## 1 Introduction  
As a core component of the national infrastructure, the power system plays a crucial role in the construction and renovation of urban and rural power grids. Against the backdrop of rapid economic development and a continuous growth in power demand, the efficiency and reliability of power supply are particularly important [1]. Box-type substations, characterized by their compact structure, small footprint, and unmanned operation features, have been widely used in modern power systems. By integrating high-voltage switchgear, distribution transformers, and low-voltage distribution devices, box-type substations provide a flexible and efficient power supply solution for the grid. However, the structural design of box-type substations is a key determinant of their quality and service life. Once a box-type substation malfunctions, it can have significant impacts on the urban and even national power supply, thereby adversely affecting the national economy. Therefore, conducting an in-depth simulation analysis and research on the operational status and design performance of box-type substations in extreme natural environments, and proposing corresponding engineering recommendations and design measures to ensure the structural safety and reliability of box-type substations, is of paramount importance. In recent years, domestic and foreign scholars have conducted a series of studies on the resistance performance of box-type substations under extreme conditions such as typhoons, snowstorms, and earthquakes. In seismic research on building structures and electrical equipment, the static analysis method, response spectrum analysis method, and time-history analysis method are commonly employed [2]. [PERSON] et al. [3] designed a box-type substation typhoon-resistance test device and its test procedures, conducted a test analysis of the box-type substation's typhoon resistance capability, and proposed key designs and methods to enhance its typhoon resistance capability. Process improvement verified the reliability of the optimized design solution. [PERSON] et al. [4] proposed an equivalent static wind load method suitable for multi-response and determined that wind load is one of the important loads in the design of long-span roof structures. [PERSON] et al. [5] conducted a finite element analysis on a 110 kV box-type substation under seismic strong wind conditions, verifying its safety. They extended this analysis method to the areas of substation design and force verification safety, which can provide certain guidance for similar work. [PERSON] et al. [6] invented a vertical box-type substation with shock absorption, focusing on the impact of vibration on substations. However, there are relatively few patents related to snow and wind prevention, as well as earthquake conditions. [PERSON] et al. [7] employed experimental and theoretical analysis methods to compare dynamic characteristics, such as the natural frequencies of steel frame structures with and without supports. They proposed that, during the study of structural seismic performance, the static and dynamic characteristics of the structure should be checked first. According to the research of [PERSON] et al. [8], earthquakes can cause structural oscillation or damage, and their acceleration effects can exacerbate resonance. Therefore, when designing structures for seismic resistance, it is necessary to evaluate their modal results and ensure that their seismic performance is not affected by resonance. These studies, through experimental and theoretical analysis, not only validate the structural safety, but also offer valuable insights for enhancing the design and seismic resistance, of box-type substations. While these studies provide crucial theoretical and experimental evidence for understanding the performance of box-type substations under individual extreme conditions, in real-world scenarios, box-type substations often need to withstand the combined effects of multiple loads such as wind, snow, and earthquakes.