Method and device for monitoring operation of a switching device for controlled switching applications

A device for monitoring operation of a switching device in a power system, the device comprising:

• an input interface for obtaining a measurement of a voltage at a source side from a first measurement equipment connected to the device and a measurement of a voltage at a load side of a coupled load from a second measurement equipment connected to the device, wherein the coupled load comprises a plurality of windings, and a coupling between one of at least two phases of a winding of the plurality of windings and at least two windings of the plurality of windings;
• a calculator configured to determine:
• a gap voltage associated with an electrical switching of at least one or a plurality of poles of the switching device based on the measurement of the voltage at the source side and the measurement of the voltage at the load side;
• a monitor configured to:
• monitor whether the gap voltage for the at least one pole meets a gap voltage threshold based on whether the gap voltage is zero and at least one of the source voltage and the load voltage is non zero during operation of another pole of the plurality of poles of the switching device,
• determine an electrical switching instant for the at least one pole when the gap voltage for the at least one pole meets the threshold during operation of another pole of the plurality of poles of the switching device, and
• determine a mechanical operating time deviation for the at least one pole based on the electrical switching instant, wherein the mechanical operating time deviation is used for evaluating release instant of an output command for operating the at least one pole of the switching device at desired electrical switching instant;
• and
• an output interface for providing an output command to the switching device, the output command configured to operate the at least one pole of the switching device.

A method for monitoring operation of a switching device in a power system, the switching device comprising a plurality of poles connecting a coupled load to a power source, the method comprising:

• obtaining, by a device, a measurement of a voltage at a source side from a first measurement equipment connected to the device, and a measurement of a voltage at a load side from a second measurement equipment connected to the device, the coupled load comprising a plurality of windings, and a coupling between one of at least two phases of a winding of the plurality of windings and at least two windings of the plurality of windings;
• determining a line to line voltage of at least one pole of the plurality of poles of the switching device based on a line measurement associated with at least one winding of the plurality of windings of the coupled load;
• monitoring whether the line to line voltage for the at least one pole meets a line to line voltage threshold based on at least one of determining that the load voltage becomes non zero during a switch on operation of another pole of the plurality of poles and determining that the load voltage becomes zero during a switch off operation of another pole of the plurality of poles during operation of another pole of the plurality of poles of the switching device;
• determining an electrical switching instant for the at least one pole based on the line to line voltage for the at least one pole meeting the line to line voltage threshold during operation of another pole of the plurality of poles of the switching device;
• and
• determining a mechanical operating time deviation for the at least one pole based on the electrical switching instant, for evaluating release instant of an output command of the switching device for operating the at least one pole of the switching device at the electrical switching instant.