A folk festival as a field test: The low voltage distribution network under the microscope (WK-intern) - Stuttgart's folk festival on the "Wasen" is one of the largest folk festivals in Europe, and proves a challenge for the grid operator in Stuttgart every year In 2015, it also served as a field test. Mobile measuring boxes captured all load flows in the ten local secondary substations on the festival site precisely to the second. The measurements not only increase the supply assurance of a folk festival. In the mid-term it is also intended that such measures will toughen up the entire distribution network