A transformer assembly includes an electric transformer a temperature sensor system, and a computation unit for determining a thermal state of the electric transformer. The electric transformer includes a cooling device having at least one liquid coolant channel to absorb exhaust heat from the electric transformer a heat spreader for transferring heat from the liquid coolant to a heat dissipation surface of the heat spreader, and an air blower configured to effect an airstream along the heat dissipation surface. The temperature sensor system includes an entering coolant sensor for providing an entering coolant temperature signal, a leaving coolant sensor for providing a leaving coolant temperature signal, an entering airstream sensor for providing an entering airstream temperature signal, and a leaving airstream sensor for providing a leaving airstream temperature signal. The computation unit is configured to determine a thermal state of the transformer.

A transformer assembly includes an electric transformer a temperature sensor system, and a computation unit for determining a thermal state of the electric transformer. The electric transformer includes a cooling device having at least one liquid coolant channel to absorb exhaust heat from the electric transformer a heat spreader for transferring heat from the liquid coolant to a heat dissipation surface of the heat spreader, and an air blower configured to effect an airstream along the heat dissipation surface. The temperature sensor system includes an entering coolant sensor for providing an entering coolant temperature signal, a leaving coolant sensor for providing a leaving coolant temperature signal, an entering airstream sensor for providing an entering airstream temperature signal, and a leaving airstream sensor for providing a leaving airstream temperature signal. The computation unit is configured to determine a thermal state of the transformer.

Provided is a reactor that includes: a coil provided with a wound portion that is obtained by winding a winding wire, and has an exposed region with which a liquid coolant comes into direct contact; a magnetic core that is arranged inside and outside the wound portion, and forms a closed magnetic circuit; a sensor member configured to measure the temperature of the coil, the sensor member including a rod-shaped sensor body portion attached to the exposed region of the wound portion, and a wire coupled to the sensor body portion; and a sensor cover portion that covers surfaces of the outer periphery of the sensor body portion, except for a mounting surface for mounting to the wound portion and at least part of a coupling surface to which the wire is coupled.

Provided is a reactor that includes: a coil provided with a wound portion that is obtained by winding a winding wire, and has an exposed region with which a liquid coolant comes into direct contact; a magnetic core that is arranged inside and outside the wound portion, and forms a closed magnetic circuit; a sensor member configured to measure the temperature of the coil, the sensor member including a rod-shaped sensor body portion attached to the exposed region of the wound portion, and a wire coupled to the sensor body portion; and a sensor cover portion that covers surfaces of the outer periphery of the sensor body portion, except for a mounting surface for mounting to the wound portion and at least part of a coupling surface to which the wire is coupled.

A reactor cooling device includes a housing, a reactor arranged in the housing, and a rotating body which is rotationally located below the reactor in the housing. The rotating body and the reactor are located so as to at least partially overlap with each other in a previously selected one of turning radius directions of the rotating body. A part of the rotating body is immersed in the coolant stored in the housing. The reactor cooling device is configured to cause a part of the coolant splashed by the rotation of the rotating body to be in contact with the reactor to thereby cool the reactor.

A method and system for predicting performance of a fluid filled electrical device are provided. The system includes a sensing unit operable communicating with a fluid level estimation system. The sensing unit includes one or more sensors physically mountable on and/or around the electrical device, recording temperature data associated with the fluid and the ambient environment. The fluid level estimation system determines temperatures of the fluid and a an ambient temperature, generates feature vectors for one or more of the temperatures based on their correlation with the ambient temperature, and estimates a fluid level inside the electrical device and thereby the performance, based on the feature vectors and a probability density function derived from a distribution constructed using historical temperature gradient data associated with the electrical device.

A method and system for predicting performance of a fluid filled electrical device are provided. The system includes a sensing unit operable communicating with a fluid level estimation system. The sensing unit includes one or more sensors physically mountable on and/or around the electrical device, recording temperature data associated with the fluid and the ambient environment. The fluid level estimation system determines temperatures of the fluid and a an ambient temperature, generates feature vectors for one or more of the temperatures based on their correlation with the ambient temperature, and estimates a fluid level inside the electrical device and thereby the performance, based on the feature vectors and a probability density function derived from a distribution constructed using historical temperature gradient data associated with the electrical device.

A closed ferromagnetic housing has a pair of access ports and a center ferromagnetic post extending from and between opposite ends thereof. At least one conductor, contained within and completely surrounded by the closed ferromagnetic housing, is wound around the center ferromagnetic post such that the closed ferromagnetic housing, center ferromagnetic post, and at least one conductor form an inductor in which the ferromagnetic housing and the center ferromagnetic post define a core of the inductor and the at least one conductor defines a coil of the inductor. The access ports are configured to permit flow of coolant into the closed ferromagnetic housing and around the center ferromagnetic post to cool the at least one conductor.

A transformer assembly includes an electric transformer a temperature sensor system, and a computation unit for determining a thermal state of the electric transformer. The electric transformer includes a cooling device having at least one liquid coolant channel absorb exhaust heat from the electric transformer a heat spreader for transferring heat from the liquid coolant to a heat dissipation surface of the heat spreader, and an air blower configured to effect an airstream along the heat dissipation surface. The temperature sensor system includes an entering coolant sensor for providing an entering coolant temperature signal, a leaving coolant sensor for providing a leaving coolant temperature signal, an entering airstream sensor for providing an entering airstream temperature signal, and a leaving airstream sensor for providing a leaving airstream temperature signal. The computation unit is configured to determine a thermal state of the transformer.

A transformer assembly includes an electric transformer a temperature sensor system, and a computation unit for determining a thermal state of the electric transformer. The electric transformer includes a cooling device having at least one liquid coolant channel absorb exhaust heat from the electric transformer a heat spreader for transferring heat from the liquid coolant to a heat dissipation surface of the heat spreader, and an air blower configured to effect an airstream along the heat dissipation surface. The temperature sensor system includes an entering coolant sensor for providing an entering coolant temperature signal, a leaving coolant sensor for providing a leaving coolant temperature signal, an entering airstream sensor for providing an entering airstream temperature signal, and a leaving airstream sensor for providing a leaving airstream temperature signal. The computation unit is configured to determine a thermal state of the transformer.