In a transformer, forward and reverse secondary coils are connected to a single reference electrode or any of a plurality of reference electrodes. The forward secondary coil includes first and second winding portions wound around a forward iron core. The reverse secondary coil includes third and fourth winding portions wound around a reverse iron core. A first primary coil is formed around the first and third winding portions. The second primary coil is formed around the second and fourth winding portions. The single reference electrode or each of the plurality of reference electrodes is in the form of a plate.

A power electronic transformer structure includes: a support, a high-frequency transformer, a base, high-voltage side modules, and a low-voltage side module. The high-voltage side modules are respectively located at the front, top, and back of the support; the low-voltage side module is located at the bottom of the support; the high-frequency transformer is located at the middle of the support.

A power electronic transformer structure includes: a support, a high-frequency transformer, a base, high-voltage side modules, and a low-voltage side module. The high-voltage side modules are respectively located at the front, top, and back of the support; the low-voltage side module is located at the bottom of the support; the high-frequency transformer is located at the middle of the support.

A water cooling apparatus may include a first cooling tube including a first main body having a first internal space in which cooling water is provided, and a first connection pipe connected to the first main body, wherein the cooling water is discharged from the first internal space through the first connection pipe, a second cooling tube including a second connection pipe into which the first cooling tube is inserted so that the cooling water is provided from the first connection pipe to the second connection pipe, and a second main body connected to the second connection pipe, wherein the second main body includes a second internal space in which the cooling water drawn from the second connection pipe is provided, and a watertight gasket disposed on the first connection pipe, wherein the first main body and the second main body is spaced from each other with a predetermined distance.

A box-shaped inner case (3) is accommodated in a box-shaped outer case (2), and refrigerant flow passages (27) are formed at five surfaces except an opening surface (24) by gaps between the inner and outer cases. A Gap of an opening edge of the outer case (2) and an opening edge of the inner case (3) is covered with a frame-shaped cover (6). A coil (4) is placed in the inner case (3), and the inner case (3) is filled with magnetic powder mixture resin so that the coil (4) except the terminals (4a, 4b) is embedded. A core (5) is made of the magnetic powder mixture resin. Cooling water flows along a longitudinal direction of the outer case (2) with one of refrigerant pipe connecters (15) being a refrigerant inlet and the other of the refrigerant pipe connecters (15) being a refrigerant outlet.

A box-shaped inner case (3) is accommodated in a box-shaped outer case (2), and refrigerant flow passages (27) are formed at five surfaces except an opening surface (24) by gaps between the inner and outer cases. A Gap of an opening edge of the outer case (2) and an opening edge of the inner case (3) is covered with a frame-shaped cover (6). A coil (4) is placed in the inner case (3), and the inner case (3) is filled with magnetic powder mixture resin so that the coil (4) except the terminals (4a, 4b) is embedded. A core (5) is made of the magnetic powder mixture resin. Cooling water flows along a longitudinal direction of the outer case (2) with one of refrigerant pipe connecters (15) being a refrigerant inlet and the other of the refrigerant pipe connecters (15) being a refrigerant outlet.

A magnetic component includes a magnetic core and a first winding module. The magnetic core has two opposite openings and at least one magnetic column. The first winding module has a plurality of annular metal plates disposed around the at least one magnetic column. Each of the annular metal plates has an electrical connection end, an annular portion and a heat-dissipating end. The electrical connection end and the heat-dissipation end are located at the two opposite openings of the magnetic core respectively. A thermal-dissipating area of the heat-dissipating end is greater than a cross-sectional area of a connection portion between the heat-dissipating end and the annular portion.

A magnetic component includes a magnetic core and a first winding module. The magnetic core has two opposite openings and at least one magnetic column. The first winding module has a plurality of annular metal plates disposed around the at least one magnetic column. Each of the annular metal plates has an electrical connection end, an annular portion and a heat-dissipating end. The electrical connection end and the heat-dissipation end are located at the two opposite openings of the magnetic core respectively. A thermal-dissipating area of the heat-dissipating end is greater than a cross-sectional area of a connection portion between the heat-dissipating end and the annular portion.

The present invention improves cooling efficiency of a conductive member, which is formed by bundling a plurality of wires and to which electric current is led from a current introduction terminal.

A current introduction terminal structure 10, in which electric current is led from a current introduction terminal 12 to a conductive member 13 formed by bundling a plurality of wires 34, is configured in such a manner that the conductive member 13 and the current introduction terminal 12 electrically connected to this conductive member 13 are disposed in a casing 14 for storing cooling water W and are immersed in the cooling water W.

The present invention improves cooling efficiency of a conductive member, which is formed by bundling a plurality of wires and to which electric current is led from a current introduction terminal.

A current introduction terminal structure 10, in which electric current is led from a current introduction terminal 12 to a conductive member 13 formed by bundling a plurality of wires 34, is configured in such a manner that the conductive member 13 and the current introduction terminal 12 electrically connected to this conductive member 13 are disposed in a casing 14 for storing cooling water W and are immersed in the cooling water W.