Solar electron beams responsible for type III radio emission generate Langmuir waves as they propagate out from the Sun. The Langmuir waves are observed via in-situ electric field measurements. These Langmuir waves are not smoothly distributed but occur in discrete clumps, commonly attributed to the turbulent nature of the solar wind electron density. Exactly how the density turbulence modulate...

A specific feature of wind power generation is the stochastic behavior of wind velocity what determines the energy produced, and also influences the turbine degradation process due to the stochastic load suffered by the wind turbine. Thus, wind turbines present a degradation process more complex than the equipment that work under stationary conditions.The selection of maintenance strategy, that...

Netherlands Received ; accepted – 2 – ABSTRACT Axisymmetric stellar wind solutions are presented, obtained by numerically solving the ideal magnetohydrodynamic (MHD) equations. Stationary solutions are critically analysed using the knowledge of the flux functions. These flux functions enter in the general variational principle governing all axisymmetric stationary ideal MHD equilibria. The magn...

Data collected from the supervisory control and data acquisition (SCADA) system, used widely in wind farms to obtain operational and condition information about wind turbines (WTs), is of important significance for anomaly detection in wind turbines. The paper presents a novel model for wind turbine anomaly detection mainly based on SCADA data and a back-propagation neural network (BPNN) for au...

In this paper, the different parameter estimation methods such as maximum likelihood method, least square method, weighted least square method, moments method, the method based on quantiles and maximum spacing method for the Weibull distribution which are widely accepted in wind power studies are presented and discussed. The effect of the selecting parameter estimation method on the estimation ...

The risk associated with introducing wind turbines into the generation fleet is investigated in this paper. The loss of load probability (LOLP) and statistical expected demand not supplied (EDNS) are adopted as the risk indices. A case study is reported to evaluate the risk posed by displacing conventional generation with wind turbines. Results on the test system show that multiples of wind tur...

By utilizing condition monitoring information collected from wind turbine components, condition based maintenance (CBM) strategy can be used to reduce the operation and maintenance costs of wind power generation systems. The existing CBM methods for wind power generation systems deal with wind turbine components separately, that is, maintenance decisions are made on individual components, rathe...

A theoretical model that describes the power of a scattered Global Positioning System (GPS) signal as a function of geometrical and environmental parameters has been developed. This model is based on a bistatic radar equation derived using the geometric optics limit of the Kirchhoff approximation. The waveform (i.e., the time-delayed power obtained in the delay-mapping technique) depends on a w...