Wind power analysis and site matching of wind turbine generators in Kingdom of Bahrain

In this paper, the hourly measured wind speed data for years 2003–2005 at 10 m, 30 m and 60 m height for Kingdom of Bahrain have been statically analyzed to determine the potential of wind power generation. Extrapolation of the 10 m data, using the Power Law, has been used to determine the wind data at heights of 30 m and 60 m. Weibull distribution parameters have been estimated and compared annually and on monthly bases using two methods; the graphical method and the another method, designated in this paper as approximated method, which depends on the standard deviation and average wind speed. The maximum power density for 10 m, 30 m and 60 m heights were found to be 164.33 W/m², 624.17 W/m² and 1171.18 W/m² in February, respectively while the minimum power density were 65.33 W/m², 244.33 W/m² and 454.53 W/m² in October, respectively. The average annual wind power density was found to be 114.54 W/m² for 10 m height, 433.29 W/m² for 30 m height and 816.70 W/m² for 60 m height. Weibull probability function, using Weibull parameters estimated from the approximated method, has shown to provide more accurate prediction of average wind speed and average power density than the graphical method. In addition, the site matching of wind turbine generators at 30 m and 60 m heights has been investigated by estimating the capacity factors of various commercially available wind turbines generators. The monthly and annual variation of capacity factors have been studied to ensure optimum selection of wind turbine generators.     

Design and analysis of dynamic voltage restorer for deep voltage sag and harmonic compensation

A dynamic voltage restorer (DVR) to compensate deep voltage sags and harmonics is proposed. The DVR consists of shunt and series converters connected back-to-back through a DC-to-DC step up converter. The presence of the DC-to-DC step converter permits the DVR to compensate deep voltage sags for long duration. The series converter is connected to the supply side whereas the shunt converter is connected to the load side. With this configuration, there is no need for large DC capacitors. A design procedure for the components of the DVR is presented under a voltage sag condition. The control system of the proposed DVR is based on hysteresis voltage control. Besides voltage sag compensation, the capability of compensating load voltage harmonics has been added to the DVR to increase the power quality benefits to the load with almost negligible effect on the sag compensation capability. The proposed DVR is modelled and simulated using SIMULINK/MATLAB environment. Time domain simulations are used to verify the operation of the DVR with linear and non-linear loads.     

VSC-HVDC station with SSSC characteristics

Commercial installations of voltage-source converter-high voltage direct current (VSC-HVDC) are now in service as asynchronous link and as underwater/underground dc transmission. The research reported in this paper is directed to providing VSC-HVDC with synchronizing power and damping power so that after a transient, the steady-state is reached in minimal time. Damping power is achieved by injecting incremental power which is proportional to the frequency deviation measured by a phase lock loop. Synchronizing power is achieved by: 1) introducing a delay in the power measurement and 2) by incorporating a static synchronous series compensation in the VSC-station. The effectiveness of both the synchronizing and damping power is demonstrated through digital simulations of a turbine-generator system which is connected to a VSC-HVDC Station. It is shown that with the synchronizing power and damping power, recovery from the fault disturbance is very much faster.