Kiertojännityksellä

Kiertojännityksellä is a Finnish term that translates to "circulating current" or "circulating electricity" in English. It refers to an undesirable electrical current that flows in a closed loop within a conductive material or structure. This phenomenon is often encountered in electrical systems, particularly those involving transformers, large conductors, or metallic structures that are in close proximity to alternating magnetic fields.

The generation of kiertojännityksellä is typically due to electromagnetic induction. When a changing magnetic flux passes through a conductive path, it induces an electromotive force (EMF), which in turn drives a current. In the context of electrical equipment, this can happen in the metal casing of a transformer or the structural steel of a power plant. The induced current can flow through unintended pathways, forming a closed circuit.

The primary consequence of kiertojännityksellä is energy loss in the form of heat due to the resistance of the conductive path. This can lead to increased operating temperatures, reduced efficiency, and in severe cases, damage to equipment. For instance, in transformers, circulating currents in the core or casing can cause overheating and insulation degradation. Mitigation strategies often involve designing systems to minimize the formation of these loops or to increase their resistance, thereby reducing the magnitude of the circulating current. This can include using laminations in transformer cores to break up the conductive paths or employing specific grounding techniques.