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.

A fault interrupting switching device that is part of a transformer in an underground residential power distribution circuit and provides fault isolation and restoration. The switching device includes a vacuum interrupter having a fixed terminal and a movable terminal, where the fixed terminal is electrically coupled to a transformer interface and the movable terminal is electrically coupled to a connector interface. A control rod is coupled to the movable terminal and an actuator assembly is coupled to the control rod and is operable to move the control rod to open and close the vacuum interrupter. An electronics assembly electrically is coupled to the movable terminal, and includes a high voltage capacitor and an energy storage capacitor, where the high voltage capacitor provides power to operate the actuator when the vacuum interrupter is open and the energy storage capacitor provides power to the electronics assembly when the vacuum interrupter is closed.

A fault interrupting switching device that is part of a transformer in an underground residential power distribution circuit and provides fault isolation and restoration. The switching device includes a vacuum interrupter having a fixed terminal and a movable terminal, where the fixed terminal is electrically coupled to a transformer interface and the movable terminal is electrically coupled to a connector interface. A control rod is coupled to the movable terminal and an actuator assembly is coupled to the control rod and is operable to move the control rod to open and close the vacuum interrupter. An electronics assembly electrically is coupled to the movable terminal, and includes a high voltage capacitor and an energy storage capacitor, where the high voltage capacitor provides power to operate the actuator when the vacuum interrupter is open and the energy storage capacitor provides power to the electronics assembly when the vacuum interrupter is closed.

A switching device that is part of a transformer in an underground residential power distribution circuit and provides fault isolation and restoration. The switching device includes a transformer interface for coupling the device to the transformer and a connector interface for coupling the device to a connector. The device also includes a vacuum interrupter having a fixed terminal and a movable terminal, where the fixed terminal is electrically coupled to the connector interface and the movable terminal is electrically coupled to the transformer interface. A control rod is coupled to the movable terminal, an actuator assembly is coupled to the control rod and is operable to move the control rod to open and close the vacuum interrupter. A capacitor is electrically coupled to the fixed terminal, and provides an interface for power line communications signals, voltage sensing, help determine power flow direction and help determine the distance to a fault.

A switch assembly that is part of a transformer in an underground residential power distribution circuit and that provides fault isolation and restoration. The switch assembly includes first and second switching devices each having an outer housing, a transformer interface electrically coupled to the transformer, a connector interface electrically coupled to a first connector and a first vacuum interrupter having a fixed contact and a movable contact, where the fixed contact is electrically coupled to the connector interface and the movable contact is electrically coupled to the transformer interface. A control board controls the first and second switching devices, where the control board is responsive to voltage signals from capacitors in the first and second switching devices.

A method for isolating a fault in an underground power distribution network. The network includes a power line, a plurality of transformers electrically coupled to and positioned along the power line, a first recloser connected to one end of the power line and a second recloser connected to an opposite end of the power line, where each transformer includes an upstream switching device and a downstream switching device, and where power is provided to both ends of the power line through the first and second reclosers and one of the switching devices is a normally open switching device. The method includes detecting overcurrent by some of the switching devices, detecting loss of voltage by some of the switching devices and sending clear to close messages to some of the switching devices to open and close certain ones of the switching devices to isolate the fault.

A transformer assembly including a transformer that is part of an underground residential power distribution circuit and that provides fault isolation and restoration. The transformer assembly includes an enclosure enclosing a primary winding and a secondary winding. The transformer assembly also includes first and second switching devices mounted to a panel of the enclosure, where each switching device includes an outer housing, a transformer interface electrically coupled to the primary winding, a connector interface electrically coupled to a first connector and a vacuum interrupter having a fixed contact and a movable contact. The fixed contact is electrically coupled to the connector interface or the transformer interface and the movable terminal is electrically coupled to the other connector interface or the transformer interface.

A method for isolating a fault in an underground power distribution network. The network includes a power line, a plurality of transformers electrically coupled to and positioned along the power line, a first end switch connected to one end of the power line and a second end switch connected to an opposite end of the power line, where each transformer includes an upstream switching device and a downstream switching device, and where source power is provided to both ends of the power line through the first and second end switches and one of the switching devices is a normally open switching device. The method includes detecting overcurrent in the network from the fault, opening certain ones of the switching devices in response thereto, detecting loss of voltage as a result of the open switching devices and opening or closing certain ones of the switching devices to isolate the fault.

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.