A method of detecting a serial arc fault in a DC-power circuit includes injecting an RF-signal with a narrow band-width into the DC-power circuit and measuring a response signal related to the injected RF-signal in the DC-power circuit. The method further includes determining a time derivative of the response signal, analyzing the time derivative, and signaling an occurrence of a serial arc fault in the power circuit based on the results of the analysis. A system for detecting an arc fault is configured to perform a method as described before.

In a method for monitoring a high-voltage DC transmission the following are predefined: an amperage threshold value for an amperage of the high-voltage DC transmission, at least one interval length for time intervals and, for each predefined interval length, a change threshold value for a change in the amperage averaged over time intervals of the interval length. The amperage for each terminal of the high-voltage DC transmission is determined, and a change in the amperage averaged over time intervals of the interval length is determined for each predefined interval length. A DC error is determined if the magnitude of the amperage of at least one terminal is greater than the amperage threshold value or if, for an interval length, the magnitude of the averaged change in the amperage of at least one terminal is greater than the change threshold value predefined for the interval length.

One general aspect includes methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for fault protection of a bidirectional wireless power transfer system. The method includes the actions of detecting, by control circuitry of a wireless power transfer device, a fault for the bidirectional wireless power transfer system. Identifying an operating personality of the wireless power transfer device and a hardware configuration of the wireless power transfer device. Identifying, in response to detecting the fault and based on the operating personality and the hardware configuration, protection operations for protecting the wireless power transfer device from the fault. Controlling operations of the wireless power transfer device according to the protection operations. Other implementations of this aspect include corresponding systems, circuitry, controllers, apparatus, and computer programs, configured to perform the actions of the methods, encoded on computer storage devices.

One general aspect includes methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for fault protection of a bidirectional wireless power transfer system. The method includes the actions of detecting, by control circuitry of a wireless power transfer device, a fault for the bidirectional wireless power transfer system. Identifying an operating personality of the wireless power transfer device and a hardware configuration of the wireless power transfer device. Identifying, in response to detecting the fault and based on the operating personality and the hardware configuration, protection operations for protecting the wireless power transfer device from the fault. Controlling operations of the wireless power transfer device according to the protection operations. Other implementations of this aspect include corresponding systems, circuitry, controllers, apparatus, and computer programs, configured to perform the actions of the methods, encoded on computer storage devices.

A system and method for mitigating overvoltage on a DC link of a power converter of an electrical power system connected to a power grid includes receiving a voltage feedback signal from the DC link for a predetermined time period. The method also includes determining a rate of change of the voltage feedback signal during the predetermined time period. Further, the method includes predicting a future voltage value on the DC link as a function of the voltage feedback signal and the rate of change of the voltage feedback signal. Moreover, the method includes controlling the electrical power system based on the future voltage value.

A system and method for mitigating overvoltage on a DC link of a power converter of an electrical power system connected to a power grid includes receiving a voltage feedback signal from the DC link for a predetermined time period. The method also includes determining a rate of change of the voltage feedback signal during the predetermined time period. Further, the method includes predicting a future voltage value on the DC link as a function of the voltage feedback signal and the rate of change of the voltage feedback signal. Moreover, the method includes controlling the electrical power system based on the future voltage value.

A method of detecting a serial arc fault in a DC-power circuit includes injecting an RF-signal with a narrow band-width into the DC-power circuit and measuring a response signal related to the injected RF-signal in the DC-power circuit. The method further includes determining a time derivative of the response signal, analyzing the time derivative, and signaling an occurrence of a serial arc fault in the power circuit based on the results of the analysis. A system for detecting an arc fault is configured to perform a method as described before.

The present disclosure relates to arc fault detection in an electrical switch apparatus. In aspects of the present disclosure, an arc fault electrical switch apparatus includes a conductive path, a switch configured to interrupt electrical current in the conductive path, a current sensor in electrical communication with the conductive path and configured to measure the electrical current to provide current measurements, and a controller. The controller is configured to execute instructions to sample the current measurements to provide current samples, computing an estimated signal-to-noise ratio of the electrical current based on at least a portion of the current samples, determine whether the signal-to-noise ratio is less than a predetermined threshold, and activate the switch to interrupt the electrical current in the conductive path, if the signal-to-noise ratio is less than the predetermined threshold.

The present disclosure relates to arc fault detection in an electrical switch apparatus. In aspects of the present disclosure, an arc fault electrical switch apparatus includes a conductive path, a switch configured to interrupt electrical current in the conductive path, a current sensor in electrical communication with the conductive path and configured to measure the electrical current to provide current measurements, and a controller. The controller is configured to execute instructions to sample the current measurements to provide current samples, computing an estimated signal-to-noise ratio of the electrical current based on at least a portion of the current samples, determine whether the signal-to-noise ratio is less than a predetermined threshold, and activate the switch to interrupt the electrical current in the conductive path, if the signal-to-noise ratio is less than the predetermined threshold.

A serial bus buffer circuit includes a master input-output terminal, a slave input-output terminal, a switched resistor circuit, and a switch control circuit. The switched resistor circuit is configured to provide a low impedance connection between the master input-output terminal and the slave input-output terminal. The switch control circuit is coupled to the switched resistor circuit, and is configured to enable the low impedance connection based on voltage at the master input-output terminal and voltage at the slave input-output terminal.