A pre-fluxing system and method to reduce inrush current for a winding used in a transformer, motor or a solenoid. The system has a primary winding and a tertiary winding connected with a power source for providing electrical energy to these windings. A pre-fluxing circuit is connected to the tertiary winding. The power source provides electrical energy to the tertiary winding via the pre-fluxing circuit, and the pre-fluxing circuit pre-magnetizes the tertiary winding when energized. The tertiary winding is configured to pre-magnetize the primary winding to reduce inrush current when the power source energizes the primary winding.

An electrical transformer system includes an electrical transformer and a depressurization system in fluid communication with an outlet of the electrical transformer. The depressurization system may include a rupture disk having a downwardly facing domed portion extending toward the outlet of the electrical transformer. The domed portion has an apex and a base with a retention portion surrounding the domed portion adjacent the base. A score line network extends circumferentially around the domed portion adjacent the base and spaced apart from the apex. The score line network includes a plurality of serrated score line segments and a plurality of hinge score line extending from the score line segments towards the apex of dome portion. The rupture disk may be interested into a housing assembly with a removable cover.

A network service and transformer safety protector on a secondary side of a network transformer tank system. The network service and transformer safety protector is positioned between the network transformer and a secondary network distribution system and is configured to connect and disconnect a transformer from the secondary network. The network service and transformer safety protector is attached to the outside of the transformer tank.

A network service and transformer safety protector on a secondary side of a network transformer tank system. The network service and transformer safety protector is positioned between the network transformer and a secondary network distribution system and is configured to connect and disconnect a transformer from the secondary network. The network service and transformer safety protector is attached to the outside of the transformer tank.

Unique systems, methods, techniques and apparatuses of a distribution system are disclosed. One exemplary embodiment is an alternating current (AC) distribution system including a first substation including a first transformer and a protective device; a first distribution network portion coupled to the first transformer; a second substation; a second distribution network portion; a DC interconnection system coupled between the first distribution network portion and the second distribution network portion; and a control system. The control system is structured to detect a fault in the first transformer or the transmission network, isolate the first distribution network from the fault, determine a set point of the DC interconnection system, and operate the DC interconnection system using the set point so as to transfer a portion of the MVAC from the second distribution network portion to the first distribution network portion.

Embodiments of the disclosure relate to systems and methods for monitoring and diagnosing transformer health. In one embodiment, a system incorporating a diagnostic apparatus for monitoring a power transformer can be provided. Various electrical current sensing elements and a dissolved gas analysis (DGA) apparatus are coupled to the transformer and to the diagnostic apparatus. The diagnostic apparatus can be configured to detect a through-fault in the transformer by executing an electrical current flow analysis based at least in part on electrical current values received from the electrical current sensing elements. The electrical current flow analysis involves comparing a ratio of a differential electrical current value and a restraining electrical current value to a threshold value. The diagnostic apparatus can also use DGA data provided by the DGA apparatus to detect an abnormal gas-related condition in the transformer. A transformer health related signal and/or a control signal that is based on the transformer health data, can be transmitted by the diagnostic apparatus.

Embodiments of the disclosure relate to systems and methods for monitoring and diagnosing transformer health. In one embodiment, a system incorporating a diagnostic apparatus for monitoring a power transformer can be provided. Various electrical current sensing elements and a dissolved gas analysis (DGA) apparatus are coupled to the transformer and to the diagnostic apparatus. The diagnostic apparatus can be configured to detect a through-fault in the transformer by executing an electrical current flow analysis based at least in part on electrical current values received from the electrical current sensing elements. The electrical current flow analysis involves comparing a ratio of a differential electrical current value and a restraining electrical current value to a threshold value. The diagnostic apparatus can also use DGA data provided by the DGA apparatus to detect an abnormal gas-related condition in the transformer. A transformer health related signal and/or a control signal that is based on the transformer health data, can be transmitted by the diagnostic apparatus.

The present invention discloses a method for quickly eliminating ferromagnetic resonance of a voltage transformer. The method includes: first sampling a three-phase voltage and an open-delta voltage of a voltage transformer; calculating a flux linkage corresponding to a zero-sequence voltage by means of an integral algorithm; and when detecting that ferromagnetic resonance occurs in the mutual inductor, further checking whether the absolute value of the flux linkage corresponding to the zero-sequence voltage or the absolute value of the open-delta voltage respectively falls within a set range, and if yes, starting a secondary resonance elimination loop for resonance elimination. The present invention also discloses a corresponding device for quickly eliminating ferromagnetic resonance of a voltage transformer. The present method and device accurately analyze and control resonance elimination trigger time based on a conventional secondary resonance elimination principle, and can effectively eliminate the impact of the core saturation of a voltage transformer on a resonance elimination process, thereby greatly improving the success probability of single resonance elimination.

A protection circuit is for a medium voltage or high voltage transformer and includes a sensing device, a measurement device, and a switching device. The sensing device is configured to be connected between a primary winding of a voltage transformer and ground potential. The measurement device is connected to the sensing device and the measurement device is configured to measure at least one parameter sensed by the sensing device. The protection circuit is configured to analyse the measured at least one parameter sensed by the sensing device. The protection circuit is configured to generate a trip signal based on the analysis of the measured at least one parameter sensed by the sensing device. The switching device is configured to receive the generated trip signal and disconnect the voltage transformer from a high voltage potential.

A protection circuit is for a medium voltage or high voltage transformer and includes a sensing device, a measurement device, and a switching device. The sensing device is configured to be connected between a primary winding of a voltage transformer and ground potential. The measurement device is connected to the sensing device and the measurement device is configured to measure at least one parameter sensed by the sensing device. The protection circuit is configured to analyse the measured at least one parameter sensed by the sensing device. The protection circuit is configured to generate a trip signal based on the analysis of the measured at least one parameter sensed by the sensing device. The switching device is configured to receive the generated trip signal and disconnect the voltage transformer from a high voltage potential.