A method of monitoring joint and contact conditions in an automatic transfer switch includes: collecting electrical signals at a plurality of measurement locations associated with a plurality of power sources and a load over a predetermined period, the electrical signals including voltages and load current; obtaining deltas between source voltages and corresponding load voltage measured at the measurement locations over the predetermined period; comparing the deltas with thresholds obtained during healthy condition; determining that the deltas fall outside of the thresholds; and in response to determining that the deltas fall outside of the threshold, transmitting an alert to a user, the alert indicating a detection of one or more failure modes at the measurement locations.

A test mode signal is generated to include a test pattern and an error reporting sequence. The test mode signal is sent on link that includes one or more extension devices and two or more sublinks. The test mode signal is to be sent on a particular one of the sublinks and is to be used by a receiving device to identify errors on the particular sublink. The error reporting sequence is to be encoded with error information to describe error status of sublinks in the plurality of sublinks.

This disclosure relates to monitoring the condition of electrical/electronic switches over time by monitoring the impedance of the switch. The condition of switches can degrade as they age, which can reduce their performance and may ultimately lead to failure. In many applications, particularly high-voltage applications, the reliable operation of switches may be very important and failures can present a safety risk and cause costly unscheduled system downtime for repairs. It has been realised that as the condition of switches change, their impedance changes, so monitoring the impedance can give a good indication of the condition of the switch, enabling potential faults/failures to be identified early and acted upon pre-emptively.

A device for monitoring a power semiconductor switch includes a circuit section for applying to the power semiconductor switch an HF voltage having a frequency above a switching threshold of the power semiconductor switch, a shunt resistor for detecting an actual HF current resulting from application of the HF voltage to the power semiconductor switch, a monitoring circuit for comparing the actual HF current with an expected HF current that depends on a switching state of the power semiconductor switch when the HF voltage is applied to the power semiconductor switch, and a comparator for generating a power semiconductor status signal depending on a result of the comparison. A corresponding method for monitoring a power semiconductor switch of this type is also described.

A method of analysing an out of service circuit breaker comprising a contact arrangement and a control interface comprises the following steps: placing the circuit breaker out of service, connecting a measuring unit to the contact arrangement of the circuit breaker for collecting measurement data, providing a data collection unit for wireless communication with the measuring unit, establishing a common time reference for the measuring unit and the data collection unit, thereby obtaining time synchronization between the measuring unit and the data collection unit, operating the contact arrangement, preferably comprising a sequence of opening and closing the contact arrangement, collecting measurement data, such as voltage and current, by means of the measuring unit, wirelessly communicating the measurement data, preferably in time stamped packages, from the measuring unit to the data collection unit, and analysing the measurement data to determine the state of the tested circuit breaker.

A contact measurement system for measuring a parameter of a contact of a switchgear includes: a first device for measuring an electrical resistance of the contact and mapping the electrical resistance spatially and/or dynamically; a second device for measuring an axial force of the contact and to map the axial force spatially and/or dynamically as a measured axial force; and a third device for measuring a position of the contact. The contact measurement system determines a position-depending force characteristic based on the measured axial force of the contact and the position of the contact. The contact measurement system determines a status of the contact based on a combination of the position-depending force characteristic with the electrical resistance of the contact.

The application provides a gas density relay with online self-check function and its check method, including a gas density relay body, a first pressure sensor, a second pressure sensor, a temperature sensor, a gas chamber, a pressure regulating mechanism, an online check contact signal sampling unit and an intelligent control unit. The air path of the pressure regulating mechanism is connected to the gas pressure chamber and the second pressure sensor; Pressure rise and fall can be regulated through the pressure regulating mechanism to make the gas density relay body contact action. The contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit. The intelligent control unit detects the action value and/or return value of the contact signal of the gas density relay body according to the density value when the contact acts, and completes the check work without requiring maintainer to go to the site for check. At the same time, because the pressure regulating mechanism is not connected to the SF6 gas path of the gas density relay body or electrical equipment, its sealing requirements are reduced, the reliability of the power grid is improved, and the manufacturing cost is reduced.

A switching network includes a switch, a driver for the switch, and a floating-regulator that powers the driver. The floating-regulator includes a shunt that is used only when testing the network. The shunt diverts biasing current so that it does not interfere with a measurement of an electrical property of a switch.

An electromagnetic testing assembly to predict a usable life of an installed vacuum interrupter in the field, which can include an electromagnetic testing device connected to a flexible magnetic field coil to generate a potential in a vacuum interrupter in an installation, magnetically monitor ion flow across one or more gaps in the vacuum interrupter, and apply trend data, tube chart information, and an algorithm to predict the usable life.

A semiconductor module including a semiconductor element which is bonded to a wiring pattern part and connects or disconnects two main electrode terminals to or from each other according to a drive signal applied to a gate electrode terminal, includes a deterioration detecting circuit configured to use one main electrode terminal of the two main electrode terminals of the semiconductor element with an applied DC voltage, as a reference potential, and detect deterioration of a joining part of the semiconductor element on the basis of a gate voltage which is the voltage between the one main electrode terminal and the gate electrode terminal and an inter-main-electrode voltage which is the voltage between the one main electrode terminal and the other main electrode terminal, and outputs an alarm signal.