A distribution transformer system includes a distribution transformer and a distribution transformer monitoring (DTM) device secured to the transformer. The DTM device includes multiple sensors, a controller, and a communication interface. The sensors are configured to monitor physical properties of the distribution transformer. Each of the sensors outputs respective sensor data representative of at least one monitored physical property of the distribution transformer. The controller is configured to receive the respective sensor data from each sensor to produce received sensor data. The communications interface is in communication with the controller and configured to communicate the received sensor data to a remote system for use in determining operational parameters of the distribution transformer. In one embodiment, the distribution transformer system further includes a surge arrester associated with the distribution transformer and the DTM device includes a surge arrester sensor configured to monitor the surge arrester and output surge arrester sensor data.

A cooling fan variable-frequency control system for a power transformer includes a control device and a fan unit. The control device includes a microprocessor that is set with a first temperature range, a second temperature range higher than the first temperature range, and a fan switching time. The microprocessor is connected to a temperature sensor for detecting a temperature of an insulating oil in a power transformer. A variable-frequency controller and a fixed-frequency controller are connected to the microprocessor and are connected to a switching controller. The fan unit is connected to the switching controller and includes first and second fans. The microprocessor controls the switching controller according to the fan switching time to thereby control the variable-frequency controller to connect with the first fan or the second fan. The first fan and the second fan can operate at a fixed frequency and at a variable frequency.

A transformer hydrogen gas monitoring system according to an embodiment of the present invention may comprise: a sensor module, which is disposed to allow at least a part thereof to meet hydrogen gas in a transformer and measures a resistance value of a member having a variable resistance value according to a hydrogen concentration in the transformer; and a multi-task module for receiving a sensing result of the sensor module, generating hydrogen concentration information corresponding to resistance value information included in the sensing result, and remotely transmitting information corresponding to the generated hydrogen concentration information.

A safety device is disclosed for a power transformer containing a cooling liquid, and can include a shaped body having an inner chamber which is suitable to be at least partially immersed in cooling liquid and inside which gas can accumulate; a first floating element and a second floating element suitable to be at least partially immersed in and moved by cooling liquid; and a switch suitable to be actuated by the first floating element when the gas accumulated is such that the level of the cooling liquid in the inner chamber reaches a predetermined first threshold level and by the second floating element when the gas accumulated is such that the level of the cooling liquid in the inner chamber reaches a lower predetermined second threshold level, respectively. The first and second floating elements can be mounted on and move linearly relative to one or more corresponding guiding supports.

An electrical assembly comprising a housing forming a liquid tank inside thereof, dielectric liquid in the liquid tank, at least one fuse. and a blown fuse indication system. Each of the fuses is immersed in the dielectric liquid, and is provided with a striker pin. The blown fuse indication system is adapted to indicate a blowout of any one of the fuses by an indication signal. The blown fuse indication system comprises a first indication member and a second indication member. The first indication member is movable by the striker pins. The second indication member is immovably connected to the housing. and adapted to generate the indication signal as a response to relative movement between the first indication member and the second indication member.

A high voltage system including: a high voltage bushing having a bushing body configured to be assembled with a tank filled with a dielectric liquid wherein the bushing body has a cavity, and the bushing includes a dielectric liquid level sensor configured to measure a dielectric liquid level in the cavity, and a temperature distribution determining device configured to determine a heat distribution in the bushing based on the dielectric liquid level measured by the dielectric liquid level sensor.

The subject of the present application is a cover for distribution transformer filled with a dielectric liquid, equipped with electronic device integrated with the cover which is applied for transmission and distribution of electric energy. The cover is characterized in that the electronic device is immersed in the dielectric liquid filling a cooling compartment fixed on the cover; the cooling compartment has side walls, a top wall and a bottom wall which bottom wall is matched in the window made in the cover and the bottom wall forms a thermal barrier between the interior of the electric power device and the interior of the cooling compartment and the both interiors of the cooling compartment and of the electric power device are hermetically closed together.

A high voltage system including: a high voltage bushing having a bushing body configured to be assembled with a tank filled with a dielectric liquid wherein the bushing body has a cavity, and the bushing includes a dielectric liquid level sensor configured to measure a dielectric liquid level in the cavity, and a temperature distribution determining device configured to determine a heat distribution in the bushing based on the dielectric liquid level measured by the dielectric liquid level sensor.

A fault gas detection system for a liquid filled high voltage transformer, the transformer including a main tank and an expansion tank the tanks fluidic connected by an exchange conduit such that gas and/or a transformer liquid is able to exchange between the tanks, the gas detection system including: a chamber with a top cover, a predefined horizontal level-plane in the chamber defining a maximum liquid level of a transformer liquid in the chamber during use, a fluid-channel including a fluid-egress at a level equal to or higher than the top cover and a fluid-ingress lower than the level of the level-plane, a level sensor designed to measuring and/or indicating a liquid level.

A respective transformer and a respective wind turbine system is also provided.

A sensor assembly for monitoring an internal condition of a transformer comprising: a body for location outside a tank of the transformer, the body housing an electronics assembly including body sensors coupled to a processor; a probe extending from the body for insertion into a tank of the transformer; a number of probe sensors coupled to the processor disposed at or toward a remote end of the probe for sensing conditions within the tank; wherein the processor is configured to process signals from the probe sensors and the body sensors to produce signals for assessing one or more of: transformer core temperature; transformer insulation state; partial discharge; mechanical state of transformer; chemical state of transformer.