A power failure detection system according to the present disclosure includes an optical fiber (10) configured to detect a state of a transformer (40), a reception unit (201) configured to receive an optical signal including information indicating the state of the transformer (40), from the optical fiber (10), and a detection unit (202) configured to detect occurrence of a power failure, based on information indicating the state of the transformer (40), the information being included in the optical signal.

A method for controlling a wind farm, which is operated by means of a wind farm control unit and comprises a multiplicity of wind power installations having wind power installation controllers and being connected to one another via a common wind farm grid, which is connected to an electrical power supply grid of a grid operator by means of a wind farm transformer, comprising the following steps: reception of at least one fault bit at the wind farm control unit, in particular at least one fault bit of the grid operator, deactivation of all external setpoint value specifications at the wind farm control unit apart from those of the grid operator after reception of the fault bit, activation of a closed-loop fault case control implemented in the wind farm control unit after successful deactivation of all external setpoint value specifications apart from those of the grid operator.

A method for intelligent fault detection and location of a power distribution network is provided, which includes: constructing a network topology of the power distribution network, updating the network topology in real time to obtain an updated network topology, performing a fault identification based on the updated network topology, performing a fault locating based on the updated network topology to determine a fault node, and identifying a fault type based on a fault recorded signal of the fault node. With this method, fault locations and fault types of the power distribution network can be accurately detected in real time.

Methods and systems for identifying and correcting abnormal electrical activity about a structure are provided. An electricity monitoring device may monitor electrical activity including transmission of electricity via an electrical distribution board to devices about the structure. Electrical activity may be correlated with respective electrical devices to build an electrical profile indicative of the structure's electricity usage. Based on the electrical profile, abnormal electrical activity may be identified and corrective actions may be taken to mitigate or prevent structural damage.

A system and method for protection of an electrical grid. A respective one of the substations of the system including: a first directional protective relay to generate a signal operating on the electrical power line between the respective one of the substations and a remote one of the substations; a cyber health module to receive remote signals from two remote directional protective relays and output a reliability signal based on consistency of the remote signals and a status of the communication channels being operational; a circuit breaker to interrupt electrical power flow when directed; and a comparison circuit to receive signals and to direct the circuit breaker to interrupt electrical power flow when the reliability signal from the cyber health module indicates consistency, the first directional protective relay indicates fault, and at least one of the remote directional protective relays indicate fault.

A method for operating a wind turbine generator connected to a power network to account for recurring voltage faults on the power network caused by automatic reclosure of at least one circuit breaker following a short-circuit. The method comprises: identifying a deviation of voltage level of the power network from a normal operational voltage level of the network; determining that the identified deviation fulfils criteria for automatic reclosure; and operating the wind turbine generator in a recurring fault mode if automatic reclosure criteria are fulfilled. When operating the wind turbine generator in recurring fault mode, the method comprises: monitoring the recovery of the voltage level from the deviation; categorising the recovery of the voltage as one of at least a strong recovery or a weak recovery; and implementing a ride-through protocol according to the category of recovery.

Systems and methods for managing reactive power during low voltage ride through are provided. Responsive to detecting a fault on a power grid, a controller may identify a power regulation mode of the generator system. The controller can switch the power regulation mode to an offset power regulation mode of the generator system responsive to identifying the power regulation mode. The controller may adjust a value of a parameter of the generator system from a normal value to an offset value, wherein the parameter is selected based on the offset power regulation mode. The controller can maintain the value of the parameter as the offset value for a period of time. After the period of time, the controller can modify the value of the parameter from the offset value to the normal value, and the power regulation mode from the offset power regulation mode to the identified power regulation mode.

A method and a system for switching from grid-connected to grid-disconnected, and a power conversion system are provided. The method includes determining whether a power grid is abnormal based on a power grid parameter obtained when a PCS is grid-connected and operates in a current source mode, turning off a switching cabinet if the power grid is abnormal, switching from a current source mode to a voltage source mode, sending a command to instruct a grid-connected/grid-disconnected switch to switch from a grid-connected loop to a grid-disconnected loop, controlling an output parameter to smoothly transit from an abnormal parameter value recorded when the power grid is abnormal to a rated parameter value, and supplying power to a load according to the rated parameter value. In this way, seamless switching from grid-connected to grid-disconnected can be achieved, thereby ensuring stability of power supply.

An electronic device includes a power supply unit and a main body unit. The power supply unit converts electric power supplied from an external power supply to a DC voltage of a first voltage value to output the voltage to the main body unit and changes, in a case where power supply from the external power supply has been cut off, a value of the DC voltage that it outputs to a second voltage value that is different from the first voltage value. The main body unit executes predetermined termination processing in a case where the value of the DC voltage output by the power supply unit has changed to the second voltage value.

A technique enables microgrid switchover using zero cross detection. A flexible load management system includes a virtual critical load panel (vCLP) that utilizes circuit breakers in combination with companion modules configured to sense power provided to one or more loads to identify zero-crossings. When a preconfigured number of consecutive, missed zero-crossings is detected, the companion module is alerted as to potential main power loss and transitions to a virtual critical load (vCL) mode for load adjustment prior to operation under local power. Upon detection of main power loss, the companion module is configured for load activation (or deactivation) via states of one or more vCL bits that configure each load for either ON or OFF state when operating under local power.