Get the cable out and put it in the charging station socket – and power flows into the electric car battery? It is not quite that simple. Before charging can begin, lots of data have to be exchanged between the car and the infrastructure in order to organize the complex technical process. IAV has a test system as well as the necessary test method and know-how for detailed investigation of the communication between vehicle and charging station.
Standards ISO 15118 and IEC 61851 together with DIN Spec 70121 define the processes for communication between electric vehicle and charging infrastructure. The exchange of data such as permissible voltage or maximum charging rate can take place either with power line communication (PLC) and/or pulse width modulation (PWM). In any case, the car and charging station have to communicate before any power flows. And whether such communication is actually stable enough depends largely on the standard compliance of both infrastructure and vehicle.
There is currently no certification to safeguard this. Thorough testing is therefore all the more important to check that communication runs smoothly. IAV has a cutting-edge system for testing interoperability at the charging station, consisting of an efficient computer platform with a configurable user interface. It has a connection to the charging interface – both to the control pilot and to the live conductors.
Simulating charging station or vehicle
”We are therefore in a position to simulate the charging station and to communicate with the electric or hybrid vehicle“, explains Ursel Willrett, Senior Technical Consultant for Infrastructure Systems and Electric Mobility at IAV. ”Besides communication, our test system also supplies power for the battery as a programmable source.“ Programmable test cases are used to test all workflows of the complex protocols, including errors in particular. The entire data exchange is recorded for subsequent detailed analysis on the computer.
On the other hand, the test system can also assume the role of the vehicle to ascertain whether the charging station works in compliance with the standards. In this case, a programmable power sink is available, and all communication data are recorded for subsequent analysis. Finally, the IAV test system can also function as the ”man in the middle“. Here it is placed between vehicle and charging station to ascertain, for example, when the charging process is interrupted.
Customized testing possible
”In addition to the necessary hardware for such tests, IAV also has many communication test cases available. Furthermore, our long-standing experience puts us in a position to generate new customized test cases in next-to-no time“, says Willrett. ”Our technology and methods have already proven their worth in customer projects and we can perform such tests at any time on request.“