To reduce CO2 and keep the air at ports clean, more and more shipyards are using electric drive systems. More electronics are also being installed on board at the same time. Therefore, problems familiar to experts from industrial companies are occurring more and more: harmonics interfering with plant grids. The technology on ships is even more prone to failure, since the on-board power supplies are microgrids. Compared to shore grids, they have a significantly lower short-circuit capacity. And the shore power supply for ships at anchor also has its flaws, since the grid frequency on board is different than it is on land. Technology from Reinhausen can help overcome the challenges in shipping. Two examples: