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EN
The article gives results of the development of the system of monitoring for photovoltaic power installations with different configuration to study the factors, increasing their productivity. Differentiation of impact, made by the components of different structure of photovoltaic power installations is made by application of three independent controlled channels of energy extraction from photovoltaic panels: fixed focused, with application of solar tracker and with application of solar tracker, having flat mirror concentrators. To secure originality of the record of the electric energy, produced by photovoltaic panels, we have developed unit of control for discharging current of battery banks in each channel. It supports equal level of their charge. Amount of the produced electric energy in each channel is estimated by the value of discharge. Control and measuring system is made on the base of virtual devices with hardware unit of input/output of NI USB-6009 type, produced by National Instruments Company, with software LabVIEW. In the research, software code of the system of monitoring and front panel of operator have been developed. The work provides photos of the developed experimental stand.
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This paper analyzes the methods of mapping the velocity of wind flow, and using them to measure the performance of wind turbines. The dependencies of the two-parameter Weibull distribution function on the scale parameter are analyzed. It should be noted that the parameters of the distribution function, and therefore the repeatability are probabilistic. The characteristics of Rayleigh distribution for different values of the scale are presented. The analytical-expressions and peculiar velocities of the integer and half-integer values for the shape parameters reflect the relationship between the mean, mean square, average-cubic, and estimated wind-speeds. It is shown that the ratio of the square of the average speed to the standard, regardless of the values of the shape-parameters and the scale-ratio can be replaced by the corresponding G-functions.The theoretical-calculation to design the medium-speed and its relation to the current and average speeds for the Weibull distribution with a half-integer values and the shape-parameter is presented. It is proved that the recommendation considers the speed of the medium design to be proportional to the mean, and permissible only if the distribution is close to normal. It has been established that the ratio between average wind velocities (in the case of Weilbull distribution parameter) are determined only by its form and the average velocity through the scale parameter. Weibull distribution allows to facilitate and simplify their calculation methodology so as to assess the energy parameters of wind turbines.
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