Assessment of wind energy potential based on Weibull and Rayleigh distribution models

This article examines and evaluates the potential of solar and wind energy resources in the southern part of Uzbekistan, Bukhara region. It also analyzes the cost and negative impacts of the region’s electricity consumption and emission of atmospheric greenhouse gases over the years. According to the results of the study, the greenhouse gas emissions from the Bukhara region are estimated at 74.8 million tons as of 2018 and annual electricity consumption is 3.4 billion kW h. The gross (theoretical), technical and economic potential of the region’s wind energy was estimated using the Rayleigh distribution function at different seasons and at different heights. According to analysis, the region’s total wind energy capacity is 4606 billion kW h/year at 100 m in spring, 6848 billion kW h/year in summer, 3799 billion kW h/year in autumn, 4778 billion kW h/year in winter. In order to see the effective use of wind energy the wind turbidity diagram (wind rose) of the region has been identified and analyzed for different seasons. Solar energy was evaluated as the most efficient in the region and it is estimated that the solar photovoltaic potential of the region was 41 TWh/year, and produced by solar collectors was 184 TWh/year. According to the research conducted, the renewable energy sources such as solar and wind energy in the Bukhara region can provide consumers with full electricity supply and environmental, social, economic problems, energy security, reliability and continuity can be eliminated.

Opportunities and Prospects for the Using Renewable Energy Sources in Bukhara Region

Increasing Energy Efficiency and Reliability of Electric Supply of Low Power Consumers

A thin-walled shell and a thick-walled mass (cylinder) in contact with it, made of a different material, are structural elements of many machines, apparatus, and structures. The paper considers forced steady-state vibrations of cylindrical shell structures filled with a layered viscoelastic material. The study aims to determine the damping properties of vibrations of a structurally inhomogeneous cylindrical mechanical system under the influence of harmonic loads. The dynamic stress-strain state of a three-layer cylindrical shell filled with a viscoelastic material under the action of internal time-harmonic pressure is investigated. The oscillatory processes of the filler and the bonded shell satisfy the Lame equations. At the contact between the shell and the filler, the rigid contact conditions are satisfied. Dependences between stresses and strains for a linear viscoelastic material are presented in the form of the Boltzmann-Voltaire integral. The method of separation of variables, the method of the theory of potential functions (special functions), and the Gauss method are used to solve this problem. Based on the analysis of the numerical results, it was found that the dependence of the resonant amplitude of the shell displacements on the viscous properties of the filler is 12-15%. Analysis of the results obtained shows that the study of vibrations of shells containing fillers according to the rod theory will lead to rather large erroneous results (up to 20%).

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Vibrations of Cylindrical Shell Structures Filled With Layered Viscoelastic Material

A comparative study of five numerical methods for the estimation of Weibull parameters for wind energy evaluation at Eastern Jerusalem, Palestine

With the development of small business in Uzbekistan’s rural areas, there is a shortage of electric power, as well as power outages for these consumers. The use of renewable energy sources is one way to solve this problem, and this has been little studied in Bukhara oblast. A preliminary study of this problem shows that the region has the necessary capacity of renewable energy sources. This paper presents the results of a study of wind speed and wind energy potential in Bukhara oblast located in southwestern Uzbekistan. The data of wind speed and direction measured at the weather station at Bukhara’s international airport, taken at an altitude of 10 meters, were analyzed on the basis of the two-parameter Weibull distribution function. The main parameters k and c of the Weibull distribution function were determined using the empirical method. Wind speed and direction were statistically analyzed in MatLab and a graph (wind rose) was plotted. Wind energy potentials at different altitudes were also evaluated.

Statistical Analysis of Wind Energy Potential in Uzbekistan’s Bukhara Region Using Weibull Distribution

This article provides information on the current state and prospects for the development of renewable energy sources in the world and in our country, as well as on the choice of efficient power generators to ensure stable operation at low flows of micro hydroelectric and wind power plants. When designing a simulation model and a theoretical study of the dynamic modes of an electric generator, Solidworks and Matlab/Simulink software were used. Mathematical expressions are given for the output parameters of an electric generator (voltage, current, frequency, electromagnetic power, etc.) depending on its geometric dimensions, the number of permanent magnes, the connection diagram and the number of turns of the stator winding, the minimum distance between the stator and the rotor. According to the results of scientific research, an electric generator was developed with a power of 600 W, with the number of permanent magnets 32, the number of windings in each phase of the stator 4, the number of turns in each winding 200, the stator and rotor of which rotate in opposite directions. It was found that with opposite rotation of the stator and rotor relative to each other, the electromagnetic torque and electromagnetic power of the generator increase by 20% compared to a rotating rotor and a stationary stator of an electric generator. It is scientifically substantiated that by using this type of electric generator in micro hydroelectric power plants and wind power plants, it is possible to significantly increase the efficiency of installations at low currents. 

A. B. Safarov

Papers

Statistical Analysis of Wind Energy Potential in Uzbekistan’s Bukhara Region Using Weibull Distribution

Opportunities and Prospects for the Using Renewable Energy Sources in Bukhara Region

Design and modeling of dynamic modes of low speed electric generators for electric power generation from renewable energy sources