The present disclosure pertains to systems and methods for monitoring a capacitance-coupled voltage transformer (CCVT) in electrical communication with the electric power delivery system, the CCVT comprising a stack of capacitors and an electrical contact to a first ground connection. A first current transformer is disposed between the stack of capacitors and the first ground connection. The current transformer provides an electrical signal corresponding to a current associated with the CCVT. A second transformer is disposed to provide a second electrical signal related to the CCVT. The second signal may be a voltage signal or a current signal. An intelligent electronic device (IED) in electrical communication with the current measurement devices monitors a health factor comprising a ratio of magnitudes or a difference between phases from the transformers at a single frequency. The health factor is compared against an acceptable range and an alarm is generated when the range is exceeded.

A transformer simulation system and a measurement method for setting value simulation are disclosed. The transformer simulation system includes an oil tank, a heating device, a pump body, a first oil pipe, a second oil pipe and a first flow sensor. The heating device is disposed in the oil tank. The oil tank is provided with a first inlet and a first outlet, the first outlet is connected to the first oil pipe, and the first inlet is connected to the second oil pipe. An end of the first oil pipe away from the oil tank is a first mounting end for being connected to an oil inlet of a gas relay, and an end of the second oil pipe away from the oil tank is a second mounting end for being connected to an oil outlet of the gas relay. The pump body is connected to the first oil pipe or the second oil pipe, and the first flow sensor is disposed in the first oil pipe. The above-described transformer simulation system can measure the oil flow velocity, that is the setting value of the gas relay, and the type of the insulation oil in the oil tank can be replaced, then the corresponding setting value of the gas relay is obtained, so as to prevent the original gas relay from not playing the role of the protection due to a different property of the insulation oil.

A transformer simulation system and a measurement method for setting value simulation are disclosed. The transformer simulation system includes an oil tank, a heating device, a pump body, a first oil pipe, a second oil pipe and a first flow sensor. The heating device is disposed in the oil tank. The oil tank is provided with a first inlet and a first outlet, the first outlet is connected to the first oil pipe, and the first inlet is connected to the second oil pipe. An end of the first oil pipe away from the oil tank is a first mounting end for being connected to an oil inlet of a gas relay, and an end of the second oil pipe away from the oil tank is a second mounting end for being connected to an oil outlet of the gas relay. The pump body is connected to the first oil pipe or the second oil pipe, and the first flow sensor is disposed in the first oil pipe. The above-described transformer simulation system can measure the oil flow velocity, that is the setting value of the gas relay, and the type of the insulation oil in the oil tank can be replaced, then the corresponding setting value of the gas relay is obtained, so as to prevent the original gas relay from not playing the role of the protection due to a different property of the insulation oil.

Systems and method for detecting potentially harmful harmonic and direct current signals at a transformer are disclosed. One system includes a protection circuit electrically connected to a transformer neutral, the transformer electrically connected to a power grid, the protection circuit including a DC blocking component positioned between the transformer neutral and ground and one or more switches selectively actuated to form a path between the transformer neutral and ground in the event of unwanted DC current at the transformer neutral. The system also includes a control circuit electrically connected to the protection circuit and positioned to selectively actuate the switches based on observed conditions within the protection circuit. The system further includes a plurality of test connections disposed within the protection circuit and useable to test electrical properties of the protection circuit.

Systems and method for detecting potentially harmful harmonic and direct current signals at a transformer are disclosed. One system includes a protection circuit electrically connected to a transformer neutral, the transformer electrically connected to a power grid, the protection circuit including a DC blocking component positioned between the transformer neutral and ground and one or more switches selectively actuated to form a path between the transformer neutral and ground in the event of unwanted DC current at the transformer neutral. The system also includes a control circuit electrically connected to the protection circuit and positioned to selectively actuate the switches based on observed conditions within the protection circuit. The system further includes a plurality of test connections disposed within the protection circuit and useable to test electrical properties of the protection circuit.

An arrangement contains a polyphase transformer which has primary windings and secondary windings. The secondary windings are connected to form a star circuit, the star point of which is connected to earth potential by means of an overvoltage-limiting device. The overvoltage-limiting device has a first overvoltage-limiting component. A switch, which electrically bridges the first overvoltage-limiting component in its closed state, is assigned to the first overvoltage-limiting component.

A method monitors an electrical assembly which contains a plurality of electrical coils connected in parallel. In the method, the difference in current between the current flowing through the coils and the mean value of the currents flowing through the coils is ascertained for each of the coils connected in parallel. The differences in current are used to identify when an inter-turn short circuit occurs in one of the coils.

A high-voltage transducer includes a housing, which spatially encloses at least one electrical measuring device and an insulating gas. The insulating gas is clean air, with which electrical insulation in the housing of the high-voltage transducer is carried out. A method for measuring with the high-voltage transducer is also provided.

A method of analyzing dissolved gas in an oil-filled transformer includes determining a centroid of a polygon that represents a plurality of dissolved gas concentrations. A fault region in which the centroid of the polygon is located is determined, where the plurality of fault regions are defined in a composite fault region map that is a composite of a Duval Pentagons 1 and 2. The method classifies a fault experienced by the transformer based on the determined fault region within the composite fault region map. The classification is done by a machine learning classification technique. Further embodiments classify faults based on dissolved gas levels without determining a centroid of a polygon representing the dissolved gas levels. Related systems are also disclosed.

A method of analyzing dissolved gas in an oil-filled transformer includes determining a centroid of a polygon that represents a plurality of dissolved gas concentrations. A fault region in which the centroid of the polygon is located is determined, where the plurality of fault regions are defined in a composite fault region map that is a composite of a Duval Pentagons 1 and 2. The method classifies a fault experienced by the transformer based on the determined fault region within the composite fault region map. The classification is done by a machine learning classification technique. Further embodiments classify faults based on dissolved gas levels without determining a centroid of a polygon representing the dissolved gas levels. Related systems are also disclosed.