When will charging be as easy as filling up?
Bidirectional charging, WiFi at the charging station, new international standards: how umlaut is advancing interoperability
Electrical devices such as mobile phones or laptops can be charged anywhere and at any time – as long as the right cable and a handy socket are available. When travelling, an adapter for the respective region you are in provides a simple remedy. At present, this is something users of electric cars can often only dream of. Not every vehicle can be charged at every charging station, and interoperability is often not something that’s a given. When charging a smartphone, very few people suspect the cable or the socket is the cause of any charging problems. With regard to electromobility though, the current situation is different: charging problems are just as often caused by the charging station as by the vehicle itself. These interoperability problems are one of the main reasons for the present low take-up among the general public and are thus a central focus point in electric vehicle testing strategies. The path to the hassle-free charging of electric cars will require a pioneering spirit and hard work.
Around 10 years of trips to test charging station availability
When the initial, still sparsely distributed e-vehicle prototypes and isolated charging stations became available, umlaut experts were already out and about conducting their first charging station network tests. Vehicle ranges, a spotty charging station network and the speed of AC (alternating current) charging forced the test teams to load the vehicles onto trailers and transport them from one charging station to the next. The data collected during these test trips was more or less compiled by hand and the results mainly expressed whether the charging process had been successful or not.
Troubleshooting 'on the road'
Globally, the number of electric cars has increased more than 50-fold since 2012. The number of charging stations installed has also increased significantly. This not only gives end consumers a wider choice of vehicles but also makes it easier for them to use their chosen e-vehicle. At the same time, this increases the need for vehicle manufacturers to conduct trips to test the availability of charging stations in order to achieve sufficient market coverage; ensuring an adequate network of usable charging stations for their customers. 'As the market grows and complexity increases, so does the amount of data gathered to secure the charging process,' says Dr Sabine Hug, EV Charging Manager at umlaut. 'One thing quickly became apparent: we not only need to get the evaluations faster, they also have to be much more detailed.'
But there were no suitable tools for this on the market at the time. umlaut expert Dr Maximilian Boy is a software developer with years of test drive experience and remembers the time well: 'To meet our requirements and those of our customers, we couldn’t just say ‘I’m afraid this requirement can’t be tested in this way’. For example, at that time, we wrote code during the trip to enable the required data collection to be automated in the future and to be able to deliver reports to the customer on a daily basis.' By carrying out the partial automation of and adjustments to the testing process, Boy and other test engineers were able to increase the speed at which the test results were delivered. 'During the first test drive we were still creating presentations in the evenings, we were later able to provide an automatic test report for the customer straight after the data had been collected and the tests carried out,' Boy says.
charging station network tests in South Europe - 6.400 km/3.977 miles, 95 locations, approx. 150 tests
From 'black box' to breakout box
Besides the speed of data evaluation, the amount of data has also increased over the years. Without special test equipment, previously, only the error messages of the vehicle or the charging station itself could be read out. Some tests were, therefore, not feasible or remained irrelevant without any supplementary measurement data – the data ran into a kind of black box. 'Since the equipment required by our experienced testers wasn’t available in this form, our test engineers developed so-called breakout boxes themselves,' Hug explains. 'They’re plugged in between the vehicle and the charging station and so allow access to the exchanged signals and values.' Meanwhile, umlaut now has several generations of these boxes in its range – both for alternating current (AC) and direct current (DC) charging stations. There are solutions for the European-American Combined Charging System standard (CCS) as well as for the Chinese GB/T standard and a universal multi-breakout box. With this customised equipment, umlaut can now facilitate further measurements and tests, such as the measurement of charging current and voltage or even signal interruptions of the Chinese standard. 'These are important stress tests for both the vehicle and the charging station,' Hug says.
By closely cooperating with all the relevant stakeholders in the charging chain – OEMs, suppliers and charging station manufacturers – umlaut, as an objective, external consultant, is able to bundle the various interpretations of the international communication protocols and mediate between the various stakeholders. Currently, the testing teams support, among other things, the development of the international standard ChaoJi and offer specialised test equipment.
Artificial intelligence for troubleshooting
What began in the early days of the journeys to check charging station availability through tinkering and self-initiative has now been put on a professional footing by the test engineering teams: 'We’re working on fully automated evaluation of all available charging station data,' says Hug. 'To classify errors, we use machine learning solutions. What’s more, our experts are developing technologies that can test faults from the field on the test benches we already support.' In this way, some requirements, especially pure communication errors, can already be tested in advance on the test bench. 'This saves our customers time and money and lets us focus on more advanced test content during the drives,' she explains.
Global knowledge transfer
Thanks to its global position, umlaut has a network that can offer new services worldwide and thus act locally. For example, tours to test charging station availability are now being carried out in the USA, Asia and Europe. The global testing teams support each other, bundle their knowledge and skills and complement each other.
Test drives to check charging station availability today
Even today, we are still a long way from complete interoperability whereby all vehicles can be charged electrically at all charging stations. However, developments on the electromobility market still suggest a great need for innovative solutions. umlaut is on its way to achieving that and is focusing on new testing criteria and functions:
- Ease of use is an essential factor for the broad take-up of electromobility, e.g. through Plug & Charge, where the car authenticates itself at the charging station and pays without customer interaction. The requisite data security during the charging process is ensured, among other things, through Transport Layer Security (TLS) encryption to prevent misuse. umlaut is working closely with OEMs and charging station operators to successfully bring this function to market.
- From the area of user experience, new features are being added that need to be tested in addition to the standard assurance of the charging process. This includes, for example, functional WiFi for customers at the charging station.
- The technologies for bidirectional charging are becoming increasingly sophisticated. It is important to ensure the extent to which the energy of the electric vehicle can be fed back into the grid or how it is used to charge other devices.