The present invention relates to a method and a monitoring system, for monitoring a vacuum on-load tap changer. The tap changer includes a housing with insulating fluid, a diverter switch inside of the housing and including at least one movable contact and at least two vacuum interrupters, and at least one pressure sensor which measures the pressure in the housing. The method, which is performed by a processing circuitry in the system, includes determining a pressure signature, including two succeeding peaks within a time interval, continuously measuring the pressure, detecting when the measured pressure shows the pressure signature, determining, based on the measured pressure within the pressure signature, the time between the first rise in pressure and the second drop, and setting the determined time to represent the switch time of the diverter switch.

The present invention relates to a method and a monitoring system, for monitoring a vacuum on-load tap changer. The tap changer includes a housing with insulating fluid, a diverter switch inside of the housing and including at least one movable contact and at least two vacuum interrupters, and at least one pressure sensor which measures the pressure in the housing. The method, which is performed by a processing circuitry in the system, includes determining a pressure signature, including two succeeding peaks within a time interval, continuously measuring the pressure, detecting when the measured pressure shows the pressure signature, determining, based on the measured pressure within the pressure signature, the time between the first rise in pressure and the second drop, and setting the determined time to represent the switch time of the diverter switch.

The invention relates to a system (30) and a method for identifying a non-switching semiconductor switch (34a, 36a). The system (30) comprises a first semiconductor switch (34a), a first semiconductor component (34b), a second semiconductor switch (36a), a second semiconductor component (36b), a first resistor (64b), a second resistor (66b) and a detection unit (38). The detection unit (38) is designed to identify, on the basis of a curve of a first voltage dropping across the first resistor (64b), whether the first semiconductor switch (34a) is not switching. The detection unit (38) is designed to identify, on the basis of a curve of a second voltage dropping across the second resistor (66b), whether the second semiconductor switch (36a) is not switching.

A switchgear system includes a switchgear frame and a truck carrying a circuit breaker, which includes a breaker housing, a fixed electrical contact and a movable electrical contact mounted within the breaker housing, an actuator piston connected to the movable electrical contact, and a drive assembly coupled to the actuator piston. A sensor circuit is mounted on the switchgear frame under the truck and aligned with the circuit breaker and configured to acquire displacement data of the actuator piston when in a contact testing position. A controller is coupled to the sensor circuit and configured to receive the displacement data and determine electrical contact erosion within the circuit breaker.

A testing system includes a truck carrying a circuit breaker, a fixed contact, and an actuator piston connected to a movable contact. A test platform supports the truck in a contact testing position and includes a sensor circuit mounted on the test platform and positioned under the truck and aligned with the circuit breaker when the truck is on the test platform in the contact testing position. The sensor circuit is configured to acquire displacement data of the actuator piston when the movable electrical contact is moved between the open and closed positions. A controller is coupled to the sensor circuit and configured to receive the displacement data and determine electrical contact erosion within the circuit breaker.

A synthetic test circuit, comprising: a device under test including a chain-link converter under test, comprising a plurality of test modules, each test module including module switches connected with an energy storage device; a terminal connected to the device under test; at least one injection circuit operably connected to the terminal, the injection circuit including a source, the source including a source chain-link converter, which includes a plurality of source modules, each source module including a plurality of module switches connected with at least one energy storage device; a controller being configured to operate each source module to selectively bypass the corresponding energy storage device and insert the corresponding energy storage device into the corresponding source chain-link converter so as to generate a voltage across the source chain-link converter and thereby operate the injection circuit to inject a current waveform and/or a voltage waveform into the chain-link converter under test.

A system for management of a circuit breaker counter according to an exemplary embodiment of the present invention includes a data processing unit receiving state change data and measurement data of at least one of a circuit breaker and a current measuring unit and transferring an event on the basis of the state change data and measurement data; and a counter managing unit counting a total operation, a load-breaking operation and a fault-breaking operation of the circuit breaker, based on the event and the measurement data, and outputting and storing respective count accumulation values.

A system for management of a circuit breaker counter according to an exemplary embodiment of the present invention includes a data processing unit receiving state change data and measurement data of at least one of a circuit breaker and a current measuring unit and transferring an event on the basis of the state change data and measurement data; and a counter managing unit counting a total operation, a load-breaking operation and a fault-breaking operation of the circuit breaker, based on the event and the measurement data, and outputting and storing respective count accumulation values.

A fault detector for an anti-parallel thyristor includes: a power supply unit configured to supply power to the first and second thyristors; a first current sensor configured to output a first current measurement value that flows through the first thyristor; a second current sensor configured to output a second current measurement value that flows through the second thyristor; and a detector which notifies a fault of a thyristor when the first and second current measurement values satisfy a set fault condition,

A switching device has a current transformer for measuring in a potential-free manner a current to be switched by the switching device, a current sense amplifier, to which the unrectified measurement current of the current transfer is fed on the input side, and a controller, to which the output current of the current sense amplifier is fed on the input side and which is configured so as to digitalize the fed output current and to perform one or more performance-related measurements and to output the measurement results.