In bearing applications, the presence of stray and parasitic currents in combination with lubricants has been studied for almost a century found to cause fluting corrugation damages under high current densities. However, recent research suggested that at low densities (<1 mA/mm2) specific operating conditions, electrical discharges can substantially reduce life due formation white etching cr...

The present paper considers pitching wave energy converters (WECs) integrated in a floating platform, e.g., foundation for wind turbine. Each WEC consists of partially submerged absorber that rotates about the hinge located above still water level under influence waves. contains separated ballast tanks are used to ensure desired initial tilting angle with respect (called rest angle). same can b...

Wave power is a potential technology for generating sustainable renewable energy. Several types of wave energy converters (WECs) have been proposed this purpose. WECs operate in harsh maritime environment that sets strict limitations on how and when the device can be economically safely reached maintenance. Thus, to ensure profitable generation over system life cycle, reliability key aspect con...

The diagnosis of wind energy conversion systems (WECS) turns out to be necessary because their relatively high cost operation and maintenance. Wind turbines are hard-to-access structures, they often located in remote areas. Therefore, a (e-diagnosis) is required. This paper proposes an alternative approach for the e-diagnosis WECS based on discrete wavelet transform (DWT) frequency analysis aer...

In recent years, we have been witnessing great interest and activity in the field of wave energy converters’ (WECs) development, striving for competitiveness economic viability via increasing power conversion while decreasing costs ensuring survivability [...]

This work presents the theoretical and practical comparison of linear nonlinear control laws for direct power a grid-connected double fed induction generator (DFIG), based wind energy conversion system (WECS) under different operating modes. We will show improvement brought by super twisting high order sliding mode to mitigate chattering phenomenon, due switching frequency. It also avoid hyperl...

In this paper, modeling of doubly fed induction generator (DFIG) based wind energy conversion system (WECS) and speed controller are presented. The System Identification Toolbox MatLab is used to develop the linear model WECS by considering as input output. Two models, namely Auto Regressive with eXogenous Input (ARX) Auto-Regressive Moving Average (ARMAX), estimated. We ARX221 structure best f...