An Optimal Load Shedding Approach for Distribution Networks with DGs Considering Capacity Deficiency Modelling of Bulked Power Supply

Microgrids can be used for securing the supply of power during network outages. Underground cabling of distribution networks is another effective but conventional and expensive alternative to enhance the reliability of the power supply. This paper first presents an analysis method for the determination of microgrid power supply adequacy during islanded operation and, second, presents a comparison method for the overall cost calculation of microgrids versus underground cabling. The microgrid power adequacy during a rather long network outage is required in order to indicate high level of reliability of the supply. The overall cost calculation considers the economic benefits and costs incurred, combined for both the distribution network company and the consumer. Whereas the microgrid setup determines the islanded-operation power adequacy and thus the reliability of the supply, the economic feasibility results from the normal operations and services. The methods are illustrated by two typical, and even critical, case studies in rural distribution networks: an electric-heated detached house and a dairy farm. These case studies show that even in the case of a single consumer, a microgrid option could be more economical than network renovation by underground cabling of a branch in order to increase the reliability.

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Influence of distributed power supply in distributed power distribution network

Journal of Intelligent & Fuzzy Systems ◽

10.3233/jifs-189601 ◽

2021 ◽

pp. 1-8

Author(s):

Xin Shen ◽

Hongchun Shu ◽

Min Cao ◽

Nan Pan ◽

Junbin Qian

Keyword(s):

Power Supply ◽

Power Distribution ◽

Short Circuit ◽

Power Grid ◽

Distribution Network ◽

Distribution Networks ◽

Power Supplies ◽

Power Distribution Network ◽

Power Sources ◽

Distributed Power

In distribution networks with distributed power supplies, distributed power supplies can also be used as backup power sources to support the grid. If a distribution network contains multiple distributed power sources, the distribution network becomes a complex power grid with multiple power supplies. When a short-circuit fault occurs at a certain point on the power distribution network, the size, direction and duration of the short-circuit current are no longer single due to the existence of distributed power, and will vary with the location and capacity of the distributed power supply system. The change, in turn, affects the current in the grid, resulting in the generation and propagation of additional current. This power grid of power electronics will cause problems such as excessive standard mis-operation, abnormal heating of the converter and component burnout, and communication system failure. It is of great and practical significance to study the influence of distributed power in distributed power distribution networks.

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Power Supply Reliability Management of Distribution Networks in Honghe Region

10.1109/ciced50259.2021.9556771 ◽

2021 ◽

Author(s):

Yi Pu ◽

Jiafang He ◽

Rui Xiang ◽

Yiwei Zhang

Keyword(s):

Power Supply ◽

Distribution Networks ◽

Reliability Management ◽

Supply Reliability

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Study of power transformer loading in rural power supply systems

Safety and Reliability of Power Industry ◽

10.24223/1999-5555-2020-13-4-282-289 ◽

2021 ◽

Vol 13 (4) ◽

pp. 282-289

Author(s):

I. V. Naumov ◽

D. N. Karamov ◽

A. N. Tretyakov ◽

M. A. Yakupova ◽

E. S. Fedorinovа

Keyword(s):

Energy Efficiency ◽

Power Supply ◽

Rural Areas ◽

Power Transformer ◽

Electric Energy ◽

Power Transformers ◽

Electric Networks ◽

Load Factors ◽

Optimal Load ◽

Supply Systems

The purpose of this study is to study the effect of loading power transformers (PT) in their continuous use on their energy efficiency on a real-life example of existing rural electric networks. It is noted that the vast majority of PT in rural areas have a very low load factor, which leads to an increase in specific losses of electric energy when this is transmitted to various consumers. It is planned to optimize the existing synchronized power supply systems in rural areas by creating new power supply projects in such a way as to integrate existing power sources and ensure the most efficient loading of power transformers for the subsequent transfer of these systems to isolated ones that receive power from distributed generation facilities. As an example, we use data from an electric grid company on loading power transformers in one of the districts of the Irkutsk region. Issues related to the determination of electric energy losses in rural PT at different numerical values of their load factors are considered. A computing device was developed using modern programming tools in the MATLAB system, which has been used to calculate and plot the dependence of power losses in transformers of various capacities on the actual and recommended load factors, as well as the dependence of specific losses during the transit of 1 kVA of power through a power transformer at the actual, recommended and optimal load factors. The analysis of specific losses of electric energy at the actual, recommended and optimal load factors of PT is made. Based on the analysis, the intervals of optimal load factors for different rated power of PT of rural distribution electric networks are proposed. It is noted that to increase the energy efficiency of PT, it is necessary to reduce idling losses by increasing the load of these transformers, which can be achieved by reducing the number of transformers while changing the configuration of 0.38 kV distribution networks.

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