The infrastructure of smart metering systems is used in the BDL project to implement use cases that enable the integration of bidirectional electric vehicles into the grid operation. Among others, the transmission of power specifications by the grid operator to the charging station via the smart meter gateway (SMGW) is implemented. This enables the grid operator to resolve congestions in the grid. For this use case, a performance analysis was carried out by FfE, in which the general reliability, the required data volume, and the process time from sending the specification to its arrival at the charging station were examined. The results were presented on 15.09.2022 at the “DACH Energy Informatics 2022” conference in Freiburg and published by Springer Verlag.
A test environment was set up for the investigations. The commands were carried out by a server operated by FfE and sent to a gateway administration system. The SMGW device used for the tests was the device of the demonstration panel. Instead of a charging point, a RaspberryPi was connected to it containing software that emulates the charging point’s behaviour. Figure 1 shows the test setup containing communication paths, the data collection and transmission to the server for evaluation.
Data Collection and Results
Log records of all devices involved along the process chain were used for data collection and all network traffic was recorded. Over 2,000 commands were executed in the test series and over 3 million data points were analyzed in total. A rate of 98.2 % of successfully transmitted commands for the overall reliability was determined. The average amount of data involved is 14.97 kB when transmitting a command. The latency from sending the command until the reaction is 51 seconds on average, provided that a communication channel has been set up. Thus, the requirements for the use case of power specification by the grid operator considered in BDL are fulfilled under the condition that the capacity of the communication infrastructure is in accordance with the number of controllable components.