The article is devoted to the thyristor voltage regulator (TVR) development. The TVR purpose is to control power flows and regulate voltage in 6-20 kV distribution electrical networks (DEN). The principle of TVR operation is based on the plus EMF (or minus EMF) introduction into power line when the shared use of longitudinal (change of magnitude) and transverse (change of phase) voltage regulation. The description of the TVR prototype is given. The TVR prototype consists of a 0.4 kV thyristor switches, power transformers (shunt and serial) and a 6 kV switchgear. The TVR has a two-level control system (CS). The TVR prototype experimental research was conducted in four stages: check of power equipment, first level CS research, second level CS research, prototype tests as a whole. The connection diagrams (thyristor switches unit, transformer and measuring equipment) and contact connections reliability were checked when the power part was tested. A qualitative characteristic of the input and output signals was obtained when testing the first level CS. It is found that the thyristor control pulses are formed according to the developed algorithm. The correctness of control system algorithms, executed and transmitted commands, passed and received data was confirmed as a result of the second level CS tests. The TVR research results indicate that the prototype provides the smoothness and specified accuracy of voltage regulation in all modes. The control range of the output voltage relative to the input was ±10%. The discreteness of regulation did not exceed 1.5%. The range of change in the shift angle of the output voltage relative to the input was ±5°. Research confirmed the TVR ES operability and its readiness for trial operation.
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The article considers the problems, promotion and support of the export potential of agricultural products at the regional level, which should become the next growth point for Russian agriculture. The practice of the last decade in the agricultural sector of Russia shows a significant transformation from the predominance of food imports to the realization of export potential. So, in the Orel region, the export of agricultural products tends to increase; in 2019, agricultural products were exported at $ 88.8 million (growth by 2017 was 24.8%). The leading position in the export structure of Orel agribusiness is wheat, an important direction of regional export is also given to oil and oilseeds, which are the fastest growing industries on the world market, and the Orel region contributes to their development. Despite the reduction grain crops areas in the Orel region, the forecast for the harvest of 2020 is 3 million tons. The Orel region sees the main task of the agro-industrial complex in reaching the total gross harvest of crop production in the amount of 3.7 million tons, which will provide jobs, processing raw materials. The list of directions of state support for export of agricultural products is given. The conclusion is drawn about the most significant prospects for the export potential of agricultural products at the regional level, where its further development is laid. The article emphasizes the need to stimulate the activities of exporters of agricultural products through reducing the cost of exported products.
The state of gauge geometry is the basis for safe and uninterrupted train operations under the mixed traffic conditions, as well as in the sections where trains with increased weight and length, including wagons with an increased axle load, are handled. When passing such trains, the state of gauge geometry deteriorates. This leads to increased labour costs for track maintenance, which is also caused by climatic features. Under such conditions, it is important to carry out effective gauge maintenance works. To analyse an impact of maintenance on gauge geometry, it is offered to determine the effect of uneven settlement of the under sleeper base in spring on the dynamics of each type of deviation. To evaluate the efficiency of preventive track alignment in the plan and profile, an analysis of graphical charts for the state of gauge geometry depending on track maintenance by gangs of track fitters and preventive track alignment by machine systems was carried out. It is also revealed that the efficiency of preventive alignment is significantly reduced under harsh climatic conditions, especially for the tonnage handled exceeding 600 million tonnes gross, and should therefore be carried out more frequently.
Special thermometers are used to measure the temperature of grain in the fluidized bed. There are, for example, thermocouples. They are based on the following principle. If you take two plates of dissimilar metals, such as copper and iron, the ends of their soldering, the heating of this solder and cooling of the free ends of the plates of electric current will flow. The higher the temperature of heating of the junction, the greater the value of the current, which is registered by a special device. To measure temperatures in the fluidized bed, the method of placing a group of fixed thermocouples in different zones - both along with the height of the bed and in the radial direction - is applied. Since measurement of layer temperature is considered, it was considered whether the thermocouple placed in the layer measures the temperature of the grain or the temperature of the drying agent, or perhaps some average temperature between the two. During the drying process, the temperature was determined immediately below the grate, as well as at different heights of the layer. From the experimental data, it can be concluded that the layer temperature for all practical calculations can be assumed to be equal to the temperature of the grain in the upper zones of the layer. Since already at small distances from the gas distribution lattice the temperature of the grain and the drying agent are almost equalized. In the field of drying of grain to the conditioned moisture in the fluidized state, studies of drying of grain material at different layer heights have been conducted, allowing to determine the optimal technological parameters of the dryer, to prevent overheating of grain, to preserve its food and sowing qualities. The grain drying method does not affect the environment.
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