Digital isolator devices, and many other devices, have a maximum device junction temperature, which, if exceeded, may cause device failure and the integrity of the isolation is no longer guaranteed. The use of an electronic fuse, eFuse, arranged in series with the digital isolator, provides a protection scheme for the digital isolator in which current is limited by the eFuse when it is determined that the supply current of the digital isolator exceeds a predetermined threshold that would the cause junction temperature to increase above an absolute maximum rating. As such, the integrity of the digital isolator is preserved in the event of a system fault.

Digital isolator devices, and many other devices, have a maximum device junction temperature, which, if exceeded, may cause device failure and the integrity of the isolation is no longer guaranteed. The use of an electronic fuse, eFuse, arranged in series with the digital isolator, provides a protection scheme for the digital isolator in which current is limited by the eFuse when it is determined that the supply current of the digital isolator exceeds a predetermined threshold that would the cause junction temperature to increase above an absolute maximum rating. As such, the integrity of the digital isolator is preserved in the event of a system fault.

The present invention is applied to a power system of a power plant including a three-winding transformer, and relates to a double incoming breaker system, including: a plurality of main circuit breakers respectively connected one by one to the plurality of first non-safety class high voltage buses and the plurality of second non-safety class high voltage buses; a plurality of auxiliary circuit breakers, one of which is connected in series to one of the plurality of main circuit breakers; a first power source measurer installed to correspond to the main circuit breaker and measuring a power source level of a non-safety class high voltage bus applied to the main circuit breaker; a second power source measurer installed to correspond to the auxiliary circuit breaker and measuring a power source level at an installed first point thereof; and a controller that outputs a first open signal to the main circuit breaker when an abnormal situation of the non-safety class high voltage bus is checked through the power source level measured by the first power source measurer, and outputs a second open signal to the auxiliary circuit breaker when it is determined that the main circuit breaker fails through the power source level at the first point measured by the second power source measurer after outputting the first open signal.

The present invention is applied to a power system of a power plant including a three-winding transformer, and relates to a double incoming breaker system, including: a plurality of main circuit breakers respectively connected one by one to the plurality of first non-safety class high voltage buses and the plurality of second non-safety class high voltage buses; a plurality of auxiliary circuit breakers, one of which is connected in series to one of the plurality of main circuit breakers; a first power source measurer installed to correspond to the main circuit breaker and measuring a power source level of a non-safety class high voltage bus applied to the main circuit breaker; a second power source measurer installed to correspond to the auxiliary circuit breaker and measuring a power source level at an installed first point thereof; and a controller that outputs a first open signal to the main circuit breaker when an abnormal situation of the non-safety class high voltage bus is checked through the power source level measured by the first power source measurer, and outputs a second open signal to the auxiliary circuit breaker when it is determined that the main circuit breaker fails through the power source level at the first point measured by the second power source measurer after outputting the first open signal.

An intelligent electronic device (IED) may obtain a voltage measurement matrix based on an arrangement of a transformer in a power system. The TED may obtain a delta connection compensating angle based on the location of the circuit breaker and the transformer arrangement. The IED may obtain voltage measurements of the transformer. The TED may determine a residual flux value of the transformer based at least in part on the voltage measurements, the voltage measurement matrix and the delta connection compensating angle. The TED may send a signal to a circuit breaker of the transformer to connect the transformer to the power system based at least in part on the system voltage and residual flux value.

An intelligent electronic device (IED) may obtain a voltage measurement matrix based on an arrangement of a transformer in a power system. The TED may obtain a delta connection compensating angle based on the location of the circuit breaker and the transformer arrangement. The IED may obtain voltage measurements of the transformer. The TED may determine a residual flux value of the transformer based at least in part on the voltage measurements, the voltage measurement matrix and the delta connection compensating angle. The TED may send a signal to a circuit breaker of the transformer to connect the transformer to the power system based at least in part on the system voltage and residual flux value.

This disclosure describes techniques implemented at least in part by a fuse-monitoring device to detect when a fuse cutout in an electric power system opens to disconnect a device and/or a load from a power line, and provides an indication of a location of the opened fuse cutout to a utility provider. The fuse-monitoring device may be attached to a fuse holder of the fuse cutout, and may include a movement sensor that detects when the fuse holder swings open due to its fuse melting, or blowing. The fuse-monitoring device may send a notification to the utility provider indicating that the fuse holder has swung open. The fuse-monitoring device may include a GPS sensor to determine the location of the fuse cutout, and may also notify the utility provider of the location of the fuse cutout so a line crew can quickly locate the fuse cutout that requires maintenance.

This disclosure describes techniques implemented at least in part by a fuse-monitoring device to detect when a fuse cutout in an electric power system opens to disconnect a device and/or a load from a power line, and provides an indication of a location of the opened fuse cutout to a utility provider. The fuse-monitoring device may be attached to a fuse holder of the fuse cutout, and may include a movement sensor that detects when the fuse holder swings open due to its fuse melting, or blowing. The fuse-monitoring device may send a notification to the utility provider indicating that the fuse holder has swung open. The fuse-monitoring device may include a GPS sensor to determine the location of the fuse cutout, and may also notify the utility provider of the location of the fuse cutout so a line crew can quickly locate the fuse cutout that requires maintenance.

A fault handling system of a solid-state transformer, including a first power unit and a second power unit that are cascaded and connected is provided. The first power unit includes a first auxiliary supply, a first control module, and a first communication module. The first auxiliary supply and the first control module are both electrically connected to two ends of a first busbar capacitor. The first control module is configured to detect a voltage of the first busbar capacitor. The second power unit includes a second auxiliary supply and a second control module. The second auxiliary supply and the second control module are both electrically connected to two ends of a second busbar capacitor. The first communication module outputs fault information to the second control module when the first control module detects that the voltage of the first busbar capacitor is greater than a threshold.

A fault handling system of a solid-state transformer, including a first power unit and a second power unit that are cascaded and connected is provided. The first power unit includes a first auxiliary supply, a first control module, and a first communication module. The first auxiliary supply and the first control module are both electrically connected to two ends of a first busbar capacitor. The first control module is configured to detect a voltage of the first busbar capacitor. The second power unit includes a second auxiliary supply and a second control module. The second auxiliary supply and the second control module are both electrically connected to two ends of a second busbar capacitor. The first communication module outputs fault information to the second control module when the first control module detects that the voltage of the first busbar capacitor is greater than a threshold.