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...

Wells turbine is one of the technical systems allowing an efficient use of the power contained in oceans’ and seas’ waves with a relatively low investment level. It converts the pneumatic power of the air stream induced by an Oscillating Water Column into mechanical energy. The standard...

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...

We compare the complexity of human gait time series from healthy subjects under different conditions. Using the recently developed multiscale entropy algorithm, which provides a way to measure complexity over a range of scales, we observe that normal spontaneous walking has the highest...

Design and implementation are studied for a neural network-based predictive controller meant to govern the dynamics of non-linear processes. The advantages of using neural networks for modeling non-linear processes are shown together with the construction of neural predictors. The resulting...

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...

Wind energy is rapidly growing in recent years. Among different types of wind turbines, due to several advantages, permanent magnet synchronous generator (PMSG) is attractive concept. Since the penetration level of wind power in the grid is increased, therefore, wind power can influence to the...

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...