Abstract
The rapid growth of wind power generation and the need for a smarter electrical grid with a decentralized energy generation, especially in the urban areas, has increased the interest in vertical axis wind turbines (VAWT). The Darrieus type VAWT performance prediction is a very complex task, since its blades move around the rotor axis in a three dimensional aerodynamic environment that leads to several flow phenomena, such as, dynamic stall, flow separation, flow wake deformations and their natural inability to self-start. In the lift-type turbines the self-start incapability can be overcome with the use of several more or less complex solutions, being one of them the development of a blade profile capable of making the wind turbines self-start. Hence, this paper focuses on presenting a new methodology for fast development of new blade profiles, for self-start capable Darrieus type VAWT. © 2011 IEEE.

Abstract
This paper is on the short-term hydro scheduling (STHS) problem, particularly concerning a head-dependent cascaded hydro system. A mixed-integer quadratic programming approach is proposed for the STHS problem, considering not only head-dependency, but also discontinuous operating regions and discharge ramping constraints. Moreover, market uncertainty is introduced in the model via price scenarios, and risk-aversion is considered by limiting the volatility of the expected profit. Numerical results, based on one of the main Portuguese cascaded hydro systems, illustrate the proficiency of the proposed approach. Finally, conclusions are duly drawn. © 2011 IEEE.

Abstract
This paper is concerned with the harmonic behavior of variable-speed wind turbines during a control fault. Different topologies for the power-electronic converters are considered, namely two-level and multilevel converters. A three-mass drive train model is considered, and a fractional-order control strategy is proposed for the wind turbines. The performance of disturbance attenuation and system robustness is ascertained. Finally, conclusions are duly drawn. © 2011 IEEE.

Abstract
This paper is on variable-speed wind turbines with permanent magnet generator. A three-mass drive train model and two different topologies for the power-electronic converters are considered. The two different topologies considered are respectively a matrix and a multilevel converter. A control strategy, based on fractional-order controllers, is proposed for the wind turbines. Previous papers were mainly focused on the transient stability of variable-speed wind turbines at external grid faults. Instead, this paper considers the possibility of an internal abnormal operating condition, namely a converter control malfunction. The influence of the converter control malfunction on the harmonic current emissions is studied. Comprehensive results are presented, and conclusions are duly drawn. © 2011 IEEE.

Abstract
This paper is on variable-speed wind turbines with permanent magnet synchronous generator (PMSG). A three-mass drive train model and two different topologies for the power-electronic converters are considered. The two topologies considered are a matrix and a multilevel converter. A fractional-order control strategy is proposed for the wind turbines. Computer simulation results are presented to illustrate the behavior of the wind turbines during a converter control malfunction. Finally, conclusions are duly drawn. © 2011 IEEE.

Abstract
This paper is on wind energy conversion systems with full-power converter and permanent magnet synchronous generator. Different topologies for the power-electronic converters are considered, namely matrix and multilevel converters. Also, a new fractional-order control strategy is proposed for the variable-speed operation of the wind turbines. Simulation studies are carried out in order to adequately assess the quality of the energy injected into the electric grid. Conclusions are duly drawn. ©2010 IEEE.