Transmission-line voltage measurements in a digital-electricity power system are validated by acquiring a series of transmission-line voltage measurements during a sample period when a transmitter-disconnect device is in a non-conducting state. A numerical analysis is performed to determine a point in time at which AC components in the transmission line have diminished and at which the primary change in the transmission-line voltage measurement values is due to DC decay. A receiver acquires a series of receiver-voltage measurements during the same sample period; and a numerical analysis is performed on the receiver-voltage measurements to determine the point in time at which the AC components have diminished and where the primary change in the transmission-line voltage measurement values is due to DC decay. The transmitter-disconnect device is then placed in a non-conducting state based on an evaluation of those measurements.

A method for automatically categorizing disturbances in an electrical system includes capturing at least one energy-related waveform using at least one intelligent electronic device in the electrical system, and processing electrical measurement data from, or derived from, the at least one energy-related waveform to identify disturbances in the electrical system. In response to identifying a disturbance in the electrical system, each sample of the at least one energy-related waveform associated with the identified disturbance is analyzed and categorized into one of a plurality of disturbance categories. The disturbance categories may include, for example, (a) voltage sags due to upline electrical system disturbances, (b) voltage sags due to downline electrical system faults, (c) voltage sags due to downline transformer and/or motor magnetization, and (d) voltage sags due to other downline disturbances.

An item of electrical equipment has a preprocessing device for digital measured values. The preprocessing device has an integrated circuit and an electronic memory chip that contains a configuration of a logic circuit. If a fault of the preprocessing device is identified, an operation of the preprocessing device is interrupted until the configuration of the logic circuit has been loaded from a configuration memory chip into the electronic memory chip. There is also described a method for rectifying device faults, such as by reloading a configuration of a logic circuit into an electronic memory chip of a preprocessing device.

Configurable binary circuits for use in electrical power systems may include an input/output port, a binary input subsystem for receiving a binary input signal, a binary output subsystem for transmitting a binary output signal, and a switch subsystem for selecting one of the binary input subsystem or the binary output subsystem for operation. Intelligent electronic devices (IEDs) and associated methods may include one or more configurable binary circuits.

A control unit for a battery system, comprising: a microcontroller configured to generate a first control signal; a monitoring unit configured to generate a fault signal indicative of the operational state of the microcontroller; a first signal source configured to generate a state signal indicative of a system state; a comparator circuit configured to generate an intermediate control signal based on a first control signal and a fault signal; the comparator circuit further comprising a comparator node, the comparator circuit configured to transmit the intermediate control signal to the comparator node; wherein the first signal source is connected to the comparator node to transmit the state signal to the comparator node; the comparator circuit further comprises a comparator connected to the comparator node and configured to generate a switch control signal based on a voltage on the comparator node and based on a threshold voltage.

A method for protecting a server from damage by a liquid leak from a liquid-cooling unit of the server is provided. The server further includes a liquid leak sensor unit, a programmable logic circuit, and a power supply unit that supplies main power and standby power for the server. When a liquid leak is detected, the liquid leak sensor unit generates a main-power-off signal to the programmable logic circuit that causes the power supply unit to stop outputting the main power accordingly. The liquid leak sensor unit sends a total-power-off signal to the power supply unit to stop supply of the standby power after the power supply unit has stopped outputting the main power.

A power management device and a management method thereof are provided. The power management device includes a switch, a detection circuit and a controller. The switch receives an external power. The detection circuit receives an internal power and at least one operation power. The detection circuit determines whether at least one of the internal power and the operation power is in a preset specification range or not to generate a protection activate signal. The controller sets a protection flag according to the protection activate signal, and generates a control signal according to the protection flag by executing an application program. The controller transmits the control signal to turn off the switch.

A control system and method for a group of interconnected feeders which enables fault location, isolation and service restoration without requiring each switch to have topology knowledge of devices in adjacent feeders. The method defines, for each switch, connectivity and X/Y directional information about its neighboring switches and propagates this information throughout each feeder. A leader device is also determined for each feeder. Information about topology of adjacent feeders is not needed by all devices. Only normally-open tie switches which define a boundary between two adjacent feeders have knowledge of the devices in both feeders. Switches which open during fault isolation automatically find open tie switches in a direction opposite the fault, and request service restoration downstream of the fault by providing power from an adjacent feeder. Leader devices ensure an overload condition is not created before initiating opening and closing operations of switches downstream of the fault.

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.

An intelligent power distribution device is provided, which includes a power distribution diagnosis module and a power distribution monitoring module. The power distribution monitoring module includes a power measuring and controlling instrument. The power measuring and controlling instrument is configured to connect to a power supply line to be protected, and measure power data of the power supply line. The power distribution diagnosis module is connected to the power measuring and controlling instrument, and is configured to analyze the power data uploaded by the power measuring and controlling instrument, and protect the power supply line when it is determined based on an analysis result that the power supply line requires protection. Based on the analysis result of the power data of the power supply line, the intelligent power distribution device can protect the power supply line precisely and accurately, thereby improving protection effect of the power supply line.