Power transformer
A power transformer, including a core and a winding is provided. The core includes a limb and a yoke. The winding is wound around the limb and has an extension along a main axis of the limb. The power transformer further includes an energy harvesting device coupled to at least one of the core or the winding. The energy harvesting device includes a ferromagnetic part and a coil wound around at least a portion of the ferromagnetic part. The energy harvesting device is arranged in such a way that a part of a magnetic flux MF generated in the power transformer induces an electromotive force in the energy harvesting device. The coil includes a wire wound around a main axis of the coil and has an extension along the main axis of the coil.
1 . A power transformer, comprising a core, wherein the core comprises a limb and a yoke;
a winding wound around the limb, wherein the winding has an extension along a main axis of the limb;
an energy harvesting device comprises a ferromagnetic part and a coil wound around at least a portion of the ferromagnetic part;
wherein the energy harvesting device is arranged in such a way that a part of a magnetic flux generated in the power transformer induces an electromotive force in the energy harvesting device;
wherein the coil comprises a wire wound around a main axis of the coil;
wherein the coil has an extension along the main axis of the coil which is less than the extension of the winding;
wherein the energy harvesting device is designed and arranged to power a sensor of the transformer for sensing at least one of temperature, humidity, and pressure; wherein the energy harvesting device has a first end portion attached to the limb and a second end portion attached to the yoke and wherein the limb is connected with one end to the yoke and with a second, opposing end to a further yoke of the core; and
wherein the ferromagnetic part is attached to the core via at least one permanent magnet.
2 . The power transformer of claim 1 , wherein the extension of the coil is less than 10% of the extension of the winding.
3 . The power transformer of claim 1 , wherein the power transformer further comprises a tank filled with oil, wherein the core and the winding are at least partially submerged in the oil.
4 . The power transformer of claim 1 , wherein the ferromagnetic part includes or consists of laminated silicone steel.
5 . The power transformer of claim 1 , wherein the coil includes a copper wire.
6 . The power transformer of claim 5 , wherein the copper wire has a diameter of 0.1 mm or less.
7 . The power transformer of claim 1 , wherein the permanent magnet includes Neodymium or consists of Neodymium.
8 . The power transformer of claim 1 , further comprising a tank filled with oil, wherein the core and the winding are at least partially submerged in the oil, and wherein the sensor is disposed within the tank.
9 . The power transformer of claim 1 , wherein the power transformer is a 50/60 Hz power transformer.