The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The challenge of power loss benchmark in electric traction network with parallel and traditional separated operating conditions of traction substation feeders is issued in terms of energy efficiency of urban electric transport. The traction network area of Novosibirsk tram with high power supply imbalance was chosen and experimental measurements were made with operating conditions being reviewed....
This paper presents a study of a processes in the three-port converter under different modes of operations. Circuit topology provides a compact size of the device, allows to get zero pause and decrease losses. The modeling reflects the experimental results.
Dynamical analysis improvement and its capabilities extension are important for the complex analysis and synthesis of the vibratory electromagnetic drive applied in engineering systems for exciting low-frequency oscillations and vibrations. A single-mass vibratory system is considered to be a test subject. Its electromagnetic drive is powered from a sinusoidal voltage source through a half-wave rectifier...
Single-phase inverters suffer from double-frequency ripple of the input power. For mitigation, an input capacitor is applied but the fluctuation range of power across it is limited according the desired fluctuation in the dc-link voltage. To realize power decoupling without changes in the main circuit and in the control strategy of it, an additional independent power decoupling circuit can be applied,...
Specific energy consumption related to the bus of traction substation is considered as a criterion of energy recuperation efficiency in the paper. It is shown that in this case we take into consideration not only the pert of braking energy in total value of energy consumed in traction mode but also real value of energy loses in power supply system. The method is proposed that allows to estimate a...
Measurement of quality indicators of electric power is very comprehensive in terms of the calculation process, the situation is complicated by overlapping interference and the need to divide the interference before measuring specific indicators of quality of electric energy. Neural network and Fuzzy logic can be used as the means of data processing. This may allow to get rid of complex mathematical...
The results of the aerodynamic optimization of wind-driven power-plant (WP) with a vertical axis of rotation, axially symmetric stator and special form rotor are presented. It is shown that WP using useful interference of the stator and the rotor, on the energy characteristics superior to the classical WP ceteris paribus. Prospect for WP development consists of variable geometry elements using, that...
In this paper the structure and principle work of electronic transformer scheme with intermediate elements of DC were discussed. Through simulation modeling time diagrams of this scheme were obtained. Assessment of the harmonic distortion input current and output voltage was held. Approximate calculation of the efficiency of the electronic transformer was carrying out.
This paper considers the issue how to obtain the amplification of stimulated emission in the cell with sodium vapor using a longitudinally pumped dye laser arrangement at a line shorter than the transitions from the ground state to the levels D1 and D2. The broadening of the emission wavelength is calculated.
The results of the energy submodel development for the optical-electronic device of a two spectral ratios are given in article. The adaptation of the generalized technique of an energy calculation was executed. The basic data for the energy submodel building were selected. The algorithm of the computer program which allow to calculate the spectral ratios in case of a different values of the diameter...
In this paper, the experimental studies of copper bromide vapor brightness amplifiers operating at high pulse repetition frequencies are presented. The obtained results show that the injection of active hydrogen-containing additives allows to increase the radiation (gain) pulse repetition frequency in active elements with a diameter of the active zone larger than 1 cm.
The article describes prospects for the development of multicriterion electro-optical system for alarm and pre-emergency situations control in a coal mine. The problems of scientific research, the implementation of which will improve fire safety in coal mines are formulated.
The purpose of the current paper is to validate experimentally the possibility to combine optical and computer methods for image processing. The X-ray imaging is one of the most efficient methods for inspection of the nuclear fuel elements (NFE). X-rays pass through the inspected object and cause various degrees darkening of the film placed behind the object. The visual analysis of the x-ray images...
Modeling of flame radiation at burning of methane-air mixtures at an initial stage of development is executed. The basic analytical dependences for modeling are defined at an assumption, that burning is isothermal on volume and has the sphere form. Calculation of spectral radiant exitance from a surface of fireball is executed. Irradiance on an elementary platform depending on distance to fireball...
In this paper the new method of transfer function linearization without limitation for calibration flux was suggested. Suggested method was tested on the test transfer function and the mean transfer function of photodetector array. Tests have shown method effectiveness.
The method of automatic parameters adjustment of LDA signals detection system providing improving of accuracy, efficiency and reliability of physical experiments and reducing qualification requirements to experimenter is proposed. The method is based on statistical analysis of parameters of Doppler signals and noise and parametric optimization with maximum reliable signals criterion. An essential...
Article describes movement control algorithm of the fire robot based on a quadcopter along predetermined trajectory in the secure premise. Known approaches to determining of the fire robot location are analyzed. The approach to determining of the fire robot location is chosen taking into account requirements to the robot. The mathematical apparatus for determining of quadcopter coordinates and control...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.