In this paper, multiple offshore wave energy converters with different output characteristics are connected to one power distribution substation. The connection between the power take-off of the different wave energy converters and the electrical power transmission system is presented in order to investigate whether multiple wave energy converters can augment energy yield and improve network integration capabilities. Moreover, the model of an array of wave energy converters is developed with the goal of analyzing the effects of the offshore wave farm on the electrical network to which it is connected. It is also developed to ensure that the electricity generated by the array is sufficiently controllable, and of a quality that can be integrate into the electricity supply network without unduly increasing the cost of connection, production or delivery.

In this paper, a 1.5 kW Interior Permanent Magnet Synchronous Generator (IPMSG) with a power conditioner for the grid integration of a variable-speed wind turbine is developed. The power-conditioning system consists of a series-type 12-pulse diode rectifier powered by a phase shifting transformer and then cascaded to a PWM voltage source inverter. The PWM inverter is utilized to supply sinusoidal currents to the utility line by controlling the active and reactive current components in the q-d rotating reference frame. While the q-axis active current of the PWM inverter is regulated to follow an optimized active current reference so as to track the maximum power of the wind turbine. The d-axis reactive current can be adjusted to control the reactive power and voltage. In order to track the maximum power of the wind turbine, the optimal active current reference is determined by using a simple MPPT algorithm which requires only three sensors. Moreover, the phase angle of the utility voltage is detected using a simple electronic circuit consisting of both a zero-crossing voltage detecting circuit and a counter circuit employed with a crystal oscillator. At the generator terminals, a passive filter is designed not only to decrease the harmonic voltages and currents observed at the terminals of the IPMSG but also to improve the generator efficiency. The laboratory results indicate that the losses in the IPMSG can be effectively reduced by setting a passive filter at the generator terminals.

This paper presents a new wind speed estimation method for a variable speed wind turbine system, where the theory of SVR (support vector regression) is applied. The turbine speed is controlled to capture the maximum power according to the optimal tip-speed ratio. The inputs of SVR estimator are the wind turbine power and the rotational speed. By off-line training, a specified function which relates the input with the output is obtained. Then, the wind speed is determined from this predicted off-line function and the instantaneous input. The simulation and experimental results have shown that the wind speed is estimated rapidly and accurately

This paper describes efficient video coding schemes based on arbitrary shaped-region motion estimation technique. The effect of the object based motion estimation on the video compression quality is introduced in this work. The approach is based on new arbitrary shaped-region motion estimation technique (ASRA). In the motion estimation process, the frames are segmented into moving regions and non-moving regions using four steps predictive procedure. To reduce the required operations for motion estimation, the searching technique will be performed for the moving regions only. Moreover, to ensure the robustness against the additive noise as well as reducing the computation time, the ASRA algorithm will be performed in the first level of the wavelet domain. It does not need to send any segmentation information to the decoder. The proposed video coding methods are applied on videos containing a variety of scenarios such as multiple objects undergoing occlusion, splitting, merging, entering and exiting, as well as a changing background. For all videos, the proposed approach displays higher Peak Signal to Noise Ratio (PSNR) compared to MPEG-4 methods, and provides comparable or better compression than most of the recent video coding techniques.