The present disclosure pertains to devices, systems, and methods for monitoring an electric power system. In one embodiment, a system may detect a failure in an electric power system. The system may include a communication interface to receive a first indication related to a condition in the electric power system, and a second indication related to the condition. The system may also include a test subsystem to compare the first indication to the second indication and to determine a discrepancy between the first indication and the second indication. A diagnostic subsystem may identify the failure based on the discrepancy between the first indication and the second indication. An alert subsystem may generate an alert based on the failure.

A method of protecting a power transformer including: monitoring an external fault indication signal; carrying out locally a fault determination; carrying out locally an inrush current determination; and issuing a final trip signal to protect the power transformer if the external fault indication signal identifies that a fault has occurred and the locally carried out fault determination confirms that a fault has occurred; or the external fault indication signal identifies that a fault has occurred and the locally carried out fault determination identifies that no fault has occurred but after a predetermined delay the locally carried out inrush current determination confirms the absence of an inrush current.

A method of protecting a power transformer including: monitoring an external fault indication signal; carrying out locally a fault determination; carrying out locally an inrush current determination; and issuing a final trip signal to protect the power transformer if the external fault indication signal identifies that a fault has occurred and the locally carried out fault determination confirms that a fault has occurred; or the external fault indication signal identifies that a fault has occurred and the locally carried out fault determination identifies that no fault has occurred but after a predetermined delay the locally carried out inrush current determination confirms the absence of an inrush current.

A control device for an electrical protection circuit for use in an alternating current system including a transformer is disclosed. An example system includes a first measurement probe, a second measurement probe configured to measure an electrical property within the electrical protection circuit, and a control module, including a processing device. The control module is configured to monitor a measurement from the first measurement probe and transmit a protection activation control signal to the switch assembly based on the measurement from the first measurement probe exceeding a first predetermined threshold. The control module is also configured to monitor a measurement from the second measurement probe and transmit a protection deactivation control signal to the switch assembly based on the measurement from the second measurement probe satisfying a second predetermined threshold.

A control device for an electrical protection circuit for use in an alternating current system including a transformer is disclosed. An example system includes a first measurement probe, a second measurement probe configured to measure an electrical property within the electrical protection circuit, and a control module, including a processing device. The control module is configured to monitor a measurement from the first measurement probe and transmit a protection activation control signal to the switch assembly based on the measurement from the first measurement probe exceeding a first predetermined threshold. The control module is also configured to monitor a measurement from the second measurement probe and transmit a protection deactivation control signal to the switch assembly based on the measurement from the second measurement probe satisfying a second predetermined threshold.

A method determines temperature information associated with a current coil connection in a meter. The method includes conveying heat from a current coil connection to a location proximate a winding disposed about a core. The core includes an opening through which a current carrying coil is disposed, the current carrying coil carrying current measured by the meter. The method also includes measuring a resistance of the winding disposed about a core, wherein the winding has a resistance that varies as a function of temperature. The method includes determining a temperature value based on the measured resistance and storing or communicating the determined temperature value.

A method determines temperature information associated with a current coil connection in a meter. The method includes conveying heat from a current coil connection to a location proximate a winding disposed about a core. The core includes an opening through which a current carrying coil is disposed, the current carrying coil carrying current measured by the meter. The method also includes measuring a resistance of the winding disposed about a core, wherein the winding has a resistance that varies as a function of temperature. The method includes determining a temperature value based on the measured resistance and storing or communicating the determined temperature value.

The invention is related to a monitoring and protection device of power distribution transformers on the low voltage side. Said device monitors in a permanent manner the functioning of the transformer and provides a record of all the information in case of a fault. Additionally, the invention device provides the protection of the transformer in case of a fault, allowing a partial impact on the service and preventing peak currents that may reduce the useful life of the transformer. The device has a remote communication module that allows the transmission of the recorded data, a control module that may be activated remotely and a visual alert module that reduces the risk in the handling of the device.

The invention is related to a monitoring and protection device of power distribution transformers on the low voltage side. Said device monitors in a permanent manner the functioning of the transformer and provides a record of all the information in case of a fault. Additionally, the invention device provides the protection of the transformer in case of a fault, allowing a partial impact on the service and preventing peak currents that may reduce the useful life of the transformer. The device has a remote communication module that allows the transmission of the recorded data, a control module that may be activated remotely and a visual alert module that reduces the risk in the handling of the device.

Provided is an apparatus and method for controlling a circuit breaker for a static synchronous compensator (STATCOM) such that the circuit breaker installed in a branch line for the STATCOM is operated according to the current control characteristics of the STATCOM, the apparatus including: a transformer protector for detecting the differential current between primary current and secondary current of a transformer connected in series to the circuit breaker in the branch line, and controlling the opening/closing of the circuit breaker; and a STATCOM controller for controlling an operation of the STATCOM, wherein the STATCOM controller outputs, to the transformer protector, an opening suspension signal for suspending the opening of the circuit breaker when overvoltage occurring in the STATCOM is detected, and the transformer protector suspends output of a circuit breaker opening signal to the circuit breaker according to the received opening suspension signal.