# Effect of Tree Quantity and Distribution on the Electric Field under Transmission Lines
## 5 Conclusions  
In this paper, through the study of transmission lines about different voltage levels, the basic law of power frequency electric field change under transmission lines is obtained, and the influence of a tree's electromagnetic parameters on the power frequency electric field distribution of 500 kV transmission lines is studied by changing the number and location of trees. The following main conclusions were drawn:  
1. The change trend of power frequency electric field strength with lateral distance is the same for transmission lines with and without overhead ground lines, and the error of the maximum power frequency electric field strength of both is within 5%, so in order to improve the calculation efficiency and reduce the calculation memory, the 3D electric field simulation calculation of transmission lines can be calculated according to the model without overhead ground lines.
2. When the phase angle of voltage A is 30 degrees, the change curve of its power frequency electric field strength with lateral distance is symmetrical about the middle conductor, and the maximum value of its power frequency electric field strength appears below the side conductor.
3. With the increase in the number of trees, the maximum value of power frequency electric field strength below the side conductor decreases gradually. Therefore, it is possible to move the green belt of trees to the inside of the corridor, so as to achieve the purpose of reducing the width of the transmission corridor and reducing the electric field strength below the side conductor.  
However, some limitations can be expected. The simulated charge method used in this paper is the most classical algorithm, which is not combined with the method of calculating the electric field strength, so it is not comprehensive and efficient. In addition, the tree model in this paper is only a Xing'an larch model, which may not be suitable for the requirements of most regions.  
For future work, we intend to use more integrated algorithms to predict the electric field strength of transmission lines and calculate the impact of different tree types on the width of transmission corridors.  
Figure 11: Longitudinal distribution of power frequency electric field for different widths.  
**Author Contributions:** [PERSON] proposed the topic of the review. [PERSON] surveyed the literature and composed the manuscript. [PERSON] conducted the literature review. [PERSON], [PERSON] and [PERSON] discussed and revised the manuscript. [PERSON] and [PERSON] supervised this project. [PERSON] and [PERSON] contributed equally to this work. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded in part by the National Natural Science Foundation of China under Grant 52077161.  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
**Conflicts of Interest:** The authors declare no conflicts of interest.