Abstract:
A system (100) for producing electrical power based on wind energy is disclosed, which system (100) is capable of predicting its power output. The system (100) comprises a set of wind turbine units (105), a first plurality of sensors (120) each of which is adapted to sense at least one wind characteristic at some of the wind turbine units (105), and a second plurality of sensors (130) remotely located with respect to the wind turbine units (105) and each of which sensors (130) is adapted to sense at least one wind characteristic. At least one wind characteristic is estimated at the wind turbines (105) not having one of the first plurality of sensors (120) based on sensing by the first plurality of sensors (120) and an estimate of changes in wind characteristic at wind turbine units (105) caused by presence of other wind turbine units (105). The magnitude of electrical power production by the set of wind turbine units (105) at least one predefined point in time in the future is predicted based on the estimated wind characteristics and sensed wind characteristics.
Abstract:
Connection schemes for offshore power generation with an internal collection grid include a power generation system (22) which includes a plurality of generator-rectifier subsystems (23). The scheme further includes a medium voltage DC (MVDC) collection network with positive pole cables (42) and negative pole cables (44) connected to the DC outputs of the generator-rectifier subsystems (23). At least one offshore substation (50) includes a positive bus bar (54) and a negative bus bar (56) correspondingly connected to the positive pole cables (42) and negative pole cables (44) of the MVDC collection network and a plurality of main DC-DC converters (58). Each main DC-DC converter (58) includes modules connected to the MVDC bus bars (54, 56) and each module has a positive and a negative output with the modules' outputs serially connected to one another. The schemes may also include a high voltage DC transmission system connected to the modules' outputs and at least one DC/AC converter at a substation.
Abstract:
Connection schemes for offshore power generation with an internal collection grid include a power generation system which includes a plurality of generator-rectifier subsystems. The scheme further includes a medium voltage DC (MVDC) collection network with positive pole cables and negative pole cables connected to the DC outputs of the generator-rectifier subsystems. At least one offshore substation includes a positive bus bar and a negative bus bar correspondingly connected to the positive pole cables and negative pole cables of the MVDC collection network and a plurality of main DC-DC converters. Each main DC-DC converter includes modules connected to the MVDC bus bars and each module has a positive and a negative output with the modules' outputs serially connected to one another. The schemes may also include a high voltage DC transmission system connected to the modules' outputs and at least one DC/AC converter at a substation.
Abstract:
The present invention relates to a ground fault handling device (GHR) that provides an interface between two power transmission sections of a power transmission and/or distribution system as well as to such a power transmission and/or distribution system (10). The system comprises a first and a second power transmission section (G, 12) and the ground fault handling device (GHR) for connecting the first section to the second section, where the second section (12) is of a first type including at least one underground power line and the first section (G) is of another type lacking underground power lines. The ground fault handling device comprises a first isolating transformer (ITl) having a first set of windings and a second set of windings, where the first set is coupled to the first section, the second set is coupled to the second section and the windings of the second set are solidly or resistively (R1, R3, R4, R5) grounded.