An on-load tap changer that includes an actuator configured to adjust a turn ratio of the transformer, and a processing unit configured to control the actuator and to communicate with a control device via a digital signal connection. The processing unit is further configured to receive a status detected by a sensor. A method of manufacturing the on-load tap changer is also disclosed. Embodiments according to the present disclosure provide a digitalized on-load tap changer that allows various statuses to be monitored or controlled, by which various advantages can be achieved. For example, the life of a contact of the transformer can be predicted. Other data can be used to determine whether it is safe to adjust the contact of the transformer. Moreover, the optical fibers between the on-load tap changer and an external device enable an isolated transmission of control and data signals that almost eliminates interferences.

A method of monitoring the temperature of a solid state switch in an aircraft solid state power controller. The method includes: measuring an electric current (I) flowing through the solid state switch; calculating, based on the measured electric current (I), an introduced electric power (P.sub.el) that is introduced into the solid state switch within the predefined time period (?t); calculating an increase in temperature (?T) of the solid state switch that is caused by the introduced electric power (P.sub.el); calculating an actual temperature (T.sub.act) of the solid state switch by adding the calculated increase in temperature (?T) to an ambient temperature (T.sub.amb); and comparing the calculated actual temperature (T.sub.act) with a predefined temperature threshold (T.sub.th) and determining an overheat condition if the calculated actual temperature (T.sub.act) exceeds the predefined temperature threshold (T.sub.th).

A miniature circuit breaker, a control method thereof, and a control system thereof, where the miniature circuit breaker includes a circuit breaker body and a current detection unit. The circuit breaker body and the current detection unit are located in respectively independent cavities in the circuit breaker and are electrically coupled to each other. After a current that flows from one end of the circuit breaker body flows through the current detection unit, the current flows into another end of the circuit breaker body. The current detection unit includes a voltage drop detection assembly and a signal output terminal. The voltage drop detection assembly includes a first voltage sampling point and a second voltage sampling point, where the first voltage sampling point and the second voltage sampling point are coupled to the signal output terminal.

An intelligent electronic device (IED) may provide point on wave switching. The IED may receive a control operation request, and determine when to issue a control command to cause a switch to change positions. The actuation of the switch may occur at a target point on an alternating current. An IED may have a processor that is too slow to implement a switch when a desired point on an alternating current first occurs. Accordingly, some embodiments may compensate for the processing speed of an IED by determining a number of processor cycles needed (in advance) to issue a control command so that the resulting action results in the desired point on wave open or close.

A disconnect switch blade electronic sensor assembly system for a disconnect switch including a sensor assembly directly attachable to a switch blade for detecting the switch blade position, acceleration vectors and angular velocity of the switch blade relative to a cooperating disconnect switch stationary break-jaw contact assembly using a self-contained array of on board sensors for detection to ensure that the switch blade is in full electrical and mechanical contact with the stationary contact assembly in a switch fully closed position switch and fully out of electrical and mechanical contact with the stationary contact assembly in a switch fully open position. The switch blade sensor assembly can include a visual indication component to provide visual indication on the sensor assembly of switch status relative to the break-jaw assembly which can be seen on the ground or may initiate a remote visual or other indication of such switch status.

An intelligent electronic device (IED) may provide point on wave switching. The IED may receive a control operation request, and determine when to issue a control command to cause a switch to change positions. The actuation of the switch may occur at a target point on an alternating current. An IED may have a processor that is too slow to implement a switch when a desired point on an alternating current first occurs. Accordingly, some embodiments may compensate for the processing speed of an IED by determining a number of processor cycles needed (in advance) to issue a control command so that the resulting action results in the desired point on wave open or close.

The present invention provides a fault monitoring system for detecting connectivity faults in a device control centre. The fault monitoring system comprising for the or each control section, at least a first pair of temperature sensors, one of the first pair of temperature sensors being adapted to detect the temperature of a of the first pair of terminals (T.sub.L1-IN), and the other of the first pair of temperature sensors being adapted to detect the temperature of the other of the first pair of terminals (T.sub.L1-OUT)The system comprises a processor configured to receive the detected temperatures, calculate an IN-OUT difference the IN-OUT difference, being a difference between the temperatures of the first pair of terminals (T.sub.L1), compare the calculated IN-OUT difference with a predetermined threshold value (T*.sub.L1), whereby a calculated difference IN-OUT (T.sub.L1) greater than the predetermined threshold value (T*.sub.L1) is indicative of a connectivity fault at one of the first pair of terminals, and to generate at least one output signal based on the results of the comparison.

Switching device (1) for operating at least one load, comprising at least one switching unit (7; 8; 9), which switches a tapped current phase (L) to a load (2-1; 2-2; 2-3) connectable to the switching unit (7; 8; 9) to supply said load with current and which has a measurement unit (7C; 8C; 9C) which measures a current phase progression of the at least one current phase (L); a local control unit (18), which after receiving a control command from an external control system (24) actuates a semiconductor switch (7B; 8B; 9B) of the switching unit (7; 8; 9) in such a way that the semiconductor switch (7B; 8B; 9B) switches at a zero of the current phase (L) measured by the measurement unit (7C; 8C; 9C), and a local monitoring unit (20), which evaluates the current phase progression, measured by the measurement unit (7C; 8C; 9C), of the at least one current phase (L) to detect an operational deviation from a normal current supply to the associated load (2-1; 2-2; 2-3) connected to the switching unit (7; 8; 9), and reports any detected operational deviation.

A monitoring method for an electrical energy transfer device which has a first phase conductor and a second phase conductor, includes the following steps: a temperature of the first phase conductor is compared with the temperature of the second phase conductor and a signaling is performed if there is a deviation between the temperatures. The electrical energy transfer device is, for this purpose, equipped at the first phase conductor with a first temperature sensor and at the second phase conductor with a second temperature sensor.

Disclosed is a vacuum circuit breaker capable of measuring and monitoring the temperature of a specific point, the vacuum circuit breaker comprising a temperature detection sensor located adjacent to an electric conduction pole. The temperature detection sensor includes: a sensor body located adjacent to one side of a plate part of the electric conduction pole; a fixing terminal which can be brought into contact with a specific point of the electric conduction pole to measure the temperature of the specific point; and a connection line which is located inside an electric conduction pole terminal of the electric conduction pole, and has one end coupled to the sensor body and the other end coupled to the fixing terminal.