scholarly journals The Research on DC Loop of Regional Power Grid Caused by the Operation of the Subway

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 613
Author(s):  
Lin Du ◽  
Sha Chang ◽  
Shiying Wang

The operation of the subway would change the distribution of the ground potential along the rail, forming a DC loop through the grounding points in a nearby regional power grid and threatening the operational safety of the power system. In this paper, a new DC potential distribution calculation method along the subway is firstly proposed. Secondly, a grid grounding DC loop model is built on the foundation of the stray current principle. Thirdly, factors affecting the current in the grid are also presented and discussed based on the grounding loop model. Finally, a subway operation simulation platform is set up in a laboratory to simulate the operation of subway in situation, and the rationality of the model presented in this paper has been effectively verified.

2018 ◽  
Vol 53 ◽  
pp. 01012 ◽  
Author(s):  
Wei Pan ◽  
Caijia Lei ◽  
Wei Jia ◽  
Hui Gao ◽  
Binghua Fang

Regarding analysis of load characteristics of a power grid, there are multiple factors that influence the variation of load characteristics. Among these factors, the influence of different ones on the change of load characteristic is somewhat different, thus the degree of influence of various factors needs to be quantified to distinguish the main and minor factors of load characteristics. Based on this, the grey relational analysis in the grey system theory is employed as the basis of mathematical model in this paper. Firstly, the main factors affecting the load characteristics of a power grid are analysed. Then, the principle of quantitative analysis of the influencing factors by using grey relational grade is introduced. Lastly, the load of Guangzhou power grid is selected as the research object, thereby the main factor of temperature affecting the load characteristics is quantitatively analysed, such that the correlation between temperature and load is established. In this paper, by investigating the influencing factors and the degree of influence of load characteristics, the law of load characteristics changes can be effectively revealed, which is of great significance for power system planning and dispatching operation.


2011 ◽  
Vol 243-249 ◽  
pp. 4375-4380
Author(s):  
Yuan Chun Huang ◽  
Jian Li ◽  
Haize Pan

Through analyzing the factors affecting passengers’ path-choice, the corresponding principles and rules of the ticket income distribution are put forward and the new model of the Urban Rail Transit Network in Beijing is set up in the paper. Through the deformation of the urban rail transit and the simplification of the lines, the topology of the urban rail transit lines is abstracted into an undirected connection graph. Breadth-priority optimization algorithm is applied to search the effective paths between the OD and the flow-matching ratio is acquired by calculating based on multi-factor matching algorithm, in which many relevant numerical examples are analyzed to verify the feasibility of the dual-ratio method and to summarize the characteristics of the project.


2019 ◽  
Vol 235 ◽  
pp. 1541-1550 ◽  
Author(s):  
Zifa Liu ◽  
Zhe Zhang ◽  
Ranqun Zhuo ◽  
Xuyang Wang

2018 ◽  
Vol 32 (34n36) ◽  
pp. 1840098
Author(s):  
Yuan Li ◽  
Huifang Shen ◽  
Chao Xiong ◽  
Yaofei Han ◽  
Guofeng He

In order to eliminate the effect on the grid current caused by the background harmonic voltage and the reference signal on the grid connected multi-inverter, this paper adopts the double closed-loop feed-forward control strategy. This strategy is based on the inductor voltage and the grid-connected current, and the integrated control strategy of quasi-proportional resonance loop parallel to a specific harmonic compensation loop. Based on the closed-loop model of multiple inverters, the change curves of the transfer function of the two control strategies are compared with the feed-forward control and the composite proportional resonance. The two corresponding control methods are used to analyze the current quality of the multi-inverter impact. Finally, the MATLAB/Simulink simulation model is set up to verify the proposed control strategies. The simulation results show that the proposed method can achieve better tracking of the sinusoidal command signal at the fundamental frequency, and enhance the anti-interference ability of the system at the 3rd, 5th, and 7th harmonic frequency.


2018 ◽  
Vol 227 ◽  
pp. 02017
Author(s):  
Jianchang Lu ◽  
Dandan Xing

In view of the change in the profit model of the power grid under the new power reform, If grid companies want to improve their economic efficiency, they must expand the scale of effective assets of fixed assets and increase the number of effective assets within the understanding of the demand for electricity.By determining the factors affecting the power grid investment in the new environment,a risk model for the power grid investment under the new power reform is constructed.First,this paper uses the set pair analysis method algorithm and derives the relevant formula to quantify uncertainties in grid investment risk.Then,it gets the results of the calculation of the degree of connection of each scheme and combine set pair events with a net present value less than 0 for each set evens.At last,based on the above results,we get the best investment plan.Verified by the case of the HBN grid company,it shows that the investment risk model established is feasible and can provide an appropriate reference for the new power companies to change their investment decisions.


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