CN-120850790-B - Composite insulator icing numerical simulation, protection and control method

CN120850790BCN 120850790 BCN120850790 BCN 120850790BCN-120850790-B

Abstract

The invention discloses a method for simulating icing values of a composite insulator and protecting and controlling the icing values, which relates to the technical field of composite insulators, and comprises the steps of constructing a three-dimensional geometric structure model of the composite insulator; the method comprises the steps of simulating and calculating the corresponding shielding degree of each umbrella skirt based on a preset airflow field to obtain an umbrella skirt shielding index SSI of each level of umbrella skirt, acting the SSI on simulation boundary condition coefficients to obtain corrected simulation boundary condition coefficients of the surfaces of each umbrella skirt, executing simulation based on the corrected simulation boundary condition coefficients to simulate the icing growth process of each level of umbrella skirt, and outputting icing thickness distribution results of different umbrella skirt levels to analyze the influence of shielding effect on icing non-uniformity. The invention fully considers the geometric structure characteristic of the composite insulator in the axial multi-umbrella-skirt lamination arrangement, introduces the parameter of the umbrella-skirt shielding index into the simulation model for the first time, and improves the simulation precision and efficiency.

Inventors

HAN XINGBO
WANG PENGFEI
DONG SHAOJIANG
SUN SHIZHENG
LUO JIAYUAN
WU HAITAO
Fan Caijin

Assignees

重庆交通大学

Dates

Publication Date: 20260512
Application Date: 20250723

Claims (8)

1. The method for numerical simulation, protection and prevention of the icing of the composite insulator is characterized by comprising the following steps of: Constructing a three-dimensional geometric structure model of the composite insulator, wherein the model comprises a plurality of umbrella skirt structures which are axially arranged; Calculating the corresponding shielding degree of each umbrella skirt based on the simulation of a preset air flow field to obtain an umbrella skirt shielding index SSI of each level of umbrella skirt, wherein SSI is a floating point number with a value range of 0 to 1 and is used for representing the strength of the current umbrella skirt influenced by upper shielding; using SSI as an adjusting factor to act on the simulation boundary condition coefficient to obtain the corrected simulation boundary condition coefficient of the surfaces of the umbrella skirts; Based on the corrected simulation boundary condition coefficient, simulation is carried out, and the icing growth process of umbrella skirts at all levels is simulated; outputting an icing thickness distribution result of the umbrella skirt layer for analyzing the influence of the shielding effect on icing non-uniformity; The process of calculating SSI is: Performing hydrodynamic simulation on the three-dimensional model of the composite insulator in the ice-free state to obtain the local actual wind speed v n of the surface of each umbrella skirt; and defines the shed shielding index SSI n as: SSI n =1-(v n /v nr ); V nr is the reference wind speed of the nth layer, which refers to the reference wind speed of the umbrella skirt of the nth layer under the non-shielding condition; The calculation step of the n-layer umbrella skirt reference wind speed comprises the following steps: On the premise of keeping the original simulation boundary condition unchanged, a simplified geometric model of the composite insulator is constructed, and all umbrella skirt structures positioned above an n-th layer umbrella skirt are removed from the simplified geometric model; And executing hydrodynamic simulation under the ice-free condition based on the simplified geometric model, and acquiring the wind speed of the surface area of the umbrella skirt of the nth layer as a reference wind speed v nr .
2. The method for modeling and protecting and controlling icing of composite insulator according to claim 1, wherein the formula for applying SSI as a regulating factor to the simulated boundary condition coefficient comprises: h n =h nr ×(1-α×SSI n ); h nr represents a simulation boundary condition coefficient of the n-layer umbrella skirt in a non-shielding state; h n represents a simulation boundary condition coefficient after the n-layer umbrella skirt is corrected, and alpha is an adjustment coefficient.
3. The method for simulating and protecting and controlling the icing value of the composite insulator according to claim 2, wherein the simulated boundary condition coefficient comprises any one or more of a surface heat exchange coefficient, a wind speed, a liquid drop capturing efficiency and an evaporation rate.
4. The method for simulating and protecting and controlling icing of composite insulator according to claim 1, wherein the simulation process is implemented by simulation software and comprises any one or more of Fluent, openFOAM, COMSOL Multiphysics and ANSYS CFX.
5. The method for numerical simulation and protection control of icing of composite insulator according to claim 1, wherein the step of analyzing the influence of the shielding effect on the icing non-uniformity comprises: Establishing a mapping relation between each umbrella skirt number and corresponding simulated icing thickness data to generate an umbrella skirt level-icing thickness distribution table; And constructing a fitting relation curve or a correlation coefficient between the shielding index SSI n and the icing thickness H n based on the umbrella skirt layer-icing thickness distribution table, and quantitatively evaluating the influence of the shielding degree on the icing degree.
6. The method for simulating and protecting and controlling icing of composite insulator according to claim 5, further comprising outputting an umbrella skirt layer ice thickness distribution map or a shielding-icing influence map by a visual means.
7. The method for simulating and protecting and controlling icing of a composite insulator according to claim 5, further comprising the steps of constructing a training sample set based on the output icing thickness distribution result of each umbrella skirt and the corresponding umbrella skirt shielding index SSI, and modeling the mapping relation between the shielding degree and the icing non-uniformity by adopting a supervised learning model.
8. The composite insulator icing numerical simulation and protection control method according to claim 5 or 7, further comprising ordering protection control priorities of umbrella skirts based on ordering of icing thicknesses.

Description

Composite insulator icing numerical simulation, protection and control method Technical Field The invention relates to the technical field of composite insulators, in particular to a composite insulator icing numerical simulation and protection control method. Background In high-voltage transmission lines, composite insulators are widely used for replacing traditional porcelain insulators or glass insulators due to good insulating property, light weight, high strength and pollution resistance. However, the composite insulator in cold or wet cold areas is very prone to the problem of atmospheric icing during operation, and the icing not only reduces the insulation level, but also can cause tripping, flashover and even equipment damage, and is one of the key risk factors for the operation safety of the power grid. The composite insulator has the remarkable structural characteristic that the umbrella skirt part of the composite insulator is generally composed of a plurality of silicon rubber umbrella skirt structures which are uniformly distributed along the axial direction and are in a laminated shape. The multi-umbrella skirt laminated structure enhances the insulating capability to rain, snow and pollution on one hand, and brings a new icing mechanism difference, namely the geometrical shielding effect of the upper umbrella skirt to the lower umbrella skirt on the other hand. Specifically, in a natural wind field, the upper shed forms wind speed disturbance and a local low-pressure area on the lower layer, so that obvious low wind speed, high humidity and weak heat exchange areas exist on the surface of the lower shed, and the lower shed is very easy to become an anchor point for the initial attachment of ice crystals. Meanwhile, as the icing process is accompanied by complex gas-liquid-solid phase transition and heat and mass transfer processes, the micro-environmental change of the shielding area directly leads to uneven distribution of the ice coating. Although research has been conducted in an attempt to simulate the insulator icing process using CFD simulation or empirical analysis methods, most of the existing methods do not emphasize the physical mechanism of the "umbrella skirt shielding effect" in the simulation process. Especially, the umbrella skirt structure has no influence on ice-making behavior in multiple dimensions such as wind field disturbance, liquid drop capturing, heat exchange efficiency and the like, and system modeling and parameterization treatment are not yet available. Therefore, a numerical simulation method capable of fully considering the shielding effect of multiple sheds is needed, and the airflow disturbance and thermal mass coupling transmission process between the sheds is accurately reflected, so that the non-uniformity distribution simulation and the protection measure optimization of the icing behavior are realized. Disclosure of Invention The invention aims to provide a composite insulator icing numerical simulation and protection control method for solving the problems in the background art. In order to achieve the above purpose, the invention adopts the following technical scheme: the invention has the advantages compared with the prior art that: a method for simulating and protecting and controlling icing values of a composite insulator comprises the following steps: Constructing a three-dimensional geometric structure model of the composite insulator, wherein the model comprises a plurality of umbrella skirt structures which are axially arranged; Calculating the corresponding shielding degree of each umbrella skirt based on the simulation of a preset air flow field to obtain an umbrella skirt shielding index SSI of each level of umbrella skirt, wherein SSI is a floating point number with a value range of 0 to 1 and is used for representing the strength of the current umbrella skirt influenced by upper shielding; Using SSI as an adjusting factor to act on the simulation boundary condition coefficient to obtain the corrected simulation boundary condition coefficient of the surfaces of the umbrella skirts; Based on the corrected simulation boundary condition coefficient, simulation is carried out, and the icing growth process of umbrella skirts at all levels is simulated; And outputting an icing thickness distribution result of the umbrella skirt layer for analyzing the influence of the shielding effect on icing non-uniformity. Preferably, the process of calculating SSI is: Performing hydrodynamic simulation on the three-dimensional model of the composite insulator in the ice-free state to obtain the local actual wind speed v n of the surface of each umbrella skirt; And defines the shed shielding index SSI n as: SSIn = 1 - (vn / vnr); v nr is the reference wind speed of the nth layer, which refers to the reference wind speed of the umbrella skirt of the nth layer under the non-shielding condition. Preferably, the calculating step of the n-layer umbrella skirt referen