CN-121980196-A - Ring main unit gas box laser welding seam tightness detection method and system

CN121980196ACN 121980196 ACN121980196 ACN 121980196ACN-121980196-A

Abstract

The invention relates to the technical field of weld tightness detection, in particular to a method and a system for detecting weld tightness of ring main unit gas tank laser welding, wherein the method comprises the steps of constructing an original time sequence response sequence of weld tightness; the method comprises the steps of presetting a time length, dividing the whole detection process into a plurality of end-to-end continuous analysis time periods to form a weld dynamic evolution characteristic sequence, acquiring evolution stages of each continuous time period according to the weld dynamic evolution characteristic sequence of each continuous time period, identifying key turning sections for converting latent defects of the weld into dominant defects by analyzing state transition and continuous characteristic changes of each segmentation unit, and determining a reinspection trigger point. The invention can carry out structural segmentation treatment on the weld tightness change, establish a complete defect evolution model, effectively characterize the continuous response and the microcrack delay opening trend of the hidden defect, and remarkably improve the defect identification precision and sensitivity compared with the prior art.

Inventors

ZHAO RUIQI
SHI LANG
QIAN JIANGQI
ZHOU HUABIN
YU JIANFENG
LIU GENGSHENG
WANG ZHI
WANG HUATIAN
LI ZHIYONG
ZHANG SHUANGXIONG
DAI SHOUXIANG
WU XIAOYANG
HUANG NINGNING

Assignees

南京海兴电网技术有限公司

Dates

Publication Date: 20260505
Application Date: 20260403

Claims (14)

1. The method for detecting the tightness of the laser welding seam of the ring main unit gas tank is characterized by comprising the following steps: Acquiring whole-course time sequence tightness response data of a weld joint of a ring main unit to be detected under a preset pressurizing process, synchronously acquiring intra-cavity pressure variation, leakage response quantity in unit time and pressure maintaining attenuation quantity at each sampling time according to a unified time reference, and constructing a weld joint tightness original time sequence response sequence; Dividing the whole detection process into a plurality of end-to-end continuous analysis time periods by presetting the time length, extracting leakage response increment, response inversion times, pressure disturbance following amplitude and pressure maintaining stage delay release quantity in each continuous time period based on the original time sequence response sequence of the weld joint tightness, and forming a weld joint dynamic evolution characteristic sequence; According to the dynamic evolution characteristic sequence of the welding seam of each continuous period, the evolution stages of each continuous period are obtained, and the continuous periods in the same evolution stage are combined, so that a plurality of evolution segmentation units are obtained; And (3) identifying key turning sections for converting the latent defects of the welding line into dominant defects by analyzing state transition and continuous characteristic change of each evolution segmentation unit, and determining a recheck trigger point.
2. The method for detecting tightness of laser welding seams of ring main unit gas tank according to claim 1, wherein the method for collecting pressure maintaining attenuation is characterized by selecting pressure maintaining starting time after a preset pressurizing process enters a pressure maintaining stage Corresponding intra-cavity pressure values As the pressure maintaining reference pressure, and continuously collecting each sampling moment in the pressure maintaining stage Corresponding intra-cavity pressure values And then the pressure attenuation degree of the current sampling moment is represented by the difference value between the pressure maintaining reference pressure and the pressure value in the cavity at the current sampling moment, and the pressure maintaining attenuation amount corresponding to each sampling moment is obtained 。
3. The method for detecting tightness of laser welding seams of ring main unit gas tank according to claim 1, wherein the extraction method of leakage response increment is as follows for any continuous period of time =[ , Reading the initial sampling time of the continuous period Corresponding leakage response per unit time And ending the sampling time Corresponding leakage response per unit time And obtaining continuous time period by the difference of leakage response amounts of unit time corresponding to the front and rear end points Corresponding leakage response delta 。
4. The method for detecting the tightness of the laser welding seam of the ring main unit gas tank according to claim 1, wherein the method for extracting the response inversion times is aimed at any continuous time period =[ , Firstly, calculating differential signs of leakage response quantity in unit time between adjacent sampling moments in the continuous time period, counting the number of times of changing from positive to negative and from negative to positive of adjacent differential signs in the continuous time period, and defining the number of times of changing as the continuous time period Corresponding response inversion times 。
5. The method for detecting the tightness of the laser welding seam of the ring main unit gas tank according to claim 1, wherein the extraction method of the pressure disturbance following amplitude is aimed at any continuous time period =[ , Extracting intra-cavity pressure variation sequence and leakage response sequence in unit time in the continuous time period, calculating synchronous response proportion of leakage response in unit time relative to intra-cavity pressure variation at each sampling time, and taking average absolute value of all synchronous response proportion in the continuous time period to obtain continuous time period Corresponding pressure disturbance following amplitude 。
6. The method for detecting the tightness of the laser welding seam of the ring main unit gas tank according to claim 1, wherein the method for extracting the delayed release of the pressure maintaining stage is characterized by obtaining a set of continuous time periods corresponding to the pressure maintaining stage and the continuous time periods corresponding to any pressure maintaining stage =[ , Within ], extracting a pressure maintaining attenuation amount sequence and a leakage response amount sequence per unit time, and then during the continuous period In the method, the initial sampling time when the pressure maintaining attenuation quantity enters a low-change state is determined based on the pressure maintaining attenuation quantity change difference value corresponding to the adjacent sampling time At the time of determining the initial sampling time Then, extracting from the initial sampling time To the continuous period Ending the sampling time A subsequent response portion between which the leakage response amount per unit time is continuously increased, and comparing the subsequent response portion with the initial sampling time An accumulated increment corresponding to the leakage response quantity per unit time is defined as the continuous period And the corresponding delay release amount in the pressure maintaining stage.
7. The method for detecting tightness of laser welding seams of ring main unit gas tank according to claim 6, wherein the method for determining the initial sampling time when the pressure maintaining attenuation amount enters the low variation state is that if the pressure maintaining attenuation amount variation differences in the continuous K sampling intervals are smaller than the preset attenuation threshold value, the initial sampling time of the continuous K sampling intervals is determined as the initial sampling time of the low variation state 。
8. The method for detecting tightness of laser welding seams of ring main unit gas tank according to claim 1, wherein the evolution stage comprises an initial closing stage, a delay expansion stage and a penetration forming stage.
9. The method for detecting tightness of laser welding seams of a ring main unit gas tank according to claim 1, wherein the method for acquiring evolution stages of each continuous period comprises the following steps: Inputting the obtained continuous-period weld dynamic evolution characteristic sequence into a pre-constructed evolution stage prediction model, and outputting the continuous-period evolution stage labels, so as to obtain the evolution stages of the continuous periods.
10. The method for detecting tightness of laser welding seams of a ring main unit gas box according to claim 1, wherein the method for acquiring key turning sections comprises the following steps: reading the segmentation results of each evolution segmentation unit and extracting unit characteristic parameters; Identifying the position from the initial closing stage to the hysteresis expansion stage and from the hysteresis expansion stage to the through formation stage, and determining the connection position of the first change of the evolution stage label between adjacent evolution segmentation units as a candidate state transition boundary; extracting weld dynamic evolution feature sequences corresponding to a preset number of continuous time periods before and after each candidate state transition boundary, and calculating transition feature parameters; And acquiring turning intensity coefficients of each candidate state transition boundary, determining a connection position corresponding to the candidate state transition boundary as a key turning boundary when the turning intensity coefficients are larger than or equal to a preset turning threshold value, and determining a front and rear segmentation interval connected by the corresponding key turning boundary as a key turning section.
11. The method for detecting the tightness of the welding seam of the ring main unit gas tank laser welding according to claim 10, wherein the unit characteristic parameters comprise a start sampling time, an end sampling time, an evolution stage label and a welding seam dynamic evolution characteristic sequence corresponding to each continuous period in the corresponding evolution segmentation unit; The transfer characteristic parameters comprise leakage response increment before and after the boundary, response inversion times, pressure disturbance following amplitude and change amplitude of hysteresis release quantity in the pressure maintaining stage.
12. The method for detecting the tightness of the laser welding seam of the ring main unit gas tank according to claim 10, wherein the method for determining the recheck trigger point comprises the following steps: Obtaining local characteristic change intensity sequences of each continuous period of the key turning section, and calculating a reinspection trigger intensity value of each continuous period; sequencing the continuous time periods according to the repeated detection trigger intensity values, constructing a candidate set, selecting the corresponding time of the continuous time period with the maximum repeated detection trigger intensity value in the candidate set as an initial target repeated detection trigger point, and acquiring a corresponding evolution stage type; If the initial target recheck trigger point is located in the hysteresis expansion stage, determining the initial target recheck trigger point as a final recheck trigger point; otherwise, eliminating from the candidate set, and sequentially selecting the next time period according to the sequence of the retest trigger intensity values until an initial target retest trigger point in a hysteresis expansion stage is obtained and is used as a final retest trigger point.
13. The method for detecting the tightness of the laser welding seam of the ring main unit gas tank according to claim 12, wherein the method for obtaining the local characteristic change strength sequence corresponding to each continuous period in the key turning section comprises the steps of calculating the change amplitude of leakage response increment, response inversion times, pressure disturbance following amplitude and delay release amount in the pressure maintaining stage between adjacent continuous periods, and time-aligning each change amplitude to obtain the local characteristic change strength sequence.
14. A ring main unit gas box laser welding seam tightness detection system for implementing the ring main unit gas box laser welding seam tightness detection method according to any of claims 1-13, characterized in that the system comprises: The data acquisition module acquires the whole-course time sequence tightness response data of the welding seam of the ring main unit gas box to be detected under the preset pressurizing process, synchronously acquires the intra-cavity pressure variation, the leakage response quantity in unit time and the pressure maintaining attenuation quantity at each sampling time according to the unified time standard, and constructs a welding seam tightness original time sequence response sequence; the characteristic extraction module is used for presetting the time length, dividing the whole detection process into a plurality of end-to-end continuous analysis time periods, and extracting leakage response increment, response inversion times, pressure disturbance following amplitude and pressure maintaining stage delayed release quantity in each continuous time period based on the weld joint tightness original time sequence to form a weld joint dynamic evolution characteristic sequence; The stage identification module is used for acquiring evolution stages of each continuous period according to the dynamic evolution characteristic sequences of the welding lines of each continuous period, and combining the continuous periods in the same evolution stage so as to acquire a plurality of evolution segmentation units; and the rechecking triggering module is used for identifying key turning sections for converting the latent defects of the welding line into the dominant defects by analyzing state transition and continuous characteristic change of each evolution segmentation unit and determining rechecking triggering points.

Description

Ring main unit gas box laser welding seam tightness detection method and system Technical Field The invention relates to the technical field of weld tightness detection, in particular to a method and a system for detecting weld tightness of ring main unit gas tank laser welding. Background The ring main unit is used as key switch equipment in a power distribution system, and the gas tank of the ring main unit is usually welded by laser to form continuous sealing weld joints so as to ensure internal insulation performance and long-term operation safety. However, due to factors such as welding thermal cycle, uneven molten pool flow, and material structure differences, latent defects such as microcracks, quasi-closed pore chains, or local unfused areas may exist in the weld. The existing ring main unit gas box tightness detection method is mainly judged by final values of pressurization, pressure maintaining and leakage, only the weld defects with dominant leakage can be identified, and continuous response changes of the weld defects in the detection process are difficult to be described. Particularly for latent defects, the latent defects may not have obvious leakage at the initial detection stage, are activated only at the initial stage of specific pressure disturbance or pressure maintaining stage, and then the leakage response may tend to be stable, for example, defect units originally in a quasi-closed state may be communicated under the specific pressure disturbance, so that the interior of a welding line gradually forms an actual leakage path, and therefore, the conventional method is easy to miss detection or misjudgment. Further, the prior art lacks dynamic feature extraction and segmentation analysis capability of continuous detection data of the welding seam, and is difficult to identify that the welding seam is in different evolution stages such as initial closure, hysteresis expansion or penetration formation, and the key turning section of the transformation from the latent defect to the dominant defect cannot be accurately identified, and further quantization basis cannot be provided for a rechecking trigger point, so that even if a detection system acquires a dynamic signal, the whole process dynamic assessment of the sealing performance of the welding seam is difficult to realize, and the rechecking strategy lacks pertinence and efficiency. Disclosure of Invention In order to solve the problems, the invention provides a ring main unit gas box laser welding seam tightness detection method and system. The invention adopts the following technical scheme that the method for detecting the tightness of the laser welding seam of the ring main unit gas tank comprises the following steps: Acquiring whole-course time sequence tightness response data of a weld joint of a ring main unit to be detected under a preset pressurizing process, synchronously acquiring intra-cavity pressure variation, leakage response quantity in unit time and pressure maintaining attenuation quantity at each sampling time according to a unified time reference, and constructing a weld joint tightness original time sequence response sequence; Dividing the whole detection process into a plurality of end-to-end continuous analysis time periods by presetting the time length, extracting leakage response increment, response inversion times, pressure disturbance following amplitude and pressure maintaining stage delay release quantity in each continuous time period based on the original time sequence response sequence of the weld joint tightness, and forming a weld joint dynamic evolution characteristic sequence; According to the dynamic evolution characteristic sequence of the welding seam of each continuous period, the evolution stages of each continuous period are obtained, and the continuous periods in the same evolution stage are combined, so that a plurality of evolution segmentation units are obtained; And (3) identifying key turning sections for converting the latent defects of the welding line into dominant defects by analyzing state transition and continuous characteristic change of each evolution segmentation unit, and determining a recheck trigger point. As a further description of the above technical solution, the method for collecting the pressure-maintaining attenuation amount includes selecting a pressure-maintaining start time after a preset pressurizing process enters a pressure-maintaining stageCorresponding intra-cavity pressure valuesAs the pressure maintaining reference pressure, and continuously collecting each sampling moment in the pressure maintaining stageCorresponding intra-cavity pressure valuesAnd then the pressure attenuation degree of the current sampling moment is represented by the difference value between the pressure maintaining reference pressure and the pressure value in the cavity at the current sampling moment, and the pressure maintaining attenuation amount corresponding to each sampling moment i