CN-122017502-A - Method and system for calculating insulation level of ultra-high voltage combined electrical apparatus based on X-ray

CN122017502ACN 122017502 ACN122017502 ACN 122017502ACN-122017502-A

Abstract

The invention discloses an insulation level calculating method and system of an ultra-high voltage combined electrical apparatus based on X-rays, wherein the method comprises the steps of obtaining partial discharge voltage of an ultra-high voltage GIS operation withstand voltage test, calculating electric field strength through electric field simulation under a charge condition, and calculating the minimum insulation level when the ultra-high voltage GIS operation withstand voltage test is just operated by combining the partial discharge voltage after actual temperature correction; setting X-ray parameters to irradiate and excite the GIS, obtaining corresponding partial discharge voltage, if the partial discharge voltage is smaller than the voltage during operation, combining the X-ray parameters, the change rule of discharge charges in the solid insulation and the photoionization action parameters to deduce the minimum insulation level of the solid insulation containing the defects, and finally calculating the insulation level reduction amplitude. The method realizes unified insulation level calculation of SF 6 gas and solid insulation, quantitatively obtains the reduction amplitude, accurately captures insulation weak links, provides reliable basis for GIS health diagnosis and life prediction, and ensures safe and stable operation of the power system.

Inventors

WU SHIYOU
HUO YUPENG
GONG ZHENZHOU
YAN WENQING
CHENG MENGYING
Min Hongmao
LAI XINHUI
XIAO LIRONG
DING DENGWEI
ZHENG SHUSHENG

Assignees

国网江西省电力有限公司南昌供电分公司
国网江西省电力有限公司
国网江西省电力有限公司电力科学研究院
清华四川能源互联网研究院
华北电力大学

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (10)

1. The method for calculating the insulation level of the ultra-high voltage combined electrical apparatus based on the X-rays is characterized by comprising the following steps of: Step S1, obtaining partial discharge voltage of an ultra-high voltage GIS when the ultra-high voltage GIS is put into operation to perform a withstand voltage test, calculating electric field strength through electric field simulation, correcting the electric field strength according to the current actual temperature and air pressure conditions, and calculating the minimum insulation level of the ultra-high voltage GIS when the ultra-high voltage GIS is just put into operation based on the corrected electric field strength and the partial discharge voltage during the withstand voltage test; Step S2, setting X-ray parameters and irradiating an excited ultrahigh voltage GIS to obtain partial discharge voltage under X-ray irradiation excitation, and if the partial discharge voltage under the X-ray irradiation excitation is smaller than the partial discharge voltage during operation withstand voltage test, deducing the minimum insulation level of the ultrahigh voltage GIS solid insulation defect under the X-ray irradiation according to the partial discharge voltage under the X-ray irradiation excitation and the X-ray parameters; and step S3, calculating the reduction amplitude of the ultra-high voltage GIS insulation level based on the minimum insulation level of the ultra-high voltage GIS during operation and the minimum insulation level of the ultra-high voltage GIS solid insulation defect under X-ray irradiation.
2. The method for calculating the insulation level of the ultra-high voltage combined electrical apparatus based on the X-rays, which is characterized by adopting an electric field simulation method under the condition of containing charges to calculate the electric field intensity, wherein the simulation method is developed by combining the correlation relationship of electric displacement, charge density, electric field intensity, electric potential, ground potential, standard dielectric constant and relative dielectric constant, and then correcting the electric field intensity obtained by simulation according to the current actual temperature and air pressure conditions.
3. The method for computing insulation level of an ultra-high voltage combined electrical apparatus based on X-rays according to claim 2, wherein the method is characterized in that the method is based on the corrected electric field strength and partial discharge voltage at the time of withstand voltage test Calculating minimum insulation level of ultra-high voltage GIS (gas insulated switchgear) during operation The specific process of the method comprises extracting SF 6 gas and solid insulated along-plane actual electric field strength from the electric field strength corrected by the ultra-high voltage GIS Taking the actual electric field intensity of the SF 6 gas and solid insulated surface and the partial discharge voltage during operation withstand voltage test The minimum value of the ratio is used as the minimum insulation level of the ultra-high voltage GIS when the ultra-high voltage GIS is just put into operation 。
4. The method for computing insulation level of ultra-high voltage combined electrical apparatus based on X-ray as set forth in claim 3, wherein the specific process of step S2 is to set X-ray parameters and irradiate excitation ultra-high voltage GIS to obtain partial discharge voltage under X-ray irradiation excitation Partial discharge voltage under excitation of X-ray irradiation Partial discharge voltage at the time of withstand voltage test with operation To judge the size of (1), if Calculating the actual electric field intensity of the SF 6 gas and solid insulated surface and the partial discharge voltage under the excitation of X-ray irradiation according to the method of the step S1 The minimum value of the ratio is taken as the insulation level of SF 6 gas and solid insulation along the surface under the irradiation of X-rays Simultaneously combining the charge change rule of the internal discharge of the solid insulation and the related parameters of the X-ray photoionization to deduce the final electric field strength, thereby calculating the minimum insulation level of the solid insulation Taking out And (3) with Is used as the minimum insulation level of the ultra-high voltage GIS solid insulation defect under the irradiation of X rays 。
5. The method for computing insulation level of ultra-high voltage combined electrical apparatus based on X-ray as set forth in claim 4, wherein the specific process of deriving final electric field strength by simultaneously combining charge change rule of internal discharge of solid insulation and related parameters of X-ray photoionization comprises minimum insulation level of solid insulation The related parameters of the charge equation include electron number density, positive ion number density, negative ion number density, electron mobility, positive ion mobility, electron diffusion coefficient, positive ion diffusion coefficient, negative ion diffusion coefficient, impact ionization coefficient, electron attachment coefficient, positive ion-electron recombination coefficient, positive ion recombination coefficient, element charge, standard dielectric constant, relative dielectric constant, potential gradient, i.e. electric field strength, electric field strength formed by electric charge, describing the change rule of the number of positive ions, negative ions and electrons by the related parameters of the charge equation, and combining partial discharge voltage under X-ray irradiation excitation And meanwhile, the photoionization of X rays is characterized by combining a conversion coefficient, an X-ray dose, a gas density and a gas effective ionization volume.
6. The method for calculating the insulation level of an ultra-high voltage combined electrical apparatus based on X-rays as set forth in claim 5, wherein the minimum insulation level of solid insulation is calculated Based on the obtained partial discharge voltage under the excitation of X-ray irradiation And final electric field strength by taking partial discharge voltage under X-ray irradiation excitation Minimum value of ratio to final electric field intensity, and minimum insulation level of solid insulation is calculated 。
7. The method for calculating the insulation level of the ultra-high voltage combined electrical apparatus based on the X rays, which is characterized in that the specific process for calculating the reduction amplitude of the insulation level of the ultra-high voltage GIS based on the minimum insulation level of the ultra-high voltage GIS when just put into operation and the minimum insulation level of the ultra-high voltage GIS under the irradiation of the X rays is that the reduction amplitude of the insulation level of the ultra-high voltage GIS is obtained by calculating the ratio of the difference value of the minimum insulation level of the ultra-high voltage GIS when just put into operation and the minimum insulation level of the ultra-high voltage GIS under the irradiation of the X rays and converting the ratio into a percentage form.
8. An insulation level calculating system for an extra-high voltage combined electrical apparatus based on X-rays, for executing the insulation level calculating method for an extra-high voltage combined electrical apparatus based on X-rays as set forth in any one of claims 1 to 7, comprising: The minimum insulation level calculation module is used for obtaining partial discharge voltage of the ultra-high voltage GIS when the ultra-high voltage GIS is put into operation and is subjected to a withstand voltage test, electric field strength is calculated through electric field simulation, the electric field strength is corrected according to the current actual temperature and air pressure conditions, and the minimum insulation level of the ultra-high voltage GIS when the ultra-high voltage GIS is just put into operation is calculated based on the corrected electric field strength and the partial discharge voltage when the ultra-high voltage GIS is put into operation; The system comprises an X-ray irradiation ultra-high voltage GIS solid insulation defect-containing minimum insulation level calculation module, a power supply module and a power supply module, wherein the X-ray irradiation ultra-high voltage GIS solid insulation defect-containing minimum insulation level calculation module is used for setting X-ray parameters and irradiating and exciting the ultra-high voltage GIS to obtain partial discharge voltage under X-ray irradiation excitation; the extra-high voltage GIS insulation level reduction amplitude calculation module is used for calculating the reduction amplitude of the extra-high voltage GIS insulation level based on the minimum insulation level of the extra-high voltage GIS during operation and the minimum insulation level of the extra-high voltage GIS solid insulation containing defects under X-ray irradiation.
9. An electronic device comprising a processor, a memory and a bus, said processor and said memory being connected by said bus, wherein said memory is adapted to store a set of program code, said processor being adapted to invoke said program code stored in said memory for performing the X-ray based method of calculating the insulation level of an extra-high voltage combiner according to any of claims 1-7.
10. A non-volatile computer storage medium having stored thereon computer executable instructions for performing the X-ray based insulation level calculating method of an extra-high voltage electrical combiner according to any one of claims 1 to 7.

Description

Method and system for calculating insulation level of ultra-high voltage combined electrical apparatus based on X-ray Technical Field The invention relates to the technical field of ultra-high voltage combined electrical appliances, in particular to an insulation level calculating method and system of an ultra-high voltage combined electrical appliance based on X rays. Background The ultra-high voltage combined electrical apparatus (GIS) is a key component in an electric power system, the internal structure is complex, parts are more, the requirement on the insulation level is higher, the internal solid insulation and the gas insulation are required to bear very high voltage, and the insulation level is probably greatly reduced due to a small defect, so that accurate calculation of the insulation level has important significance. Patent publication No. CN111308279a discloses a method for calculating the insulation strength of high-voltage electrical equipment based on gas decomposition products, which obtains the insulation strength by calculating the gas decomposition products in the partial discharge process, but the method aims at gas insulation, gas insulation and solid insulation in GIS, and is difficult to realize by a method for calculating a specific reaction process. The SF 6 gas insulation and solid insulation of the whole air chamber are required to be uniformly calculated for the insulation level calculation of the GIS, and after the insulation level is obtained, important references can be provided for the health diagnosis and life prediction of the GIS, so that the safe and stable operation of the GIS is ensured. Partial discharges of insulators in GIS can be excited by X-rays, but are not currently applied to insulation level calculations. Therefore, a unified insulation level calculation method for GIS gas insulation and solid insulation is urgently needed. Disclosure of Invention Aiming at the defects of the prior art, the invention provides an insulation level calculation method of an ultra-high voltage combined electrical apparatus based on X-rays, which aims to realize unified insulation level calculation of gas insulation and solid insulation of the whole gas chamber of an ultra-high voltage GIS, obtain a more accurate insulation level result and provide important references for health diagnosis and life prediction of the GIS. In order to achieve the purpose, the invention provides the technical scheme that the method for calculating the insulation level of the ultra-high voltage combined electrical apparatus based on X-rays comprises the following steps: Step S1, obtaining partial discharge voltage of an ultra-high voltage GIS when the ultra-high voltage GIS is put into operation to perform a withstand voltage test, calculating electric field strength through electric field simulation, correcting the electric field strength according to the current actual temperature and air pressure conditions, and calculating the minimum insulation level of the ultra-high voltage GIS when the ultra-high voltage GIS is just put into operation based on the corrected electric field strength and the partial discharge voltage during the withstand voltage test; Step S2, setting X-ray parameters and irradiating an excited ultrahigh voltage GIS to obtain partial discharge voltage under X-ray irradiation excitation, and if the partial discharge voltage under the X-ray irradiation excitation is smaller than the partial discharge voltage during operation withstand voltage test, deducing the minimum insulation level of the ultrahigh voltage GIS solid insulation defect under the X-ray irradiation according to the partial discharge voltage under the X-ray irradiation excitation and the X-ray parameters; and step S3, calculating the reduction amplitude of the ultra-high voltage GIS insulation level based on the minimum insulation level of the ultra-high voltage GIS during operation and the minimum insulation level of the ultra-high voltage GIS solid insulation defect under X-ray irradiation. Further, an electric field simulation method under the condition of containing electric charges is adopted to calculate the electric field intensity, the simulation method is developed by combining the correlation relation of electric displacement, electric charge density, electric field intensity, electric potential, ground potential, standard dielectric constant and relative dielectric constant, and then the electric field intensity obtained through simulation is corrected according to the current actual temperature and air pressure conditions. Further, based on the corrected electric field strength and the partial discharge voltage at the time of the withstand voltage testCalculating minimum insulation level of ultra-high voltage GIS (gas insulated switchgear) during operationThe specific process of the method comprises extracting SF 6 gas and solid insulated along-plane actual electric field strength from the electric field