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.

A power control apparatus has a switch configured to interrupt power supply from a system power when the switch has detected a drop of voltage from the system power below a threshold, a first power controller configured to receive a voltage drop signal supplied from the switch unit, a first power storage unit connected to the first power controller, a second power controller configured to receive a discharge start signal supplied from the first power controller, a second power storage unit connected to the second power controller, and a rotary machine generator that receives an operation control signal supplied from the second power controller or the second power storage unit.

A power supply system includes AC output converters that are connected in parallel and supply electric power to an AC load. Each of the AC output converters includes an AC-DC converter, a DC-AC converter that converts, a secondary battery, a first switching circuit provided between the AC load and the DC-AC converter, a bypass path, a second switching circuit provided between the AC load and the bypass path, a switch control circuit, and a control power supply circuit. The switch control circuit turns off the first switching circuit upon detection of a decrease in voltage supply from the secondary battery to the AC load during power failure of the external AC voltage, and turns on the second switching circuit upon detection of stop of voltage supply from all of the AC output converters to the AC load during power failure of the external AC voltage.

Provided is a method, device and system for outputting a controller setpoint for at least one power generator that is at least one wind power installation, at least one windfarm, or a cluster controller. The method includes receiving, over a data input, a data packet including a current setpoint and a plurality of future setpoints, storing the future setpoints of the received data packet in a memory, and outputting, over a data output, the current setpoint as the controller setpoint. If after the expiration of a predefined time period from the reception of the data packet, no further data packet is received, a first setpoint of the stored plurality of future setpoints is output over the data output as a next controller setpoint.

Embodiments of this application provide an energy storage system and a black start method. The energy storage system includes a black start controller, a battery module, a first converter, and a system control unit. The black start controller outputs a black start signal, the battery module generates an output voltage based on the black start signal, and the first converter supplies power to the system control unit based on the black start signal and the output voltage of the battery module, to enable the system control unit to implement black start of the energy storage system based on the black start signal.

A wind power generation system includes a power generator body, an auxiliary device that assists the power generator body, and a power conversion apparatus that converts first AC power generated by the power generator body to second AC power, and outputs the second AC power to an electric power grid. The power conversion apparatus includes a first power conversion circuit, a second power conversion circuit, a power storage element that receives DC power from the first power conversion circuit via a first passing point, a breaker, and a control unit. When the power generator body is in a power generation standby state, the control unit sets a parallel-off mode and controls the second power conversion circuit to convert power of the power storage element to third AC power having a preset voltage. The auxiliary device is configured to receive the second AC power or the third AC power.

A management device is connected to an AC power line provided with a plurality of connection ports, each of which can be connected to an electric device including a power storage unit. The management device includes a measurement unit configured to measure an electric signal on the AC power line, a determination unit configured to determine a type of the electric device connected to the AC power line via a connection port in the plurality of connection ports based on a measurement result of the measurement unit, and a first prediction unit configured to predict an amount of power supply on the AC power line due to discharge of the power storage unit based on a determination result of the determination unit.

A power management server comprises a controller configured to select, from a plurality of facilities having storage battery apparatuses, two or more first facilities applying first processing configured to suppress a discharge amount of the storage battery apparatuses. The controller is configured to apply, to the two or more first facilities, a same condition as a suppression condition of the discharge amount of the storage battery apparatuses.

A power management server comprises a controller configured to select, from a plurality of facilities having storage battery apparatuses, two or more first facilities applying first processing configured to suppress a discharge amount of the storage battery apparatuses. The controller is configured to apply, to the two or more first facilities, a same condition as a suppression condition of the discharge amount of the storage battery apparatuses.

Harmonics of a power output of a power plant at a point of common coupling between the power plant and a utility grid, wherein the power plant comprises a plurality of energy production units. The method comprises determining an electrical characteristic at the point of common coupling; determining the electrical characteristic at an output terminal of each of the energy production units and dispatching a control signal to at least one of the energy production units to control the electrical characteristic at an output terminal of the respective energy production units. The control signal is based on the measurement of the electrical characteristic at the point of common coupling and arranged for damping the harmonic of the power output of the power plant at the point of common coupling, wherein the control signal is determined on the basis of a predetermined prioritizing sequence of said electrical characteristic.