CN-121980658-A - Method and system for designing size of grounding body of tower pile foundation external application cage structure

CN121980658ACN 121980658 ACN121980658 ACN 121980658ACN-121980658-A

Abstract

The invention discloses a method and a system for designing the size of a grounding body of a tower pile foundation external application cage structure, which relate to the technical field of grounding of an electric power system, and are characterized in that equivalent resistance conversion is carried out according to target impact grounding resistance and design basic parameters to obtain corresponding equivalent power frequency grounding resistance, key size back calculation is carried out according to the design basic parameters based on the equivalent power frequency grounding resistance and a preset resistance contribution ratio to obtain corresponding key structure size parameters, the equivalent power frequency grounding resistance is verified and corrected according to the design basic parameters and the key structure size parameters to obtain corresponding corrected impact grounding resistance, and the key structure size parameters are optimized by adopting the corrected impact grounding resistance and the target impact grounding resistance to obtain corresponding key structure size design parameters. The method solves the technical problems that the deviation rate of the target resistance is higher and the suitability of the grounding body of the tower pile foundation external application cage structure is reduced in the existing grounding body size design method.

Inventors

LI XINHAI
XIONG ZHENDONG
LI CHUIYOU
XUE XUMING
ZHOU YI
CHEN SIJIN
CHEN HAOMING
ZHOU YUPENG
MENG CHENXU
CHENG RUI
WU YIJIANG
DONG ZHICONG
ZENG LINGCHENG
WU MIANTING
LIANG GUOJIAN
LI BEI
Chan Qizhong
JIANG YUHUAN

Assignees

广东电网有限责任公司中山供电局

Dates

Publication Date: 20260505
Application Date: 20260129

Claims (10)

1. A method for designing the size of a grounding body of a tower pile foundation external application cage structure is characterized by comprising the following steps: Obtaining a design basic parameter and a target impulse grounding resistance of a grounding body of the tower pile foundation external application cage structure, and carrying out equivalent resistance conversion according to the target impulse grounding resistance and the design basic parameter to obtain a corresponding equivalent power frequency grounding resistance; Performing critical dimension back calculation according to the design basic parameters based on the equivalent power frequency grounding resistance and a preset resistance contribution ratio to obtain corresponding critical structural dimension parameters; Checking and correcting the equivalent power frequency grounding resistance according to the design basic parameters and the critical structure size parameters to obtain a corresponding corrected impact grounding resistance; and optimizing the critical structure size parameter by adopting the corrected impact grounding resistor and the target impact grounding resistor to obtain a corresponding critical structure size design parameter.
2. The method for designing the size of the grounding body of the tower pile foundation externally-applied cage structure according to claim 1, wherein the design basic parameters comprise lightning current peak values and soil resistivity, and the step of performing equivalent resistance conversion according to the target impulse grounding resistance and the design basic parameters to obtain corresponding equivalent power frequency grounding resistance comprises the following steps: Multiplying the lightning current peak value, the soil resistivity and a preset conversion coefficient to obtain a corresponding first multiplication value; Multiplying the arithmetic square root of the first multiplication value with a preset impact correction coefficient to obtain a corresponding second multiplication value; Adding the second multiplication value with a preset impact reference value to obtain a corresponding impact coefficient; And multiplying the impact coefficient and the target impact grounding resistance to obtain a corresponding equivalent power frequency grounding resistance.
3. The method for designing the size of the grounding body of the tower pile foundation external application cage structure according to claim 1, wherein the step of performing the inverse calculation of the critical size according to the design basic parameter based on the equivalent power frequency grounding resistance and the preset resistance contribution ratio to obtain the corresponding critical structural size parameter comprises the following steps: Inputting the design basic parameters and the equivalent power frequency grounding resistance into a preset power frequency total resistance function to obtain a corresponding first power frequency total resistance; Determining a target annular grounding electrode parallel resistor and a target vertical grounding electrode parallel resistor corresponding to the first power frequency total resistor based on a preset resistor contribution duty ratio and a preset resistor back calculation function; Solving a preset inverse calculation function of the size of the annular grounding electrode according to the target annular grounding electrode parallel resistor and the design basic parameter to obtain a corresponding annular grounding electrode diameter, an annular layer number, a conductor equivalent diameter and an annular layer interval; Solving a preset inverse calculation function of the vertical grounding electrode size according to the target vertical grounding electrode parallel resistor and the design basic parameter to obtain the corresponding vertical grounding electrode length, vertical number and vertical grounding electrode diameter; And determining the diameter of the annular grounding electrode, the annular layer number, the equivalent diameter of the conductor, the annular layer spacing, the length of the vertical grounding electrode, the vertical number and the diameter of the vertical grounding electrode as key structural dimension parameters.
4. The method for designing the size of the grounding body of the tower pile foundation externally-applied cage structure according to claim 1, wherein the step of verifying and correcting the equivalent power frequency grounding resistance according to the design basic parameter and the critical structural size parameter to obtain a corresponding corrected impact grounding resistance comprises the following steps: inputting the design basic parameters and the critical structure size parameters into a preset spark effect function to obtain corresponding spark correction coefficients; multiplying the spark correction coefficient with the equivalent power frequency grounding resistor to obtain a corresponding reference impact grounding resistor; inputting the design basic parameters and the critical structure size parameters into a preset inductance effect function to obtain corresponding target annular grounding electrode equivalent inductance and target vertical grounding electrode equivalent inductance; And correcting the reference impulse grounding resistance according to the target annular grounding electrode equivalent inductance, the target vertical grounding electrode equivalent inductance and the design basic parameter to obtain a corresponding corrected impulse grounding resistance.
5. The method for designing the size of the grounding body of the tower pile foundation externally-applied cage structure according to claim 4, wherein the design basic parameters further comprise wave front time, the step of correcting the reference impact grounding resistance according to the target annular grounding pole equivalent inductance, the target vertical grounding pole equivalent inductance and the design basic parameters to obtain a corresponding corrected impact grounding resistance comprises the following steps: adding the target annular grounding electrode equivalent inductance and the target vertical grounding electrode equivalent inductance to obtain a corresponding total inductance; performing ratio processing on the total inductance and the wavefront time to obtain a corresponding inductance additional resistance; and adding the inductance additional resistor and the reference impulse grounding resistor to obtain a corresponding correction impulse grounding resistor.
6. The method for designing the size of the grounding body of the tower pile foundation externally-applied cage structure according to claim 4, wherein the spark effect function is specifically as follows: ; ; ; ; ; Wherein, the For the equivalent radius of the spark passage, In order to achieve the specific resistance of the soil, In order to be a peak value of the lightning current, For the time of the wave front, For the field strength of the breakdown of the soil, As a result of the spark correction coefficient, For the total effective current spreading length of the ground body, Is the minimum power frequency dispersion radius, For the modified equivalent dispersion radius, For the length of the vertical ground electrode, Is formed by the number of annular layers, Is the annular layer spacing and is provided with a plurality of layers, Is the diameter of the vertical grounding electrode, Is the equivalent diameter of the conductor, and is, Is the diameter of the annular grounding electrode.
7. The method for designing the size of the grounding body of the tower pile foundation externally-applied cage structure according to claim 4, wherein the inductance effect function is specifically: ; ; Wherein, the Is the equivalent inductance of the target annular grounding electrode, Is a single-layer annular grounding electrode equivalent inductance, Is formed by the number of annular layers, Is the magnetic permeability of the vacuum and is equal to the magnetic permeability of the vacuum, Is the diameter of the annular grounding electrode, The equivalent inductance is vertically and extremely equivalent to the target, Is the equivalent inductance of a single vertical grounding electrode, In the case of a vertical number of such devices, Is the vertical ground electrode diameter.
8. The method for designing the size of the grounding body of the tower pile foundation externally-applied cage structure according to claim 1, wherein the step of optimizing the critical structural size parameter by adopting the corrected impact grounding resistor and the target impact grounding resistor to obtain the corresponding critical structural size design parameter comprises the following steps: when the corrected impulse grounding resistance is larger than the target impulse grounding resistance, adjusting the vertical grounding electrode length or the annular grounding electrode diameter of the key structure size parameter based on a preset adjusting step length, and jumping to execute the step of verifying and correcting the equivalent power frequency grounding resistance according to the design basic parameter and the key structure size parameter to obtain a corresponding corrected impulse grounding resistance; When the corrected impulse grounding resistance is smaller than or equal to the target impulse grounding resistance, calculating a deviation value between the corrected impulse grounding resistance and the target impulse grounding resistance; When the deviation value is larger than a preset deviation threshold value, adjusting the critical structure size parameter based on a preset adjustment strategy, and jumping to execute the step of checking and correcting the equivalent power frequency grounding resistance according to the design basic parameter and the critical structure size parameter to obtain a corresponding corrected impact grounding resistance; And when the deviation value is smaller than or equal to the deviation threshold value, determining the critical structure size parameter as a critical structure size design parameter.
9. A tower pile foundation external application cage structure grounding body size design system which is characterized by comprising: The acquisition module is used for acquiring design basic parameters and target impulse grounding resistance of the grounding body of the tower pile foundation external application cage structure, and carrying out equivalent resistance conversion according to the target impulse grounding resistance and the design basic parameters to obtain corresponding equivalent power frequency grounding resistance; the back calculation module is used for carrying out key dimension back calculation according to the design basic parameters based on the equivalent power frequency grounding resistance and the preset resistance contribution ratio to obtain corresponding key structural dimension parameters; The correction module is used for carrying out verification correction on the equivalent power frequency grounding resistance according to the design basic parameter and the key structure size parameter to obtain a corresponding corrected impulse grounding resistance; and the optimization module is used for optimizing the critical structure size parameter by adopting the corrected impact grounding resistor and the target impact grounding resistor to obtain a corresponding critical structure size design parameter.
10. An electronic device comprising a memory and a processor, wherein the memory stores a computer program which, when executed by the processor, causes the processor to perform the steps of the method for sizing a cage structure for external application of a pole pile foundation as claimed in any one of claims 1 to 8.

Description

Method and system for designing size of grounding body of tower pile foundation external application cage structure Technical Field The invention relates to the technical field of grounding of power systems, in particular to a method and a system for designing the size of a grounding body of a cage structure for external application of a tower pile foundation. Background Under the current continuous pushing of global energy transformation, the construction of the power grid in China is in an ultra-high voltage and intelligent high-speed development stage. The extra-high voltage backbone net frame is continuously encrypted, the installed capacity of new energy power generation such as wind power and photovoltaic is increased in an explosive manner, and the power grid coverage is gradually expanded to special areas such as northwest areas with high soil resistivity and southwest areas with complex terrains. The grounding body is used as a core component for lightning protection and fault current discharge of a power grid, and the size parameter of the grounding body directly determines whether the impact grounding resistance meets the standard or not, so that the safe and stable operation of the whole power system is affected. At present, 1000kV extra-high voltage alternating current and +/-800 kV extra-high voltage direct current transmission projects in China are operated in a large scale, a transmission line pole tower is broken through by 100 meters in height, a lightning current peak value to be born by a single-base pole tower grounding device can reach more than 50kA, according to the standard of DL/T621-1997 grounding of alternating current electric devices, the design requirement of impact grounding resistance is generally lower than 10 omega, under the extreme working condition, the pole tower pile foundation external cage type grounding body has the advantages of high current dissipation efficiency, good foundation cooperativity and the like, and becomes the main stream grounding form of an extra-high voltage and new energy power station pole tower, the rationality of the size design is directly related to whether grounding performance meets the standard, the requirement of impact grounding resistance is ensured through accurate size parameters, and engineering economy is considered to avoid material waste. However, the existing size design method of the cage type grounding body for the tower pile foundation mainly adopts a forward trial calculation mode of presetting size parameters firstly, then calculating impact grounding resistance to verify whether the impact grounding resistance reaches the standard, and is influenced by multi-factor coupling such as soil resistivity, lightning current parameters, structural interaction and the like, the preset size parameters are often difficult to match target resistance once, key parameters are required to be repeatedly adjusted for recalculation, so that design efficiency is low, deviation rate with the target resistance is high, and suitability of the cage type structure grounding body for the tower pile foundation for the external application is reduced. Disclosure of Invention The invention provides a method and a system for designing the size of a grounding body of a cage structure for external application of a tower pile foundation, which solve the technical problems that the existing method for designing the size of the grounding body of the cage structure for external application of the tower pile foundation mainly adopts a forward trial calculation mode of presetting size parameters and then calculating whether an impact grounding resistance is up to standard or not, is influenced by multi-factor coupling such as soil resistivity, lightning current parameters, structural interaction and the like, the preset size parameters are often difficult to match a target resistance at one time, key parameters need to be repeatedly adjusted and recalculated, so that the design efficiency is low, the deviation rate with the target resistance is high, and the suitability of the grounding body of the cage structure for external application of the tower pile foundation is reduced. The invention provides a method for designing the size of a grounding body of a tower pile foundation external application cage structure, which comprises the following steps: Obtaining a design basic parameter and a target impulse grounding resistance of a grounding body of the tower pile foundation external application cage structure, and carrying out equivalent resistance conversion according to the target impulse grounding resistance and the design basic parameter to obtain a corresponding equivalent power frequency grounding resistance; Performing critical dimension back calculation according to the design basic parameters based on the equivalent power frequency grounding resistance and a preset resistance contribution ratio to obtain corresponding critical structural dimension pa