CN116298719A

CN116298719A - Equipment insulation aging identification method and device, electronic equipment and storage medium

Info

Publication number: CN116298719A
Application number: CN202310106870.6A
Authority: CN
Inventors: 乔峰; 田洪; 钮恒; 黄潺凯; 阙盛华; 刘鑫铭; 张乐
Original assignee: Xiamen Shangwei Intelligent Power Technology Co ltd
Current assignee: Xiamen Shangwei Intelligent Power Technology Co ltd
Priority date: 2023-02-10
Filing date: 2023-02-10
Publication date: 2023-06-23

Abstract

The application provides a device insulation aging identification method, a device, electronic equipment and a storage medium, and relates to the technical field of electrical equipment safety evaluation. The method comprises the steps of combining a target discharge signal value of a current detection period with target discharge signal values of historical detection periods corresponding to the current detection period, and referring to a standard deviation of signals, so that an insulation aging stage of equipment is determined. The discharge signal value sampled by the current detection period and the historical detection period corresponding to the current detection period is comprehensively analyzed to serve as the insulation aging judgment basis of the current detection period, so that the problem that the insulation aging analysis result is high in randomness caused by taking the sampling data of the current detection period or the sampling data of a single moment in the current detection period as the judgment basis is avoided, the problem that insulation aging judgment cannot be carried out when signal missing detection occurs is avoided, and the accuracy and the reliability of the equipment insulation aging analysis result are improved.

Description

Equipment insulation aging identification method and device, electronic equipment and storage medium

Technical Field

The application relates to the technical field of electrical equipment safety evaluation, in particular to an equipment insulation aging identification method, an equipment insulation aging identification device, electronic equipment and a storage medium.

Background

When the insulator in the high-voltage electric equipment has defects, partial discharge phenomenon can be generated under the action of high voltage. The insulation aging stage can be identified by monitoring the partial discharge data, so that the method can be used for carrying out safety early warning on the use state of the electrical equipment.

In the prior art, the partial discharge value of an insulator acquired in real time is compared with the aging rule of the insulator measured based on an offline test, and the aging stage of the insulator in the current state is judged.

However, since the insulator is intermittently partially discharged at the initial stage of the insulation aging, there is a problem that the reliability of the insulation aging analysis result is poor when there is a partial discharge omission.

Disclosure of Invention

The present application aims to provide a device insulation aging identification method, device, electronic device and storage medium, so as to improve reliability of an insulation aging analysis result of an electrical device.

In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

in a first aspect, an embodiment of the present application provides a method for identifying insulation degradation of a device, including:

the acquisition equipment samples the sequence of partial discharge signals in the current detection period;

determining a target discharge signal value of the current detection period according to the partial discharge signal sampling sequence of the current detection period;

determining a signal standard deviation according to the target discharge signal value of the current detection period and the target discharge signal value of each history detection period in a plurality of history detection periods before the current detection period;

and determining the current insulation aging stage of the equipment according to the target discharge signal value of the current detection period, the target discharge signal value of each historical detection period and the signal standard deviation.

Optionally, the determining the insulation aging stage where the device is currently located according to the target discharge signal value of the current detection period, the target discharge signal value of each historical detection period, and the signal standard deviation includes:

generating a fitting curve according to the target discharge signal value of the current detection period and the target discharge signal values of the historical detection periods;

Generating an insulation aging index corresponding to the current detection period according to the target discharge signal value of the current detection period, the signal standard deviation and the slope of the fitting curve;

and determining the current insulation aging stage of the equipment according to the insulation aging index corresponding to the current detection period.

Optionally, the generating the insulation aging index corresponding to the current detection period according to the target discharge signal value of the current detection period, the signal standard deviation, and the slope of the fitted curve includes:

determining an absolute value of a difference value between a target discharge signal value of the current detection period and the signal standard deviation;

and determining the product of the absolute value of the difference value and the slope of the fitted curve as an insulation aging index corresponding to the current detection period.

Optionally, determining, according to the insulation aging index corresponding to the current detection period, an insulation aging stage where the device is currently located includes:

if the insulation aging index is smaller than or equal to a first preset threshold value, determining that the equipment is currently in a discharge initial period of insulation aging;

if the insulation aging index is larger than the first preset threshold value and smaller than or equal to a second preset threshold value, determining that the equipment is currently in the stable period of insulation aging;

If the insulation aging index is larger than the second preset threshold value and smaller than or equal to a third preset threshold value, determining that the equipment is currently in an adjacent breakdown period of insulation aging;

and if the insulation aging index is larger than a third preset threshold value, determining that the equipment is currently in an accelerated degradation period of insulation aging.

determining a signal missing detection interval according to the signal standard deviation;

determining the number of target discharge signal values located in the signal missing detection interval in the target discharge signal values of the current detection period;

and if the number of the target discharge signal values in the signal omission interval meets a first preset condition, determining that the equipment is currently in the discharge initial period of insulation aging.

Optionally, the partial discharge signal sampling sequence of the acquisition device in the current detection period includes:

sampling partial discharge signals of a preset number of continuous power frequency periods in a current detection period according to a preset sampling frequency to obtain a partial discharge signal sampling sequence of the current detection period, wherein the partial discharge signal sampling sequence comprises sampling discharge signal values in each power frequency period, and the number of the sampling discharge signal values in each power frequency period is determined according to the preset sampling frequency and the power frequency period.

Optionally, the determining the target discharge signal value of the current detection period according to the partial discharge signal sampling sequence of the current detection period includes:

determining the maximum sampling discharge signal value under each power frequency period from the sampling discharge signal values under each power frequency period, and generating a to-be-selected discharge signal set according to the maximum sampling discharge signal value under each power frequency period;

determining a current maximum partial discharge signal value from the set of discharge signals to be selected;

judging whether the current maximum partial discharge signal value meets a second preset condition or not;

if yes, the current maximum partial discharge signal value is used as a target discharge signal value of the current detection period;

if not, the current maximum partial discharge signal value is removed from the to-be-selected discharge signal set to obtain a new to-be-selected discharge signal set, and the current new maximum partial discharge signal value is determined from the new to-be-selected discharge signal set; and circularly executing until the current new maximum partial discharge signal value meets the second preset condition, and determining the current new maximum partial discharge signal value as the target discharge signal value of the current detection period.

Optionally, the determining whether the current maximum partial discharge signal value meets a second preset condition includes:

determining a discharge signal mean value and a discharge signal standard deviation corresponding to the current detection period according to the maximum sampling discharge signal value under each power frequency period and the number of the power frequency periods in the current detection period;

determining a signal deviation range according to the discharge signal mean value and the discharge signal standard deviation;

and if the current maximum partial discharge signal value is in the signal deviation range, determining that the current maximum partial discharge signal value meets the condition.

In a second aspect, an embodiment of the present application further provides an apparatus for identifying insulation degradation of a device, including: the system comprises an acquisition module and a determination module;

the acquisition module is used for acquiring a partial discharge signal sampling sequence of the equipment in the current detection period;

the determining module is used for determining a target discharge signal value of the current detection period according to the partial discharge signal sampling sequence of the current detection period;

the determining module is used for determining a signal standard deviation according to the target discharge signal value of the current detection period and the target discharge signal value of each history detection period in a plurality of history detection periods before the current detection period;

The determining module is used for determining the current insulation aging stage of the equipment according to the target discharge signal value of the current detection period, the target discharge signal values of each historical detection period and the signal standard deviation.

Optionally, the determining module is specifically configured to generate a fitting curve according to the target discharge signal value of the current detection period and the target discharge signal values of each historical detection period;

Optionally, the determining module is specifically configured to determine an absolute value of a difference between the target discharge signal value of the current detection period and the signal standard deviation;

Optionally, the determining module is specifically configured to determine that the device is currently in a discharge start period of insulation aging if the insulation aging index is less than or equal to a first preset threshold;

Optionally, the determining module is specifically configured to determine a signal missing detection interval according to the signal standard deviation;

Optionally, the collecting module is specifically configured to sample partial discharge signals of a preset number of continuous power frequency periods in a current detection period according to a preset sampling frequency, obtain a partial discharge signal sampling sequence of the current detection period, where the partial discharge signal sampling sequence includes sampling discharge signal values in each power frequency period, and the number of sampling discharge signal values in each power frequency period is determined according to the preset sampling frequency and the power frequency period.

Optionally, the determining module is specifically configured to determine a maximum sampling discharge signal value under each power frequency period from the sampling discharge signal values under each power frequency period, and generate a set of to-be-selected discharge signals according to the maximum sampling discharge signal value under each power frequency period;

Optionally, the determining module is specifically configured to determine, according to a maximum sampling discharge signal value in each power frequency period and the number of power frequency periods in the current detection period, a discharge signal mean value and a discharge signal standard deviation corresponding to the current detection period;

In a third aspect, an embodiment of the present application provides an electronic device, including: a processor, a storage medium, and a bus, the storage medium storing machine-readable instructions executable by the processor, the processor and the storage medium in communication over the bus when the electronic device is operating, the processor executing the machine-readable instructions to perform the steps of the device insulation degradation identification method as provided in the first aspect when executed.

In a fourth aspect, embodiments of the present application provide a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of the device insulation degradation identification method as provided in the first aspect.

The beneficial effects of this application are:

the application provides a device insulation aging identification method, a device, an electronic device and a storage medium. The discharge signal value sampled by the current detection period and the historical detection period corresponding to the current detection period is comprehensively analyzed to serve as the insulation aging judgment basis of the current detection period, so that the problem that the insulation aging analysis result is high in randomness caused by taking the sampling data of the current detection period or the sampling data of a single moment in the current detection period as the judgment basis is avoided, the problem that insulation aging judgment cannot be carried out when signal missing detection occurs is avoided, and the accuracy and the reliability of the equipment insulation aging analysis result are improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic flow chart of an equipment insulation aging identification method provided in an embodiment of the present application;

fig. 2 is a flow chart of another method for identifying insulation aging of equipment according to an embodiment of the present application;

fig. 3 is a schematic flow chart of another method for identifying insulation degradation of equipment according to an embodiment of the present application;

fig. 4 is a flow chart of another method for identifying insulation degradation of equipment according to an embodiment of the present application;

fig. 5 is a schematic flow chart of another method for identifying insulation degradation of equipment according to an embodiment of the present application;

fig. 6 is a flow chart of another method for identifying insulation degradation of equipment according to an embodiment of the present application;

fig. 7 is a schematic diagram of an apparatus for identifying insulation degradation of a device according to an embodiment of the present application;

Fig. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it should be understood that the accompanying drawings in the present application are only for the purpose of illustration and description, and are not intended to limit the protection scope of the present application. In addition, it should be understood that the schematic drawings are not drawn to scale. A flowchart, as used in this application, illustrates operations implemented according to some embodiments of the present application. It should be understood that the operations of the flow diagrams may be implemented out of order and that steps without logical context may be performed in reverse order or concurrently. Moreover, one or more other operations may be added to the flow diagrams and one or more operations may be removed from the flow diagrams as directed by those skilled in the art.

In addition, the described embodiments are only some, but not all, of the embodiments of the present application. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, are intended to be within the scope of the present application.

It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the presence of the features stated hereinafter, but not to exclude the addition of other features.

First, the related background art of the present solution will be described, and when there is a defect in an insulator in a high-voltage electrical apparatus, a partial discharge phenomenon occurs under the action of a high voltage. With the increase of the running time, the insulation material is gradually deteriorated under the action of discharge, so that defects further develop to finally cause complete insulation failure, and the intensity of partial discharge in the process is correspondingly changed. Research shows that after the electric equipment with insulation defects is powered on in operation, the partial discharge change is subjected to a process of descending, basically stabilizing, rising again and stabilizing again, which can be called as a discharge start period, a stabilizing period, an accelerated degradation period and an adjacent breakdown period, and finally the discharge intensity of the accelerated degradation device continuously rises to generate thorough breakdown and insulation failure. This process usually requires a long time to elapse and the identification of the insulation aging stage can theoretically be achieved by analyzing the data recorded by the partial discharge on-line monitoring device during the process.

However, the number and the scale of switch cabinets of a power distribution system are huge, and most of the switch cabinets in operation have no function of on-line monitoring of partial discharge. In order to realize the partial discharge monitoring of the switch cabinet, the partial discharge on-line monitoring device can be attached to the outside of the original switch cabinet only in an external mode, and power is supplied by a built-in battery of the switch cabinet. The partial discharge on-line monitoring device can only detect in an intermittent detection mode, and a longer time interval exists between the two detection modes, so that the energy consumption is reduced as much as possible, the battery replacement period is prolonged, the possibility of missed detection is also caused, especially in the early stage of defect generation in the switch cabinet, the partial discharge itself also occurs intermittently, and the probability of missed detection is relatively high.

Regarding the processing and analysis technology of the partial discharge on-line monitoring data, on one hand, the current method does not process the problem that the intermittent partial discharge on-line monitoring data may have missed detection, so that in a common data processing algorithm, the missed detection data often causes larger conclusive change, for example, in a moving average algorithm, one-time missed detection may cause larger deviation of a moving average; on the other hand, the method for identifying the degradation stage of the insulator by utilizing the partial discharge on-line monitoring information is less, wherein the main idea is to compare the aging rule of the insulator of the type based on the current partial discharge data measured through an off-line test, or to add a pattern identification algorithm to carry out qualitative analysis on the type of the insulation defect, but because the current measurement result is only analyzed, the influence of randomness is larger, the reliability of conclusion is in doubt, the degradation stage of the insulator in the switch cabinet is difficult to judge, and the suggestion on operation and maintenance work and even investment replacement planning cannot be given.

Based on the method, the equipment degradation analysis applicable to the intermittent partial discharge detection scene is provided, the equipment degradation index at the current moment is determined based on the collected current partial discharge data and the collected historical partial discharge data, and the problem that the equipment degradation identification reliability is poor due to the fact that degradation judgment is carried out only through the current partial discharge data and accurate analysis cannot be carried out under the condition of missing detection is avoided.

Fig. 1 is a schematic flow chart of an equipment insulation aging identification method provided in an embodiment of the present application; the execution subject of the method may be a computer, a server, or other electronic device with a data processing function, as shown in fig. 1, and the method may include:

s101, collecting partial discharge signal sampling sequences of equipment in the current detection period.

The device can refer to high-voltage electrical equipment, such as a switch cabinet, and the insulator in the electrical equipment generates partial discharge phenomenon under the action of high voltage, so that the partial discharge on-line monitoring device can collect partial discharge signal sampling sequences of the current detection period in real time.

The partial discharge is detected in the unit of period, so that the problem that the analysis result caused by the analysis and calculation by only collecting the discharge signal at a single moment is not convincing can be avoided.

S102, determining a target discharge signal value of the current detection period according to the partial discharge signal sampling sequence of the current detection period.

Alternatively, the target discharge signal value of the current detection period may be determined from a plurality of discharge signal values included in the collected partial discharge signal sampling sequence of the current detection period, where the selected target discharge signal value may be a representative discharge signal value in the current detection period, and in some embodiments, a maximum discharge signal value of the current detection period may be selected as the target discharge signal value.

S103, determining a signal standard deviation according to the target discharge signal value of the current detection period and the target discharge signal value of each history detection period in a plurality of history detection periods before the current detection period.

The plurality of history detection periods here may be a plurality of history detection periods adjacent to the current detection period. For example: if the partial discharge is continuously detected according to the period T, the sampling sequence of the first detection period, the sampling sequence of the second detection period, the sampling sequence of the third detection period and the sampling sequence of the nth detection period can be obtained respectively.

And if the nth sensing period is the current sensing period, the plurality of history periods before the current sensing period may include: the n-1 detection period, the n-2 detection period and the n-3 detection period are selected, and the history detection period adjacent to the current detection period is selected, so that the selected history detection period has continuity with the partial discharge signal value of the current detection period and can be better used for analyzing the current detection period, and when the selected history detection period is far away from the current detection period, the data continuity is poor, the data acquisition time interval is far away, and the method is less persuasive when the selected history detection period is used for evaluating the partial discharge of the current detection period.

Alternatively, the target discharge signal values of each historical detection period may also be determined separately, so that, according to the target discharge signal value of the current detection period and the target discharge signal value of each historical detection period corresponding to the current detection period, a signal standard deviation may be determined, and the signal standard deviation may represent the overall standard deviation of all the discharge signal values sampled in the current detection period and each historical detection period.

S104, determining the current insulation aging stage of the equipment according to the target discharge signal value of the current detection period, the target discharge signal value of each historical detection period and the standard deviation of the signals.

In some embodiments, the insulation aging stage in which the device is currently located may be calculated based on the obtained target discharge signal value of the current detection period, the target discharge signal value of each historical detection period, and the standard deviation of the signals obtained by the calculation, so that based on the insulation aging stage in which the device is located, it may be determined whether to repair or replace the insulator in the device, so that the electrical device may be continuously maintained in efficient operation.

In summary, according to the method for identifying insulation aging of equipment provided in this embodiment, the insulation aging stage where the equipment is currently located is determined by combining the target discharge signal value of the current detection period and the target discharge signal value of each historical detection period corresponding to the current detection period, and referring to the standard deviation of the signals. The discharge signal value sampled by the current detection period and the historical detection period corresponding to the current detection period is comprehensively analyzed to serve as the insulation aging judgment basis of the current detection period, so that the problem that the insulation aging analysis result is high in randomness caused by taking the sampling data of the current detection period or the sampling data of a single moment in the current detection period as the judgment basis is avoided, the problem that insulation aging judgment cannot be carried out when signal missing detection occurs is avoided, and the accuracy and the reliability of the equipment insulation aging analysis result are improved.

Optionally, in step S101, the sampling sequence of the partial discharge signal of the collecting device in the current detection period may include: and sampling partial discharge signals of a preset number of continuous power frequency periods in the current detection period according to a preset sampling frequency to obtain a partial discharge signal sampling sequence of the current detection period, wherein the partial discharge signal sampling sequence comprises sampling discharge signal values under each power frequency period, and the number of the sampling discharge signal values under each power frequency period is determined according to the preset sampling frequency and the power frequency period.

In one implementation manner, the detection of the partial discharge of the device may be performed according to a preset sampling period, where the detection of the partial discharge may be performed every T hours, where the partial discharge signals of n power frequency periods may be sampled according to a preset application frequency f in each detection period T, so as to obtain a partial discharge signal sampling sequence of each detection period.

Taking the current detection period as an example, sampling partial discharge signals of n continuous power frequency periods with f as frequency, and sampling each power frequency periodm points, the sampled value can be noted as: s is(s) _ij I= … n, j= … m, the sampling time interval between every two sampling points is Δt, and f _p Is the power frequency (in China electric network f) _p =50), then f=mf _p ，Δt＝1/50。

By the sampling mode, the partial discharge signal sampling sequence corresponding to the current detection period can be obtained, and the partial discharge signal sampling sequence can comprise: { s ₁₁ ，s ₁₂ ，s ₁₃ …s _1m ，s ₂₁ ，s ₂₂ ，s ₂₃ …s _nm }。

Optionally, the same sampling manner may be used for each historical detection period before the current detection period, so as to obtain a partial discharge signal sampling sequence of each historical detection period.

Fig. 2 is a flow chart of another method for identifying insulation aging of equipment according to an embodiment of the present application; optionally, in step S102, determining the target discharge signal value of the current detection period according to the partial discharge signal sampling sequence of the current detection period may include:

s201, determining the maximum sampling discharge signal value under each power frequency period from the sampling discharge signal values under each power frequency period, and generating a to-be-selected discharge signal set according to the maximum sampling discharge signal value under each power frequency period.

According to the above description, it can be known that m sampling discharge signal values can be obtained in each power frequency period, and the maximum sampling discharge signal value in each power frequency period can be extracted as the discharge maximum value in each power frequency period, denoted as s _i S is then _i ＝max _j＝1……m (s _ij )。

And forming a discharge signal set to be selected by the maximum sampling discharge signal value extracted in each power frequency period.

S202, determining the current maximum partial discharge signal value from the set of the discharge signals to be selected.

Further, the current maximum value is determined from the maximum sampling discharge signal values of each power frequency period contained in the to-be-selected discharge signal set to be used as the current maximum partial discharge signal value.

S203, judging whether the current maximum partial discharge signal value meets a second preset condition.

In view of the time required for the development and change of the insulation defect, it can be approximately considered that the maximum value of the sampling value of each period is subject to normal distribution in each detection, and in consideration of the sampling error possibly caused by the sampling field environment, the current maximum partial discharge signal value can be subjected to outlier identification by adopting the principle of 3 in the embodiment so as to judge whether the current maximum partial discharge signal value meets the second preset condition.

And S204, if yes, taking the current maximum partial discharge signal value as a target discharge signal value of the current detection period.

If the current maximum partial discharge signal value meets the second preset condition, the current maximum partial discharge signal value can be determined as the target discharge signal value of the current detection period.

S205, if not, removing the current maximum partial discharge signal value from the to-be-selected discharge signal set to obtain a new to-be-selected discharge signal set, and determining the current new maximum partial discharge signal value from the new to-be-selected discharge signal set; and circularly executing until the current new maximum partial discharge signal value meets a second preset condition, and determining the current new maximum partial discharge signal value as a target discharge signal value of the current detection period.

If the current maximum partial discharge signal value does not meet the second preset condition, the current maximum partial discharge signal value can be removed from the to-be-selected discharge signal set, and the maximum sampling discharge signal value is selected from the maximum sampling discharge signal values in the residual power frequency periods in the to-be-selected discharge signal set again to serve as the current new maximum partial discharge signal value.

And continuously judging whether the current new maximum partial discharge signal value meets a second preset condition, circulating until the maximum partial discharge signal value meeting the second preset condition is determined, stopping execution, and determining the maximum partial discharge signal value meeting the second preset condition as a target discharge signal value of the current detection period.

Fig. 3 is a schematic flow chart of another method for identifying insulation degradation of equipment according to an embodiment of the present application; optionally, in step S203, determining whether the current maximum partial discharge signal value meets the second preset condition may include:

s301, determining a discharge signal mean value and a discharge signal standard deviation corresponding to a current detection period according to the maximum sampling discharge signal value under each power frequency period and the number of the power frequency periods in the current detection period.

Assume that the maximum sampling discharge signal value under each power frequency period is s _i Indicating that the number of power frequency periods is n, then the formula can be used

Calculating to obtain a discharge signal average value corresponding to the current detection period, wherein when i=1, s is ₁ Represents the maximum sampling discharge signal value under the 1 st power frequency period, s when i=2 ₂ Represents the maximum sampling discharge signal value under the 2 nd power frequency period, s when i=n _n And the maximum sampling discharge signal value under the nth power frequency period is represented.

The standard deviation of the discharge signal corresponding to the current detection period can be

S302, determining a signal deviation range according to the mean value of the discharge signals and the standard deviation of the discharge signals.

Based on this, when outlier recognition is performed using the 3σ (three times standard deviation) principle ", a range of signal deviation is obtained

The present invention is not limited to the 3 sigma principle, and flexible adjustment of the suitability is possible, for example, the 2 sigma principle can be adopted.

S303, if the current maximum partial discharge signal value is within the signal deviation range, determining that the current maximum partial discharge signal value meets the condition.

For the selected current maximum partial discharge signal value, it can be judgedWhether or not to belong to

When belonging to->

When the current maximum partial discharge signal value can be determined to meet the second preset condition, the current maximum partial discharge signal value can be determined to be the target discharge signal value of the current detection period.

If the current maximum partial discharge signal value does not belong to

And then removing the discharge signal from the set of discharge signals to be selected.

It should be noted that, when the number of the power frequency periods n is 1, the maximum sampling discharge signal value in the power frequency period can be determined as the target discharge signal value of the current detection period without performing outlier identification.

Based on the above steps, the target discharge signal value of the current detection period, which may also be referred to as the discharge signal maximum value s of the current detection period, is obtained _max 。

Similarly, the target discharge signal value for each historical detection period can be calculated by referring to the determination mode of the target discharge signal value of the current detection period. And will not be described in detail here.

Through the above sampling and calculating process, for each detection, even if no discharge signal is detected in a part of the power frequency period, the target discharge signal value s of the detection period obtained by the final calculation _max The effect of (2) is also small. That is, the target discharge signal value s of the detection period can still be accurately obtained for intermittent partial discharge _max 。

Fig. 4 is a flow chart of another method for identifying insulation degradation of equipment according to an embodiment of the present application; optionally, in step S104, determining the insulation aging stage in which the device is currently located according to the target discharge signal value of the current detection period, the target discharge signal value of each historical detection period, and the signal standard deviation may include:

s401, generating a fitting curve according to the target discharge signal value of the current detection period and the target discharge signal value of each historical detection period.

Assume that target discharge signal values s of the current detection period are obtained respectively _max And a target discharge signal value s for K-1 historical detection periods preceding the current detection period _max Thus obtaining K s _max According to K s _max The number of detections is linearly fitted, i.e. the number of detections from the installation of the partial discharge on-line monitoring device is taken as the independent variable x, s _max Performing least square fitting on the dependent variable y according to a linear model y=ax+b, and calculating the slope a of a fitted curve;

s402, generating an insulation aging index corresponding to the current detection period according to the target discharge signal value, the signal standard deviation and the slope of the fitting curve of the current detection period.

Then, the target discharge signal value s can be determined according to the current detection period _max And the slope a of the fitting curve is combined with the standard deviation of the signal to calculate and obtain the insulation aging index DET corresponding to the current detection period.

The standard deviation of the signals is calculated as follows: according to the obtained K s _max Can adopt the formula

Calculating to obtain the mean value of the discharge signal, and then according to +.>

Using the formula

And calculating to obtain the standard deviation of the signal.

S403, determining the current insulation aging stage of the equipment according to the insulation aging index corresponding to the current detection period.

Optionally, based on the insulation aging index corresponding to the calculated current detection period, the insulation aging stage of the device at the current time can be judged.

Because the insulation aging index corresponding to the current detection period is comprehensively calculated according to the current detection period and each sampling discharge signal value in the historical detection period before the current detection period, the insulation aging index is not only determined according to the unique discharge value at the current detection moment, the randomness of the insulation aging index obtained by calculation is avoided, and the insulation aging index has more analysis significance.

Optionally, in step S402, generating the insulation aging index corresponding to the current detection period according to the target discharge signal value, the signal standard deviation, and the slope of the fitted curve in the current detection period may include: determining an absolute value of a difference value between a target discharge signal value and a signal standard deviation in a current detection period; and determining the product of the absolute value of the difference value and the slope of the fitted curve as an insulation aging index corresponding to the current detection period.

In one implementation, the calculation formula for the insulation aging index may be defined as follows:

DET＝a|s _max,0 -D _max |

wherein:

s _max,0 target discharge signal value s for the current detection period _max I.e. the target discharge signal value s of the current detection period _max ；SD _max For the current detection period and the target discharge signal value s of each history detection period _max Standard deviation of samples, i.e. K s _max Is a standard deviation of signals of (a).

Fig. 5 is a schematic flow chart of another method for identifying insulation degradation of equipment according to an embodiment of the present application; optionally, in step S403, determining, according to the insulation aging index corresponding to the current detection period, the insulation aging stage in which the device is currently located may include:

s501, if the insulation aging index is smaller than or equal to a first preset threshold value, determining that the equipment is currently in a discharge initial period of insulation aging.

In one mode, the first preset threshold values can be respectively set-T _th1 A second preset threshold DET _th2 And a third preset threshold DET _th3 。

If the insulation aging index DET of the current detection period is less than or equal to-T _th1 When the equipment is in the initial discharge period of insulation aging, the equipment discharge s in the initial discharge period can be determined _max Gradually weakening and fluctuating up and down from a larger value.

S502, if the insulation aging index is larger than a first preset threshold value and smaller than or equal to a second preset threshold value, determining that the equipment is currently in the stable period of insulation aging.

If the insulation aging index of the current detection period is-T _th1 <ET≤DET _th2 When the equipment is in the stable period of insulation aging, the discharge s of the equipment in the stable period is determined _max Relatively small and substantially stable.

S503, if the insulation aging index is larger than the second preset threshold value and smaller than or equal to the third preset threshold value, determining that the equipment is currently in the adjacent breakdown period of insulation aging.

If the insulation aging index DET of the current detection period _th2 <ET≤DET _th3 When the device is in the adjacent breakdown period of insulation aging, determining the discharge s of the device in the adjacent breakdown period _max The discharge amplitude remains unchanged within a certain range of the higher level.

S504, if the insulation aging index is larger than a third preset threshold value, determining that the equipment is currently in an accelerated degradation period of insulation aging.

If the insulation aging index DET of the current detection period>DET _th3 When the equipment is in the accelerated degradation period of insulation aging, the discharge s of the equipment in the accelerated degradation period is determined _max The onset of the gradual increase, typically, is substantially comparable to the time from the onset to the breakdown from this state.

Wherein, -DET in one possible way of value _th1 ＝-0.24，DET _th2 ＝0.03，DET _th3 ＝0.9。

In another way, the first preset threshold DET can be set respectively _th1 A second preset threshold DET _th2 And a third preset threshold DET _th3 。

Then, DET.ltoreq. -DET _th1 When the device is in the discharge initial period; -DET _th1 <DET≤DET _th2 When the equipment is in a stable period; DET (DET) _th2 <DET≤DET _th3 The device is in an adjacent breakdown period; DET (DET)>DET _th3 The device is in an accelerated degradation period.

It is noted that in the definition of DET, a is the slope, and a is close to 0 in the vicinity of the breakdown period, and that although smax minus SDmax is relatively large, it is also relatively small after multiplication by a number close to 0, but will be larger than the stationary period because the slope in the stationary period is small and smax-SDmax is also small.

The slope a is significantly greater than zero during the accelerated degradation period, so multiplying smax minus the absolute value of SDmax is greater than during the near breakdown period.

The insulation aging index is calculated to determine the insulation aging stage of the equipment, and an additional determination mode of the discharge initial period can be given below based on the special condition of missed detection.

Fig. 6 is a flow chart of another method for identifying insulation degradation of equipment according to an embodiment of the present application; optionally, in step S403, determining the insulation aging stage in which the device is currently located according to the target discharge signal value of the current detection period, the target discharge signal value of each historical detection period, and the signal standard deviation may include:

s601, determining a signal missing detection interval according to the signal standard deviation.

In general, when the detection of the Kth detection fails, the target discharge signal value of the Kth detection period approaches 0, i.e. s _max,k 0, since the signal amplitude at the time of detecting partial discharge is far greater than the background interference amplitude at the time of omission, then 0, SD _max ]As a signal missing section, missing detection judgment is performed. And when s is _max,i >SD _max A partial discharge signal is considered to be detected. Wherein SD is _max Refers to the standard deviation of the signal.

S602, determining the target discharge signal value of the current detection period and the number of target discharge signal values in the signal missing detection interval among the target discharge signal values of each historical detection period.

Alternatively, based on the determined signal omission interval, K s of the target discharge signal value of the current detection period and the target discharge signal value of each history detection period may be determined _max Middle position [0, SD ] _max ]The number of target discharge signal values of the interval, i.e. K s, are determined _max The number of the detected values is determined to be the missing detection value.

S603, if the number of target discharge signal values in the signal missing detection interval meets a first preset condition, determining that the equipment is currently in a discharge initial period of insulation aging.

When the number of the target discharge signal values in the signal missing detection interval meets a first preset condition, the current discharge starting period of the equipment in insulation aging can be directly determined. Wherein the first preset condition may refer to K/2, i.e. K s _max S in the signal missing detection interval _max When the number of (2) is greater than or equal to K/2, it can be determined that the device is currently in the discharge initiation period of insulation aging. Where K is as described above, and refers to the number of periods of the current detection period and the historical detection period.

Optionally, based on the identification of the current insulation aging stage of the equipment, the equipment maintenance or replacement can be performed timely by operators, and the safety of equipment use is ensured.

The following describes a device, an apparatus, a storage medium, etc. for executing the device insulation aging identification method provided in the present application, and specific implementation processes and technical effects of the device insulation aging identification method are referred to above, which are not described in detail below.

Fig. 7 is a schematic diagram of an apparatus insulation aging identification apparatus according to an embodiment of the present application, where functions implemented by the apparatus insulation aging identification apparatus correspond to steps executed by the method. The apparatus may be understood as a computer, a server, or a processor of a server, or may be understood as a component, which is independent from the server or the processor and performs the functions of the present application under the control of the server, as shown in fig. 7, where the apparatus may include: the acquisition module 710 and the determination module 720;

the acquisition module 710 is configured to acquire a partial discharge signal sampling sequence of the device in a current detection period;

a determining module 720, configured to determine a target discharge signal value of the current detection period according to the partial discharge signal sampling sequence of the current detection period;

a determining module 720, configured to determine a signal standard deviation according to the target discharge signal value of the current detection period and the target discharge signal value of each of a plurality of history detection periods before the current detection period;

The determining module 720 is configured to determine, according to the target discharge signal value of the current detection period, the target discharge signal value of each historical detection period, and the standard deviation of the signal, an insulation aging stage in which the device is currently located.

Optionally, the determining module 720 is specifically configured to generate a fitting curve according to the target discharge signal value of the current detection period and the target discharge signal value of each historical detection period;

generating an insulation aging index corresponding to the current detection period according to the target discharge signal value, the signal standard deviation and the slope of the fitting curve of the current detection period;

Optionally, the determining module 720 is specifically configured to determine an absolute value of a difference between the target discharge signal value and the signal standard deviation in the current detection period;

Optionally, the determining module 720 is specifically configured to determine that the device is currently in a discharge start period of insulation aging if the insulation aging index is less than or equal to a first preset threshold;

if the insulation aging index is larger than the first preset threshold value and smaller than or equal to the second preset threshold value, determining that the equipment is currently in the stable period of insulation aging;

If the insulation aging index is larger than the second preset threshold value and smaller than or equal to the third preset threshold value, determining that the equipment is currently in the adjacent breakdown period of insulation aging;

Optionally, the determining module 720 is specifically configured to determine a signal missing detection interval according to a signal standard deviation;

determining the target discharge signal value of the current detection period and the number of target discharge signal values in the signal missing detection interval among the target discharge signal values of each historical detection period;

if the number of the target discharge signal values in the signal missing detection interval meets a first preset condition, determining that the equipment is currently in a discharge initial period of insulation aging.

Optionally, the acquisition module 710 is specifically configured to sample partial discharge signals of a preset number of continuous power frequency periods in a current detection period according to a preset sampling frequency, and obtain a partial discharge signal sampling sequence of the current detection period, where the partial discharge signal sampling sequence includes sampling discharge signal values in each power frequency period, and the number of sampling discharge signal values in each power frequency period is determined according to the preset sampling frequency and the power frequency period.

Optionally, the determining module 720 is specifically configured to determine a maximum sampling discharge signal value under each power frequency period from the sampling discharge signal values under each power frequency period, and generate a set of to-be-selected discharge signals according to the maximum sampling discharge signal value under each power frequency period;

determining a current maximum partial discharge signal value from a set of discharge signals to be selected;

if yes, taking the current maximum partial discharge signal value as a target discharge signal value of the current detection period;

if not, removing the current maximum partial discharge signal value from the to-be-selected discharge signal set to obtain a new to-be-selected discharge signal set, and determining the current new maximum partial discharge signal value from the new to-be-selected discharge signal set; and circularly executing until the current new maximum partial discharge signal value meets a second preset condition, and determining the current new maximum partial discharge signal value as a target discharge signal value of the current detection period.

Optionally, the determining module 720 is specifically configured to determine, according to the maximum sampling discharge signal value in each power frequency period and the number of power frequency periods in the current detection period, a discharge signal mean value and a discharge signal standard deviation corresponding to the current detection period;

Determining a signal deviation range according to the mean value of the discharge signal and the standard deviation of the discharge signal;

The foregoing apparatus is used for executing the method provided in the foregoing embodiment, and its implementation principle and technical effects are similar, and are not described herein again.

The above modules may be one or more integrated circuits configured to implement the above methods, for example: one or more application specific integrated circuits (Application Specific Integrated Circuit, abbreviated as ASIC), or one or more microprocessors (digital singnal processor, abbreviated as DSP), or one or more field programmable gate arrays (Field Programmable Gate Array, abbreviated as FPGA), or the like. For another example, when a module above is implemented in the form of a processing element scheduler code, the processing element may be a general-purpose processor, such as a central processing unit (Central Processing Unit, CPU) or other processor that may invoke the program code. For another example, the modules may be integrated together and implemented in the form of a system-on-a-chip (SOC).

The modules may be connected or communicate with each other via wired or wireless connections. The wired connection may include a metal cable, optical cable, hybrid cable, or the like, or any combination thereof. The wireless connection may include a connection through a LAN, WAN, bluetooth, zigBee, or NFC, or any combination thereof. Two or more modules may be combined into a single module, and any one module may be divided into two or more units. It will be clearly understood by those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described system and apparatus may refer to corresponding procedures in the method embodiments, which are not described in detail in this application.

Fig. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present application, where the device may be a computing device with a data processing function.

The device comprises: a processor 801, and a storage medium 802.

The storage medium 802 is used to store a program, and the processor 801 calls the program stored in the storage medium 802 to execute the above-described method embodiment. The specific implementation manner and the technical effect are similar, and are not repeated here.

In which the storage medium 802 stores program code that, when executed by the processor 801, causes the processor 801 to perform various steps in the device insulation degradation identification method according to various exemplary embodiments of the present application described in the section of the "exemplary method" described above in the present specification.

The processor 801 may be a general purpose processor such as a Central Processing Unit (CPU), digital signal processor (Digital Signal Processor, DSP), application specific integrated circuit (Application Specific Integrated Circuit, ASIC), field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, and may implement or perform the methods, steps, and logic blocks disclosed in embodiments of the present application. The general purpose processor may be a microprocessor or any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present application may be embodied directly in a hardware processor for execution, or in a combination of hardware and software modules in the processor for execution.

The storage medium 802 is a non-volatile computer-readable storage medium that can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. The storage medium may include at least one type of storage medium, and may include, for example, flash Memory, a hard disk, a multimedia card, a card-type storage medium, a random access storage medium (Random Access Memory, RAM), a static random access storage medium (Static Random Access Memory, SRAM), a programmable Read-Only storage medium (Programmable Read Only Memory, PROM), a Read-Only storage medium (ROM), a charged erasable programmable Read-Only storage medium (Electrically Erasable Programmable Read-Only storage), a magnetic storage medium, a magnetic disk, an optical disk, and the like. A storage medium is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to such. The storage medium 802 in the embodiments of the present application may also be a circuit or any other device capable of implementing a storage function, for storing program instructions and/or data.

Optionally, the present application also provides a program product, such as a computer readable storage medium, comprising a program for performing the above-described method embodiments when being executed by a processor.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in hardware plus software functional units.

The integrated units implemented in the form of software functional units described above may be stored in a computer readable storage medium. The software functional unit is stored in a storage medium, and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (english: processor) to perform part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: u disk, mobile hard disk, read-Only Memory (ROM), random access Memory (Random Access Memory, RAM), magnetic disk or optical disk, etc.

Claims

1. A method for identifying insulation degradation of a device, comprising:

2. The method of claim 1, wherein determining the insulation aging stage in which the device is currently located based on the target discharge signal value for the current detection period, the target discharge signal values for each historical detection period, and the signal standard deviation comprises:

3. The method of claim 2, wherein generating the insulation aging index corresponding to the current detection period according to the target discharge signal value of the current detection period, the signal standard deviation, and the slope of the fitted curve comprises:

4. The method of claim 2, wherein determining the insulation aging stage in which the device is currently located according to the insulation aging index corresponding to the current detection period comprises:

5. The method of claim 1, wherein determining the insulation aging stage in which the device is currently located based on the target discharge signal value for the current detection period, the target discharge signal values for each historical detection period, and the signal standard deviation comprises:

6. The method of claim 1, wherein the sequence of partial discharge signal samples at the current detection period by the acquisition device comprises:

7. The method of claim 6, wherein said determining a target discharge signal value for the current detection period from the sequence of partial discharge signal samples for the current detection period comprises:

8. The method of claim 7, wherein said determining whether the current maximum partial discharge signal value meets a second preset condition comprises:

9. An apparatus for identifying insulation degradation of a device, comprising: the system comprises an acquisition module and a determination module;

10. An electronic device, comprising: a processor, a storage medium and a bus, the storage medium storing program instructions executable by the processor, the processor and the storage medium communicating via the bus when the electronic device is running, the processor executing the program instructions to perform the steps of the device insulation degradation identification method according to any one of claims 1 to 8 when executed.

11. A computer-readable storage medium, characterized in that the storage medium has stored thereon a computer program which, when executed by a processor, performs the steps of the device insulation degradation identification method according to any one of claims 1 to 8.