The Wells wind turbine, which is used in the oscillating water column wave energy device, is simple but has a low efficiency. It stalls in strong winds caused by large waves and has a subsequent slow recovery. Its close relationship with the vertical axis wind turbine is pointed out. A novel...

The European Wave Energy Pilot Plants currently under construction are utilising Wells air turbines to convert oscillating pneumatic energy within the converters to unidirectional energy of rotation for direct coupling to electrical generators. The Wells turbine has also been proposed for future...

This study analyzes the problem of the stalling behaviour in Wells turbines, one of the most widely used turbines in wave energy plants. For this purpose two different control strategies are presented and compared. In the first one, a rotational speed control system is employed to appropriately...

A realistic performance analysis of oscillating water column wave energy converters (WECs) addresses to a set of non-linear differential equations that need to be integrated in time, by using a stochastic approach, under the hypothesis of random wind-generated sea waves, for all the sea states...

Wind Energy Conversion System (WECS) based on Doubly Fed Induction Generator (DFIG) connected to the grid is subjected to high transient currents at rotor side and rise in DC-link voltage during voltage sag at stator/grid side. To secure power system operation wind turbines have to meet grid...

This paper presents a new control strategy for a small scale wind farm which is composed of both fixed and variable speed wind turbine generator systems. Fixed speed wind generators (FSWGs) are largely dependent on reactive power, so they require large reactive power when a short circuit fault...

The large-scale application of doubly-fed wind turbines has significantly changed the fault transient characteristics of power systems. However, the transient state of a doubly-fed induction generator (DFIG) under large disturbances is difficult to accurately evaluate. The main difficulty lies...

The doubly-fed induction generators (DFIGs) are widely applied for wind energy conversion. Their reliability models are important to risk analysis of wind power systems, which has not been fully investigated due to changing topology configuration and sensitive reliability data. In this paper,...

The interest towards generic models or sometimes also called standard models of wind turbine generators (WTGs) is significantly increasing. Mainly due to their improved power quality, better controllability and higher power extraction capability, variable-speed wind turbines driving a...

The modelling of wind turbines with doubly-fed induction generator (DFIG) requires consideration of overall aerodynamic, mechanic, electromagnetic and control aspects, even in the case of DFIG representation in steady-state conditions for energy production assessment. This paper firstly...