Methods and apparatus for reducing peak power consumption of a grid connected power plant having a plurality of wind turbines. In response to determining that a power production value of the power plant is below a power threshold, one method includes: after a first time delay of a first group of one or more wind turbines, control the first group to operate in a power saving mode for a predefined first power saving period; and after a first time delay of a second group of one or more other wind turbines, control the second group to operate in the power saving mode for a predefined second power saving period. The first time delay of the first group is less than the first time delay of the second group and the power saving mode inhibits a power consuming activity for the wind turbines operating in the power saving mode.

A system for maintaining buoyant, energy-capture devices in general relative position in water in the presence of surface waves allows heeling of the energy capture devices while preventing collision. The system includes a grid of structural members that resists compression while permitting limited relative surface displacement between the first and second energy-capture devices. The structural members may be partially compressible and provide a restoring force, and they may allow heeling. Electricity from wave energy capture devices is combined in a way that smoothes variations inherent in wave action. Electricity from wind energy capture devices is combined with energy from wave energy capture devices for transmission to shore.

Provided is a method of feeding electric reactive power using a wind farm comprising wind turbines. The wind farm feeds a wind farm active power output and the wind farm active power output includes individual plant active power outputs each generated by one of the wind turbines. The wind farm feeds a wind farm reactive power output into the electrical supply network and the wind farm reactive power output includes individual plant reactive power outputs each generated by one of the wind turbines. The method includes determining a total wind farm reactive power output to be fed in by the wind farm and calculating, for each wind turbine, an individual plant reactive power output to be generated. The individual plant reactive power output is determined depending on the individual plant active power output and depending on the wind farm reactive power output to be fed in.

A grid-forming wind turbine control method for a diode rectifier unit-based offshore wind power transmission system. A control system for controlling a grid-side converter has a three-layered structure, where a first layer is a combination of an active power controller and a reactive power controller; a second layer is a voltage controller; and a third layer is a current controller. The actual reactive power is represented by a per-unit value of a capacity of a corresponding wind turbine unit. The wind turbine units have the same reactive-power reference value, which is constant and does not change with time. The reactive power controllers of all wind turbine units have the same structure and parameters.

An automated system for mitigating risk from a wind turbine includes a plurality of optical imaging sensors. A controller receives and analyzes images from the optical imaging sensors to automatically send a signal to curtail operation of the wind turbine to a predetermined risk mitigating level when the controller determines from images received from the optical imaging sensors that an airborne animal is at risk from the wind turbine.

A floating power-generation group comprises a floating hub such as a spar buoy that is anchored to subsea foundations by anchor lines. Floating power producer units such as wind turbines are connected electrically and mechanically to the hub. The power producer units are each moored by mooring lines. At least one mooring line extends inwardly toward the hub to effect mechanical connection to the hub and at least one other mooring line extends outwardly toward a subsea foundation. The groups are combined as a set whose hubs are connected electrically to each other via subsea energy storage units. Anchor lines of different groups can share subsea foundations. The storage units comprise pumping machinery to expel water from an elongate storage volume and generating machinery to generate electricity from a flow of water entering the storage volume. The pumping machinery may be in deeper water than the generating machinery.

The present disclosure relates to a method of operating a wind turbine, a corresponding wind turbine, a method of controlling a wind farm and a corresponding wind farm. The method comprises the steps of: determining a target maximum active power to be fed by the wind turbine into a power grid, in particular into an electricity power grid; monitoring a current active power fed from the wind turbine into the power grid; determining a reference time period corresponding to the determined target maximum active power; deriving an average of the active power fed from the wind turbine into the power grid during the reference time period; comparing the average of the active power with the target maximum active power; and operating the wind turbine at a set operating point permitting active power above the target maximum active power in case the average of the active power is below the target maximum active power.

The present disclosure discloses an offshore wind farm low-frequency alternating-current uncontrolled rectification electric power transmission system, comprising an onshore converter station and an offshore alternating-current system. The offshore alternating-current system comprises wind turbine generators, alternating-current submarine cables, a confluence bus, and offshore booster stations; the onshore converter station comprises a wind field side alternating-current bus, an alternating-current system side alternating-current bus, an alternating-current filter, an energy dissipation device, a rectifier, and a converter; the rectifier is composed of a three-phase six-pulse uncontrolled rectifier bridge, and the converter may be an MMC or an LCC; the rated frequency of the offshore alternating-current system is selected to be close to 10 Hz.

A system and method are provided for controlling a wind turbine of a wind farm. Accordingly, a controller implements a first model to determine a modeled performance parameter for the first wind turbine. The modeled performance parameter is based, at least in part, on an operation of a designated grouping of wind turbines of the plurality of wind turbines, which is exclusive of the first wind turbine. The controller then determines a performance parameter differential for the first wind turbine at multiple sampling intervals. The performance parameter differential is indicative of a difference between the modeled performance parameter and a monitored performance parameter for the first wind turbine. A second model is implemented to determine a predicted performance parameter of the first wind turbine at each of a plurality of setpoint combinations based, at least in part, on the performance parameter differential the first wind turbine. A setpoint combination is then selected based on the predicted performance parameter and an operating state of the first wind turbine is changed based on the setpoint combination.

Embodiments herein describe operating wind turbines in an offshore park to provide auxiliary power to a local AC grid or to an onshore grid during a grid malfunction. In one embodiment, the offshore park is coupled via a HVDC link to an onshore grid. When the HVDC link is down, a substation in the park includes a backup generator for creating a weak grid for powering auxiliary systems in a pilot turbine. The wind turbines in the park can switch to an auxiliary control system help power the auxiliary systems in the substation and in other turbines. In another embodiment, the offshore park is AC coupled to an onshore grid using a transformer in the substation. The wind turbines can participate in a brown or black start following a grid fault by switching to operating using the auxiliary control system.