Mechatronic approach to the design of a triaxial antenna with backlash minimization by the control system

The features and advantages of the support-rotating platforms design for the antenna systems with three axes are analyzed in the paper. The expediency of using such systems for the satellite tracking without signal losses in the zenith area relative to the coordinate of the antenna system is reasoned. It is necessary in order to expand the antenna system functionality, improve the performance of the antenna device, and increase the control system efficiency and the information reliability from the spacecraft as a whole. The developed design of the 3-axial support-rotating platform is described. The platform is built on a modular principle using of modern autonomous rotary actuators, which are combined by a special design. This approach is proposed in order to ensure backlash sampling using special software algorithms of the support-rotating device control system

Methods to improve the accuracy of guidance of terrestrial antenna station

The analysis of factors influencing accuracy of guidance of terrestrial antenna complexes and ways of improvement of a signal reception quality are considered. The above considerations are the result of authors many years practical experience in the AS ground stations setting and monitoring

Comparison of different methods for evaluation of wind turbine power production based on wind measurements

Investigations of the wind shear up to the height of 200 (m) on the Latvian coast of the Baltic Sea have been carried out using a Pentalum SpiDAR laser measuring complex. Based on wind speeds measurements for three levels – 30, 40 and 50 (m), assessment of the operational efficiency of the wind turbines for heights 100, 140 and 180 (m) have been performed. For comparison, this analysis involves five different approaches: the Rayleigh frequency distribution, three different Weibull frequency distributions and method based on approximation of the cubic wind speed. Results are compared with measurements on the corresponding heights

Comparison of different methods for evaluation of wind turbine power production based on wind measurements

Investigations of the wind shear up to the height of 200 (m) on the Latvian coast of the Baltic Sea have been carried out using a Pentalum SpiDAR laser measuring complex. Based on wind speeds measurements for three levels – 30, 40 and 50 (m), assessment of the operational efficiency of the wind turbines for heights 100, 140 and 180 (m) have been performed. For comparison, this analysis involves five different approaches: the Rayleigh frequency distribution, three different Weibull frequency distributions and method based on approximation of the cubic wind speed. Results are compared with measurements on the corresponding heights

Measurements of the Wind Energy Resource in the Latvia

In the Baltic countries interest to the renewable energy is growing. Government support and availability of large unpopulated areas on the coast makes attractive use of these lands for the placement of large wind power plants (WPP). For successful implementation of planned projects reliable information about distribution of the resource of wind energy is needed. Researches in this area are carried out by collaboration IPE with VeA. The paper presents the results of years-long observations on the density fluctuations of wind energy at heights of 10 to 60 m in the area in the Baltic Sea coast in the north and the south-west of Latvia. The velocity observations from 2004 till 2010 years have been obtained by measurements complex of the LOGGER 9200 Symphonie type. The results presented in the form of tables, bar charts and graphs. The graphs of seasonal fluctuations of wind speed have been obtained for the heights up to 60 m by measurements over the period of 2007 – 2010. The histograms have been composed for the relative frequency of repetition of wind speed. The wind speed distribution on heights up to 60 m was analysed and coefficients of approximating functions for the two areas with different terrain types were calculated. Extrapolation results of the distribution curves of wind velocity and density mean values on heights up to 150 m were shown. Modelling of the acoustic noise level distribution around planned WPP from 32 wind generators was made. Calculations allow defining a zone of noise influence on environment and determining if the planned projects are in accordance with requirements of the Law of Republic of Latvia, which establishes acceptance standards of noise level in populated areas

Research of the Wind Energy Resources Distribution in the Baltic Region

Governmental support and the availability of large unpopulated areas on the coasts of the Baltic countries make attractive the use of these lands for siting large wind power plants (WPP). Studies in the area of wind energy resource distribution are carried out by the IPE with collaboration with the VeU. The observations of wind speed were made using the measuring complex NRG LOGGER 9200 Symphonie. The results of long-term observations on the wind energy density fluctuations at heights of 10 to 60 m in the area on the Baltic Sea coast of Latvia are presented in the form of tables, bar charts and graphs. The wind speed distribution is analysed. The coefficients of approximating functions for two areas of different terrain types have been calculated, and extrapolation results for the distribution curves of wind speed and energy density obtained. The acoustic noise level distribution around a planned WPP has been modelled

Problems in Assessment of Wind Energy Potential and Acoustic Noise Distribution when Designing Wind Power Plants

Interest in the use of renewable energy in Latvia is increasing every year. Government support and availability of large unpopulated areas on the coast makes the use of these lands for the placement of large wind power plants (WPP) attractive. The key factors that determine the choice of the location of WPP are reliable information about distribution of the resource of wind energy in this area and the influence of wind turbines on the environment. The paper presents the results of years-long observations on the density fluctuations of wind energy at heights of 10 to 60 m in the area in the Baltic Sea coast in Ventspils and Ainaži. The velocity observations since 2007 have been gathered by measurements complex of the LOGGER 9200 Symphonie type. The results are presented in the form of tables, bar charts and graphs. Extrapolation results of wind velocity and density mean values on heights up to 150 m for the two areas with different terrain types were shown. The distribution of acoustic noise in the vicinity of the WPP was studied and an assessment of its impact on the environment in accordance with the Latvian government requirements was conducte

Comparison of different methods for evaluation of wind turbine power production based on wind measurements

Investigations of the wind shear up to the height of 200 (m) on the Latvian coast of the Baltic Sea have been carried out using a Pentalum SpiDAR laser measuring complex. Based on wind speeds measurements for three levels – 30, 40 and 50 (m), assessment of the operational efficiency of the wind turbines for heights 100, 140 and 180 (m) have been performed. For comparison, this analysis involves five different approaches: the Rayleigh frequency distribution, three different Weibull frequency distributions and method based on approximation of the cubic wind speed. Results are compared with measurements on the corresponding heights