Etat de developpement des energies renouvelables au Royaume Uni : geothermie, solaire, hydraulique, energie des vagues et des marees

Renewable energy sources in the UK

This article presents material based on the results of the analysis of literature sources on automatic devices for regulating reactive power in power supply systems. The operating mode of the compensating devices is determined taking into account the permissible voltage deviations at the terminals of the electric power receivers. Voltage, load current, reactive power directions, power factor, phase angle between the supply voltage and load current, and time can be used as control parameters. In addition, the article provides information regarding the performance of the developed circuits of contactless devices and verification of the experimental study of the operation of installations with their use. Also presented is material on the experimental study of a prototype of a contactless switching device for automatic power control of capacitor banks in various operating modes. Summarizing the results of experimental studies of a new device for automatic power control of capacitor banks, it can be stated that it fully meets the requirements for such devices and can ensure reliable operation of the power supply network with an appropriate power factor.

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Development and experimental study of circuits of contactless device for automation of compensation of reactive power of capacitor batteries

This article describes the results of the structural analysis of power losses in (6-10 / 0.4 kV) electric distribution networks of the city of Dushanbe of the Republic of Tajikistan. The data of the number and installed capacity of transformer of (6-10 / 0.4 kV) substations and the length of the (0.4-6-10 kV) transmission lines of distribution networks of the city of Dushanbe are given. The structure of power losses by voltage levels and types of losses is presented. The values of power losses in the studied electric distribution networks in Dushanbe are compared with the average values of losses in electric networks of Russia. Identified significant differences in the ratios of load and conditionally - constant losses in the distribution networks of 6-10 / 0.4 kV Dushanbe and Russia.

Structural Analysis of Power Losses in (6-10 / 0.4 kV) Urban Distribution Electric Networks of the City of Dushanbe, the Republic of Tajikistan

Nowadays the use of renewable energy sources (RES) has become an essential factor for providing sustainable development in the energy sector in the developed countries. Considering this factor, the Republic of Tajikistan is involved in the development of RES. In this case, analysis, calculation and evaluation of RES resources of the Republic of Tajikistan are considered in this paper. After that, the analysis calculations to clarify the potential of capacity of renewable energy on the territory of the country has been carried out. Further, the potential of renewable energy in the Republic of Tajikistan was assessed. After the evaluation of RES, the calculation was carried out to determine the gross, technical and economic potential of RES in the territory of the Republic of Tajikistan. It was determined that the country has great opportunities for using renewable energy. In addition, by using RES, the Republic has a great potential for the supplying electric energy to the consumers living in hard to reach mountainous areas of the country.

Analysis and Evaluation of Potential of Renewable Energy Resources of Republic of Tajikistan

This article discusses the theoretical solution of problems to determine losses in the process of transmission of electricity through overhead power lines, the fluctuation of resistivity is determined depending on the change in ambient temperature, the structure of losses on overhead power lines is given. As an example, for solving these problems, the data of power transmission lines with a voltage of 35 kV in the territory of the Sughd region of Republic of the Tajikistan were applied, the change in losses between the two regions was calculated and compared. Recommendations for reducing losses on overhead power lines are offered.

Impact of Climatic Factors on Electricity Losses on Aerial Power Lines

In this paper, the operating modes of the 0.4 kV main transmission line, in Dushanbe city of the Republic of Tajikistan, with distributed solar generation are considered. Variations of regimes are studied with respect to the location of distributed solar generation at the beginning, middle and end of the transmission line. It is found that when the solar generation is placed at the beginning of the line, the power losses and the voltage deviation will be greater at the end of the line. If a solar generation is installed at the beginning and end of the line, the voltage deviation will be greater in the middle of the line. With a uniform distribution of load and solar generation along the line, power losses and voltage will be evenly distributed.

Study of the operating modes of the 0.4 kV main distribution network, in Dushanbe city of the Republic of Tajikistan, with distributed solar generation for power losses and power quality estimation

In this paper, the results of load graphs measurements in the electrical network of public health facilities in Dushanbe (Republic of Tajikistan), to which solar cells are connected, are considered. In addition, the effect of connecting solar cells on the load graph configuration of the power supply system is analyzed. From the results of analysis, obtained that the average values of the load factor (density) and the irregularity factor of the load curve are almost unchanged, and the value of the shape factor after connecting the solar panels tends to decrease. The relative power loss values in distribution networks before and after the connection of solar cells are compared. It is found that, in some cases solar generation can lead to an increase in relative power losses. The problem of excess solar generation during the weekend, which leads to active power transfer from the consumer to the grid, is detected.

Impact of solar generation connected to 0.4 kV grid on the power losses and the shape factor of load curve

The operating modes of network-driven inverters of solar power plants using the example of the city of Dushanbe from the point of view of the influence on the power quality in 0.4 kV-distributed networks have been discussed in this paper. Evaluated results of measurement of the power quality parameters and auxiliary parameters on the considered power facility in which the installed solar power up to 50 kW. The mode of operation of the network-driven inverters by a duration of 7 days is considered. According to the result, the negative effect of the inverter in the network and the influence of the frequency and voltage deviation on the operation mode of the inverters are obtained.

Analysis of the Influence of the Operation of Network-driven Inverters of Solar Power Plants on the Operation Mode of 0.4 kV Electrical Network in Terms of Electromagnetic Compatibility

Sirojiddin R. Chorshanbiev

Papers

Study of the operating modes of the 0.4 kV main distribution network, in Dushanbe city of the Republic of Tajikistan, with distributed solar generation for power losses and power quality estimation

Structural Analysis of Power Losses in (6-10 / 0.4 kV) Urban Distribution Electric Networks of the City of Dushanbe, the Republic of Tajikistan

Analysis and Evaluation of Potential of Renewable Energy Resources of Republic of Tajikistan

Impact of solar generation connected to 0.4 kV grid on the power losses and the shape factor of load curve

Analysis of the Influence of the Operation of Network-driven Inverters of Solar Power Plants on the Operation Mode of 0.4 kV Electrical Network in Terms of Electromagnetic Compatibility