Wind inflow observation from load harmonics

Influence of load changes on tricuspid inflow.

In healthy subjects, the right ventricular filling pattern estimated from tricuspid valve inflow is highly load-dependent. This can be clearly demonstrated by changes of Doppler inflow tracings recorded during tidal breathing at rest. The aim of our study was to test the magnitude of tricuspid inflow changes during more pronounced load changes induced by specific maneuvers. In 31 apparently hea...

Harmonics in a Wind Power Plant: Preprint

Reliability Assessment of Distribution Transformers Considering Load Harmonics

The progressive application of non-linear loads in distribution systems (DS) increases current harmonics flow in DS's apparatuses, especially distribution transformers (DTs). Since DTs' operating temperature rises due to the harmonics flow, their loading should be reduced such that the hot spot temperature (HST) is preserved under its permissible value. This means that DTs' available capacity i...

Individual pitch control of wind turbines using local inflow measurements

This paper describes a model based control approach for individually adjusting the pitch of wind turbine blades and thereby attenuating the effect of asymmetric wind loads. It is assumed that measurements of local inflow along each blade are available. This effectively provides an estimate of the load distribution along the blades. The load estimates are used in a predictive setup where inflow ...

Measured wind turbine loads and their dependence on inflow parameters

The Long-Term Inflow and Structural Test (LIST) program is gathering inflow and structural response data on a Westinghouse 600-kW wind turbine located at a test site near Boulder, Colorado. Data from 1043 ten-minute time segments are analyzed here to determine the dependency of fatigue and extreme loads on inflow parameters. Flap and edge bending moment ranges at the blade root are studied as t...