Charging infrastructure – Portable solutions ensure successful transition to electric mobility

e-motec
June 16, 2022

Charging infrastructure – Portable solutions ensure successful transition to electric mobility

Christoph Erni

When Tesla’s first Model S electric car hit the market, e-vehicles were considered a passing fad and eyed with mistrust. As their success grew, however, the upstart tech company soon drew the attention of automotive manufacturers around the globe. No one had anticipated that Tesla could one day rival the great pioneers of the internal combustion engine. Yet, the concept has proven so successful that, today, even the most traditional automakers can no longer defy this advancing technology.

A disruptive technology revolutionises the existing order

The original trailblazers of the automotive industry, forced to completely re-orient their portfolios, had to get cracking in order not to miss the boat. This radical transformation of the complete range of motor vehicles entails complex and cost-intensive restructuring, including conversion of industrial facilities, redesigning of production lines and modification of workflows which, in turn, likewise posed permanent impacts on entire supply chains.

The challenge is to efficiently shape this process of change in ways that conserve resources. This means that every solution which helps make the transition easier, quicker and more flexible is welcome. These efforts open up opportunities for unusual cooperative arrangements. Tradition-rich brands such as Porsche, Aston Martin and Jaguar have begun seeking support from younger, stronger technology-oriented companies.

Working jointly with Jaguar, the Croatian firm Rimac has developed the drive train of Jaguar’s E-Type series and thereby created a sophisticated product that unites the experience of conventional petrol-fuelled cars with state-of-the-art electrification technologies. For its part, Rimac has risen meteorically from its status as fringe builder of electric sports cars to become one of the leading specialists in electric mobility, power electronics and battery technology.

New actors entering the scene as Tier-1 suppliers and partners in development and production

Without suitable charging technology, it’s inconceivable that this new drive technology could succeed. Portable charging stations play a key role in facilitating this success, and original equipment manufacturers (OEM) consider them the ideal solution for development and production. One reason for this is the much broader versatility such devices offer compared to stationary installed chargers. While a fix-mounted wallbox unit needs a wall or pedestal next to a production line, portable variants, in contrast, consist of an extendible cable that is hung on a compact in-cable control box (ICCB). This ensures an otherwise unattainable radius of range without losses in power output. Experience has shown that this enables quick, low-cost conversion of production and maintenance facilities for electric vehicles – as in BMW manufacturing plants, for example.

Important, too, is how easy and intuitive such portable chargers are to operate. Usually, one simple, easily readable status display with LEDs and one button suffice to regulate the charge power and control functions. It goes without saying that safety comes first. One requirement stipulates, for example, that all the charger’s components – the cable, ICCB and connections – be protected against spray water, dust and soiling, resistant to shock, falls and drops, and so ruggedly designed that they remain undamaged even if run over by a vehicle.

While petrol and diesel fuel are the only possible energy carriers for internal combustion engines, electric vehicles have to consider the different possible connectors not only at the vehicle charge port (Type 1, Type 2 or Type 3), but also at the mains power-source end (a minimum of 31 different types of household and industrial plugs). Motor vehicles are produced and marketed worldwide. The electric charging systems used in car development and production require devices able to accommodate this widely differing range thanks to exchangeable adapter plugs at either end. The adapter connections to the device must be reverse-polarity-protected, and any risk of mix-up between vehicle-end and mains-end adapters must be ruled out. The ICCB must likewise be capable of recognising and automatically regulating the charge intensity in accordance with the power source. Performance capabilities such as these make the use of portable charging devices not only user-friendly, but also safe and reliable.

Certifications ensure guaranteed safety

Electrotechnical standards defining the requirements for protecting against electric shock are in place to ensure electrical safety. For charging stations, these requirements go beyond basic protection to include fault protection, for instance. Residual current devices (RCD) suitable for this purpose can detect fault currents and breaking fault circuits within fractions of a second. This is precisely why charging stations should of course fully comply with all standards issued by the International Electrotechnical Commission (IEC).

More stringent requirements are stipulated for portable charging stations that can also serve as fixed-mounted wallbox units. Such chargers are subject to the Standard IEC 62752 governing portable charging stations, as well as IEC 61851 for stationary chargers. These requirements are supplemented by additional standards such as IEC 62196, which dictates that no current shall flow until a signal triggered by a data contact (proximity pilot, or PP for short) inside the plug confirms that an electric car has been connected to the mains.

Because the industry is relatively young and rapidly advancing, standards are being further developed continuously – based also on the experience gained from daily use. For example, repeated cases of residual currents initially occurred in one of the e-vehicle models produced by a French manufacturer. The reason, it turned out, was that designers had omitted galvanic isolation within the vehicle-internal charging system in order to cut costs. As a result, the charging station also had to assume the task of shielding the power grid from feedback of direct current. Onward development and updating of the pertinent standards based on such experience bear witness to the co-evolution of charging technology with electric vehicles.

Despite this complexity, a mere CE declaration of conformity suffices to allow market launch of products in Europe. Yet, the CE marking is nothing more than a self-declaration as judged by the manufacturer and does not prove actual compliance with all applicable standards. In contrast, product certification by impartial authorised inspection bodies experienced in the electric mobility sector confirm not only product compliance with standards, but also that they meet the highest automotive standards, and that not only industry experts but also laypeople can use the product safely.

Applying the same standards for industry as for end-customers

Whether for use on production lines or by private consumers: in principle, these devices should meet the same quality standards everywhere. For consumers, however, proven performance in the field is also important. When travelling through various countries, you should be able to easily recharge from any available power source. If no industrial-grade socket-outlet is available, it should be possible to safely and reliable charge from a conventional household socket-outlet. Portable wallbox units equipped with the right adapters fitted with integrated temperature monitoring are available on the market for this purpose. Any excessive heat-up of the power socket trips the safety feature, allowing the ICCB to shut down fully automatically and re-start charging once the socket has cooled down.

Another function not to be taken for granted, yet which is key to operation, is the charging station’s ability to consider various charging characteristics that can vary in part, depending on the vehicle brand and model. This ensures that, even when used with a different car, the charging station can continue to be used. One important requirement for charging equipment is that it be universally usable: for any vehicle, anywhere. After all, not only are car production plants located all around the world, but also the customers – car owners. So, ideally, the same product as that used by automotive manufacturers in production should be available to end-customers worldwide.

Vehicle range is a matter of primary focus for electric vehicle owners, and consequentially the required charging time and the question of fitting charging opportunities. Electric car pioneer Tesla realised this early on, and always borne charging infrastructure in mind right from the start. The secret to Tesla’s success was not to enter any market without simultaneously establishing its supercharger network. The days of those trailblazers are over, and many cities and towns now have public charging networks in operation. Nevertheless, the total number of charge points can’t hide the fact that their spatial distribution is very irregular. In areas outside of urban metropolitan regions, the density of charging infrastructure remains sketchy.

Portable wallboxes can sustainably close these gaps in the charging network by enabling e-car drivers to charge precisely where their car is parked for certain periods of time. Ever wider use of such units can make the switch to electric mobility faster and more flexible and economical. Contrary to charging stations that require permanent mounting to a wall, portable charger units offer the same functionality with the added benefit that they don’t need to be installed by an expert electrician, they can be used right way, with no fuss. Moving forward, other automakers could adopt and adapt Tesla’s approach by including high-quality charging infrastructure with every electric vehicle they deliver.

Christoph Erni, CEO, and founder of Juice Technology AG.

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