provides up to 43.5 kW (400V, 63A, three-phase) and IPXXB sealing degree.[15].
• - The SAE J1772-2009 connector, which can supply 16.8 kW (240V, 70A).
• - LIBERA series, developed by the SCAME company that provides up to 32A in three phases and IPXXD degree of tightness").
This latest rapid charging system reduces the charging time of the Nissan Leaf, charging the batteries to 80% in approximately 30 minutes (maximum percentage that is ideal for maximum battery longevity) and to 50% in 15 minutes.
But these systems must continue to be developed, since it is commonly accepted in the industry that for an average user to accept refueling in the middle of a journey, it must be done in less than 10 minutes, these are the so-called “rapid recharging systems”.
The Tesla Supercharger, from Tesla Motors, can supply up to 120 kW (compared to 50 kW for Chademo and 100 kW for SAE International). Tesla's would be the one that allows for faster recharging, further reducing the recharging time, so that it can recharge 80% of the battery in 5-10 minutes, achieving the aforementioned objective of fast charging.[16].
Technical aspects
A direct consequence of the implementation of fast charging stations is the need for an electrical infrastructure capable of supplying the demanded powers since fast charging requires an industrial-type electrical service.
The following example illustrates the power needs for an electric vehicle type:.
• - Vehicle battery: 50 kWh.
• - Charger efficiency: 100%.
• - Recharge time: 10 min (fast charge).
• - % recharge: 70% (from 10% to 80%).
With these data, the power required by the network is (0.7 x 50) / (10 / 60) = 210 kW.
For comparison, it is estimated that the average contracted power per home in Spain is 4.4 kW, so 210 kW is equivalent to the power of about 50 homes.[17].
A charging station designed for rapid charging of several vehicles at once, similar to current hydrocarbon service stations, may require peak power on the order of several megawatts, unless the station uses batteries to store the electricity it receives slowly for transfer to the vehicles quickly.
In practice, the energy efficiency of a fast charge of less than ten minutes is likely to be significantly reduced due to resistive losses or ohmic losses caused by the high currents required inside the vehicle. The lost energy is directly converted into heat, which could harm the battery itself and the vehicle's electronic equipment, so additional electrical power would be necessary to cool the equipment. The more than likely future increase in battery capacity will require a linear increase in charging power, current and heat losses, so fast charging will require new innovations as vehicles with greater autonomy are developed.
The high powers required by fast charging systems can also pose a problem for the electrical grid, causing voltage drops or even blackouts during peak hours if too many vehicles decide to charge at the same time. To try to optimize the network, vehicle charging during off-peak hours can be encouraged through reduced electricity rates. Another solution is the use of energy storage systems that reduce the difference between the demand of the charging station and the electrical grid, although this would mean a reduction in the efficiency of the system due to the inevitable load losses. Another possibility is the in-situ generation, on demand, of electrical power and solar panels.
Vehicle-to-grid (V2G) communication
Recharging the batteries of electric vehicles poses a great burden on the electrical networks, so it is necessary that, to mitigate this load, these demands be transferred to the off-peak hours of consumption. In order to be able to schedule these recharges, either the charging station or the vehicle must communicate with the “smart grid.” These systems, called Vehicle-to-grid (V2G), will allow vehicles to recharge during off-peak hours and sell electricity to the grid during peak hours.
Standardization in Europe
On June 29, 2010, the European standardization organizations, CEN, CENELEC and ETSI received mandate M-468 from the European Commission to develop a common charging system for electric vehicles.[18].
As a result of this mandate, a working group was formed with the following objectives:.
• - Ensure interoperability between chargers and the network in member countries.
• - Ensure interoperability between chargers and vehicles.
• - Consider the possibilities of smart charging of electric vehicles (V2G).
• - Guarantee safety for the user and electromagnetic compatibility.
As a result of the mandate, a Report was published.[19].
The charging standard is EN 61851"), "Conductive charging system for electric vehicles"[20] and ITC BT 52[21] based on European Directive 2014/94/EU.[22].
Based on this standard, two types of battery charging systems for electric vehicles in public access areas have been established: rapid or semi-rapid. The semi-fast charging system is one with a power equal to or greater than 15 kW, and less than 40 kW, and the fast charging system is one with a power equal to or greater than 40 kW.[23].
OCPP is a protocol that allows interoperability of stations and the management network.
In Spain, electricity distributors are investing in improving the network of charging stations along the main roads.[24].
The public charging infrastructure network in Spain reaches 46,684 operating points in the first five months of 2025.[25].