Analysis of Abnormal Low-voltage Line Loss in the Transformer Area Caused by Distributed Photovoltaic Access

Aiming at the insufficiency of Equivalent Resistance Method for a low-voltage distribution line loss calculation, this article has been improved. Then this paper presents the method of using three-phase quantity of electricity to calculate three-phase current, it can calculate the three-phase unbalanced line loss without current date and facilitate the application of Three-phase Unbalanced Method. It develops our own program based on Visio to calculate low-voltage distribution line loss. The results showed: Improved Equivalent Resistance Method improves the accuracy; in the three-phase unbalanced the method of using three-phase quantity of electricity to calculate three-phase current is more easily modified and more practical value.

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Load Transfer Device for Solving a Three-Phase Unbalance Problem Under a Low-Voltage Distribution Network

Energies ◽

10.3390/en12152842 ◽

2019 ◽

Vol 12 (15) ◽

pp. 2842 ◽

Cited By ~ 1

Author(s):

Guanghai Bao ◽

Sikai Ke

Keyword(s):

Load Transfer ◽

Low Voltage ◽

Distribution Network ◽

Experimental Result ◽

Central Controller ◽

Three Phase ◽

Line Loss ◽

Population Genetic Algorithm ◽

Monitoring Platform ◽

Transfer Device

In the low-voltage (LV) distribution network, a three-phase unbalance problem often exists. It does not only increase line loss but also threaten the safety of the distribution network. Therefore, the author designs a residential load transfer device for a LV distribution network that can deal with a three-phase unbalance problem by changing the connecting phase of the load. It consists of three parts: user controller for phase swapping, central controller for signal processing and monitoring platform for strategy calculation. This design was based on message queuing telemetry transport (MQTT) communication protocol, and Long Range and 4th Generation mobile telecommunications (LoRa + 4G) communication mode is used to realize the wireless connection between equipment and monitoring platform, and a control scheme is proposed. The improved multi-population genetic algorithm (IMPGA) with multi-objective is used to find the optimal swapping strategy, which is implemented on the monitoring platform. Then the phase swapping is realized by remote control, and the function of reducing three-phase unbalance is realized. The practical experimental result shows that the method can help to reduce the three-phase unbalance rate by changing the connection phase of the load, and the simulation results verify the effectiveness of the algorithm in the phase-swapping strategy.

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Optimization of low-voltage load configuration based on minimizing line loss

Information, Computer and Application Engineering ◽

10.1201/b18658-23 ◽

2018 ◽

pp. 107-110

Keyword(s):

Low Voltage ◽

Line Loss

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Research and Analysis of Reliability of Power Grid SVG Master Circuit in Rural Areas

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.713-715.1299 ◽

2015 ◽

Vol 713-715 ◽

pp. 1299-1301

Author(s):

Hong Kai Li ◽

Wei Li Wang ◽

Jin Xing Wang ◽

Shu Han Wang ◽

Li Hong

Keyword(s):

Rural Areas ◽

Low Voltage ◽

Power Grid ◽

Reliability Estimation ◽

Power Grids ◽

Reactive Compensation ◽

Line Loss ◽

Made In China ◽

Safety And Stability ◽

Made In

Problems such as low voltage and big line loss have long existing in the power grid in rural areas of China. In recent years, some province and cities have improved voltage and reduced line loss by installing SVG at substations in rural power grids, and the effect is remarkable.With great compensation capacity and a good variety of modes of compensation, SVG is sure to replace old reactive compensation devices in rural power grid in future, which requires evaluation and analysis of SVG reliability so as to guarantee safety and stability of the power grid. However, now no research or analysis has been made in China on SVG reliability in rural power grids, which affects wide promotion of SVG in rural power grids.Under the background of Liaoning Power Grid 10kV/±5Mvar Chain SVG, this paper analyzes the reliability of k/n (G) system model of SVG master circuit structure, improving the accuracy of system reliability estimation. The estimation matches the operation outcome, thus providing data basis for the feasibility of SVG’s wide application in rural power grid in future.

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Research on Predicting Line Loss Rate in Low Voltage Distribution Network Based on Gradient Boosting Decision Tree

Energies ◽

10.3390/en12132522 ◽

2019 ◽

Vol 12 (13) ◽

pp. 2522 ◽

Cited By ~ 2

Author(s):

Mengting Yao ◽

Yun Zhu ◽

Junjie Li ◽

Hua Wei ◽

Penghui He

Keyword(s):

Decision Tree ◽

Power Systems ◽

Loss Rate ◽

Low Voltage ◽

Distribution Network ◽

Gradient Boosting ◽

Data Set ◽

Economic Operation ◽

Line Loss ◽

Excessive Number

Line loss rate plays an essential role in evaluating the economic operation of power systems. However, in a low voltage (LV) distribution network, calculating line loss rate has become more cumbersome due to poor configuration of the measuring and detecting device, the difficulty in collecting operational data, and the excessive number of components and nodes. Most previous studies mainly focused on the approaches to calculate or predict line loss rate, but rarely involve the evaluation of the prediction results. In this paper, we propose an approach based on a gradient boosting decision tree (GBDT), to predict line loss rate. GBDT inherits the advantages of both statistical models and AI approaches, and can identify the complex and nonlinear relationship while computing the relative importance among variables. An empirical study on a data set in a city demonstrates that our proposed approach performs well in predicting line loss rate, given a large number of unlabeled examples. Experiments and analysis also confirmed the effectiveness of our proposed approach in anomaly detection and practical project management.

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