A system is provided that includes a power transmitter configured to provide power to a current loop, a power receiver configured to receive the power from the current loop. The power receiver is configured to, on a periodic basis, disconnect from the current loop to stop pulling power from the current loop for a period of time to enable a safety check to be performed by the power transmitter. The power transmitter is configured to: monitor current on the current loop; determine whether a current level on the current loop passes the safety check within a predetermined time interval since a determination that the current level was not within a safe range; and control connectivity of the power to the current loop depending on whether the safety check has or has not passed within the predetermined time interval.

The present disclosure relates to a recloser control that monitors compliance of a standard for distributed energy resources (DERs). For example, a method includes obtaining power system measurements between a microgrid and an area electronic power system (EPS). The method includes determining a rate of change of power (RoCoP) based on the power system measurements. The method includes determining that a DER exceeded a threshold of the area EPS based at least in part on the RoCoP. The method includes sending a signal indicating that the DER has violated the threshold.

A phase shifter includes a signal input, a signal output, an ESD protection circuit, first and second signal paths between the signal input and the signal output. The ESD protection circuit includes first and second two port devices, each two port device being switchable between a high impedance state and a low impedance state. The first signal path includes the first two port device of the ESD protection circuit and a first delay line configured to provide a first phase shift to a signal transmitted from the signal input to the signal output via the first signal path. The second signal path includes the second two port device of the ESD protection circuit and a second delay line configured to provide a second phase shift, different from the first phase shift, to the signal transmitted from the signal input to the signal output via the second signal path.

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 invention relates to an elevator comprising at least one elevator car moved by at least one elevator motor, which elevator motor is driven by a frequency converter controlled by a control device of the elevator, the frequency converter comprising a rectifier bridge, an inverter bridge and a DC link connected in-between, the inverter bridge being connected to the elevator motor and the rectifier bridge being connected to AC mains via three phase supply lines comprising an LCL-filter and a mains switch. The elevator further comprises a backup power supply and a safety device of the control device, which in case of a mains power failure is configured to switch off the mains switch and to connect the backup power supply to the DC link and/or to at least one phase supply line, whereby the rectifier bridge is a bidirectional rectifier bridge being configured to convert DC supplied to the DC link from the backup power supply to an AC voltage supplied to at least two of the phase supply lines connected with at least one load circuit. An earth fault protection circuit for the load circuit is connected between earth and a common terminal of the capacitors of the LCL filter for monitoring an earth fault indicating signal, and which earth fault protection circuit is configured to issue an earth fault signal and/or initiating earth fault safety measures, dependent on the earth fault indicating signal.

An electrical device includes a first terminal structured to electrically connect to a power source; a second terminal structured to electrically connect to a load; a voltage sensor electrically connected to a point between the first and second terminals and being structured to sense a voltage at the point between the first and second terminals; a switch electrically connected between the first terminal and the second terminal; and a control unit structured to detect a power quality event in the power flowing between the first and second terminals based on the sensed voltage and to control a state of the switch based on the detected power quality event.

The present specification provides a method and device for determining a disturbance condition in a power transmission line. The method includes obtaining (302) a plurality of sample values corresponding to an electrical parameter measured in each phase. The method further includes determining (304) a plurality of magnitudes of the electrical parameter corresponding to each phase based on the corresponding plurality of sample values and determining (306) a plurality of difference values for each phase based on the corresponding plurality of magnitudes. The method includes processing (308) the plurality of difference values using a machine learning technique to determine the disturbance condition. The disturbance condition is one of a load change condition, a power swing condition and an electrical fault condition. The method also includes performing (310) at least one of a protection function and a control function based on the disturbance condition.

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.

Provided is a method for monitoring DC electrical power. The method including determining a rate of change of the DC electrical power, determining whether the rate of change of the DC electrical power is greater than a predetermined threshold, when the rate of change of the DC electrical power is greater than the predetermined threshold, determining whether the rate of change of the DC electrical power is greater than the predetermined threshold for a predetermined period of time, and when the rate of change of the DC electrical power is greater than the predetermined threshold for the predetermined period of time, sending a signal indicating an interruption in the DC electrical power.