Disclosed is a phase shift transformer for supplying voltage to a plurality of unit power cells in a medium voltage inverter system. The phase shift transformer according to the present invention comprises a first bushing arranged by the side of a tank and connected to a first winding to apply high voltage and a plurality of second bushings arranged on the top of a cover and connected to each of a plurality of second windings to output low voltage, wherein three outputs of the plurality of second bushings can be applied to unit power cells.

Disclosed is a phase shift transformer for supplying voltage to a plurality of unit power cells in a medium voltage inverter system. The phase shift transformer according to the present invention comprises a first bushing arranged by the side of a tank and connected to a first winding to apply high voltage and a plurality of second bushings arranged on the top of a cover and connected to each of a plurality of second windings to output low voltage, wherein three outputs of the plurality of second bushings can be applied to unit power cells.

An electrical installation, in particular a transformer, phase shifter or inductor, which includes a fluid-filled tank having side walls, wherein, for protection against bombardment and/or fragmentation effects, the side walls are formed in a bullet-resistant manner and are made of a material having a traction strength of greater than 1000 MPa, or wherein a bullet-resistant reinforcement made of such a material is provided, the outer side of which envelope the side walls.

An electrical installation, in particular a transformer, phase shifter or inductor, which includes a fluid-filled tank having side walls, wherein, for protection against bombardment and/or fragmentation effects, the side walls are formed in a bullet-resistant manner and are made of a material having a traction strength of greater than 1000 MPa, or wherein a bullet-resistant reinforcement made of such a material is provided, the outer side of which envelope the side walls.

A system and method for detecting leakage oil with a high degree of accuracy while avoiding the complexity of the system and the influence of noise light comprise: ultraviolet light sources arranged to irradiate an oil-filled device from a plurality of different incidence angles, and are switched on and off at the respective incidence angles in sequence, and include a wavelength exciting oil; an imaging device to photograph the oil-filled device irradiated with ultraviolet light emitted from the ultraviolet light sources when the ultraviolet light sources are switched on; a recorder to record respective images photographed by the imaging device; and a display to display the respective images. The respective images are compared, a site where a light emitting position does not change always is judged as a leakage oil site, and a site emitting light or not emitting light occasionally is judged as a noise light site.

A system and method for detecting leakage oil with a high degree of accuracy while avoiding the complexity of the system and the influence of noise light comprise: ultraviolet light sources arranged to irradiate an oil-filled device from a plurality of different incidence angles, and are switched on and off at the respective incidence angles in sequence, and include a wavelength exciting oil; an imaging device to photograph the oil-filled device irradiated with ultraviolet light emitted from the ultraviolet light sources when the ultraviolet light sources are switched on; a recorder to record respective images photographed by the imaging device; and a display to display the respective images. The respective images are compared, a site where a light emitting position does not change always is judged as a leakage oil site, and a site emitting light or not emitting light occasionally is judged as a noise light site.

A stationary induction apparatus includes a core, a winding, a tank, a refrigerant, a radiator, and a unit cooler. The winding is wound around the core as a central axis. The tank contains the core and the winding. The refrigerant is filled into the tank. The radiator is mounted to the tank and includes a first heat exchange unit capable of naturally air-cooling the refrigerant that is naturally convecting while allowing the refrigerant to flow therethrough. The unit cooler is mounted to the tank and includes a pump to forcibly circulate the refrigerant, and a second heat exchange unit to forcibly air-cool the refrigerant that is being forcibly circulated while allowing the refrigerant to flow therethrough.

A stationary induction apparatus includes a core, a winding, a tank, a refrigerant, a radiator, and a unit cooler. The winding is wound around the core as a central axis. The tank contains the core and the winding. The refrigerant is filled into the tank. The radiator is mounted to the tank and includes a first heat exchange unit capable of naturally air-cooling the refrigerant that is naturally convecting while allowing the refrigerant to flow therethrough. The unit cooler is mounted to the tank and includes a pump to forcibly circulate the refrigerant, and a second heat exchange unit to forcibly air-cool the refrigerant that is being forcibly circulated while allowing the refrigerant to flow therethrough.

A transformer assembly is provided that includes a housing, transformer oil disposed within the housing, a plurality of coils of electrically conductive wire, and aliphatic polyamide insulation material operable to insulate the coils disposed within the oil. The plurality of electrically conductive coils is disposed in the housing and in contact with the transformer oil. The aliphatic polyamide insulation material includes stabilizing compounds and nano-fillers. The stabilizing compounds provide thermal and chemical stability for the insulation material.

A transformer assembly is provided that includes a housing, transformer oil disposed within the housing, a plurality of coils of electrically conductive wire, and aliphatic polyamide insulation material operable to insulate the coils disposed within the oil. The plurality of electrically conductive coils is disposed in the housing and in contact with the transformer oil. The aliphatic polyamide insulation material includes stabilizing compounds and nano-fillers. The stabilizing compounds provide thermal and chemical stability for the insulation material.