阅读说明：本技术 一种变压器的湿度状态智能控制方法 (Intelligent control method for humidity state of transformer ) 是由 陈欢 李有明 郭伟强 于 2019-03-18 设计创作，主要内容包括：本发明提供了一种变压器的湿度状态智能控制方法,通过网络客户端登录云服务器的管理界面；在每个小时划分的若干周期内定时采集电力变压器呼吸器的湿度值、温度值、气体流量值的模拟量值,并将其转化为数字量值后上传至云服务器,同时采集电力变压器呼吸器的图像信息,并将其上传至云服务器；云服务器根据所接收的图像进行数字化处理,并对温度、湿度、气体流量、图像数值进行梯度值计算并判断,将结果显示在监控终端的界面上；控制变色硅胶加热器启动或者关闭。该方法能使湿度状态监测更加精准,防止误判,提高了变压器呼吸器的可靠性和寿命,同时减少了维护所需的人力和物力。(The invention provides an intelligent control method for the humidity state of a transformer, which logs in a management interface of a cloud server through a network client; acquiring analog quantity values of a humidity value, a temperature value and a gas flow value of the power transformer respirator at regular time in a plurality of periods divided every hour, converting the analog quantity values into digital quantity values, uploading the digital quantity values to a cloud server, and acquiring image information of the power transformer respirator and uploading the image information to the cloud server; the cloud server carries out digital processing according to the received image, carries out gradient value calculation and judgment on the temperature, the humidity, the gas flow and the image numerical value, and displays the result on an interface of the monitoring terminal; and controlling the color-changing silica gel heater to be started or closed. The method can enable the humidity state to be monitored more accurately, prevent misjudgment, improve the reliability and the service life of the transformer respirator and reduce manpower and material resources required by maintenance.)

1. The intelligent control method for the humidity state of the transformer is characterized by comprising the following steps of:

step 1, logging in a management interface of a cloud server through a network client;

step 2, collecting analog quantity values of a humidity value, a temperature value and a gas flow value of the power transformer respirator regularly within a plurality of periods divided every hour, converting the analog quantity values into digital quantity values, uploading the digital quantity values to a cloud server, and collecting image information of the power transformer respirator regularly within the plurality of periods divided every hour and uploading the image information to the cloud server;

step 3, the cloud server carries out digital processing according to the received image, carries out gradient value calculation and judgment on the temperature, the humidity, the gas flow and the image numerical value, and displays the result on an interface of the monitoring terminal;

and 4, controlling the color-changing silica gel heater to be started or closed.

2. The intelligent humidity state control method for transformer according to claim 1, wherein said method for regularly collecting humidity value, temperature value, analog quantity value of gas flow value and image information of power transformer respirator in several periods divided every hour:

a cycle a is divided into different time windows, at a first time t at the beginning of each time window_hAnd a second time t_h+1Obtaining the temperature theta of the transformer respirator₁、θ₂Obtaining the humidity value m of the transformer respirator₁、m₂Obtaining the gas flow value p output by the transformer respirator₁、p₂To shoot transformer respirator image I₁、I₂。

3. The intelligent humidity state control method of transformer according to claim 1, wherein the method for the cloud server to perform digital processing according to the received transformer-respirator image comprises Canny detection operator edge extraction of the image of the allochroic silica gel range in the transformer-respirator and two-dimensional histogram processing according to HSV color space to obtain the blue-to-pink numerical ratio I₁’、I₂’。

4. The intelligent control method for the humidity state of the transformer according to claim 3, wherein the method for performing the two-dimensional histogram processing on the allochroic silica gel picture according to the HSV color space comprises the steps of performing color statistics on two dimensions of the Hue-Hue and the Saturation-Saturation according to the HSV color space and three dimensions of the transformer respirator area image, namely Hue-Hue, Saturation-Saturation and Value-lightness, drawing a two-dimensional histogram, and obtaining a detection result according to the proportion of blue to pink.

5. The intelligent control method for the humidity state of the transformer according to claim 1, wherein the cloud server is used for calculating the gradient values of the temperature, the humidity, the gas flow and the image numerical values:

1) according to the relation theta₂-θ₁Determining a temperature gradient d θ/dt;

2) according to the relation m₂-m₁Determining the humidity gradient dm/dt;

3) according to the relation p₂-p₁Determining the gradient dp/dt of the gas flow rate;

4) according to the relation I₂’-I₁' dI '/dt determines the gradient of color numerical ratio dI '/dt.

6. The intelligent control method for the humidity state of the transformer according to claim 1, wherein the method for judging the temperature, the humidity, the gas flow and the image numerical value comprises the following steps:

1) then repeating such measurements and gradient formation for the same time window in x-1 subsequent cycles a and uploading to the cloud server, storing for each cycle a-1, a-2.. a-x-1 those time windows for which the two or more numerical gradients are greater than or equal to 0;

2) in another cycle a ═ x check: whether at least z associated identical stored time windows exist in each preceding period a-1, a-2.. a-x-1, over which two or more gradient values are greater than or equal to 0;

3) if the time window of the previous period is consistent with the time window of the previous period, the cloud server sends a control signal to the allochroic silicagel heater in the period a which is x, and the allochroic silicagel heater enters an automatic heating mode after receiving the control signal; if not, the automatic heating mode is turned off and another period a + x 1 is counted for comparison.

7. The intelligent humidity state control method for a transformer according to claim 6, wherein the color-changing silica gel heater further comprises a manual off-line heating mode, and the manual off-line heating mode is used for starting heating the color-changing silica gel heater when the system is stopped for a period of time.

8. The intelligent humidity state control method for transformer according to claim 2 or 6, wherein the period a comprises 60 minutes, i.e. data storage is performed every 60 minutes.

9. Method for intelligent control of the state of humidity of a transformer according to claim 6, characterized in that said value of x is 4, i.e. the associated, same time window is checked in the following fourth cycle after storing all time windows of the three cycles a.

10. Method according to claim 6, characterized in that z has a value of 4, i.e. at least four associated, identical time windows are required for putting the heating means into operation.

Technical Field

The invention relates to the technical field of transformer control, in particular to an intelligent control method for the humidity state of a transformer.

Background

Currently, intelligent work on transformers is gaining attention. Along with the development of automation technology, the user also is higher and higher to the performance and the life-span requirement of transformer, and the service environment and the weather influence of transformer all can cause the power failure, and transformer class oil charge equipment is equipped with the respirator mostly, mainly has two aspect functions: firstly, air in the transformer body is communicated with outside air through a respirator, and when the internal transformer oil expands due to temperature rise, the internal gas is exhaled; when the internal transformer oil is cooled, external air is sucked, and the air pressure inside and outside the transformer body is always kept equal. And secondly, moisture in air entering the transformer is absorbed by the drying agent in the respirator, so that the insulating oil in the transformer keeps good electrical performance, and moist air is prevented from directly entering the transformer conservator to reduce or damage the insulating strength of the transformer. The respirator is installed at the tail end of a pipeline communicated with air, the inside of the pipeline is filled with an adsorbent, and the adsorbent is usually allochroic silica gel and has the functions of absorbing moisture in the air of the conservator, keeping the air in the conservator dry and preventing insulating oil of the transformer from being damped. When abnormal conditions such as serious color change of silica gel and the like occur in the operation of the respirator, the safe and reliable operation of the transformer is influenced, so that the maintenance work of the respirator is particularly important. The traditional mode for detecting whether the respirator has faults is that maintenance personnel go to the site to observe with naked eyes and judge through certain working experience, and multiple negligence and leaks can exist in the mode.

Disclosure of Invention

In view of this, the present invention is directed to provide an intelligent control method for a humidity state of a transformer, which can accurately monitor and adjust the humidity state of the transformer, and improve reliability and a service life of a transformer breather.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

an intelligent control method for the humidity state of a transformer comprises the following steps:

step 1, logging in a management interface of a cloud server through a network client;

step 2, collecting analog quantity values of a humidity value, a temperature value and a gas flow value of the power transformer respirator regularly within a plurality of periods divided every hour, converting the analog quantity values into digital quantity values, uploading the digital quantity values to a cloud server, and collecting image information of the power transformer respirator regularly within the plurality of periods divided every hour and uploading the image information to the cloud server;

step 3, the cloud server carries out digital processing according to the received image, carries out gradient value calculation and judgment on the temperature, the humidity, the gas flow and the image numerical value, and displays the result on an interface of the monitoring terminal;

and 4, controlling the color-changing silica gel heater to be started or closed.

The method for regularly acquiring the humidity value, the temperature value and the analog quantity value of the gas flow value of the power transformer respirator and acquiring the image information of the power transformer respirator in a plurality of periods divided every hour comprises the following steps:

a cycle a is divided into different time windows, at a first time t at the beginning of each time window_hAnd a second time t_h+1Obtaining the temperature value theta of the transformer respirator₁、θ₂Obtaining the humidity value m of the transformer respirator₁、m₂Obtaining the gas flow value p output by the transformer respirator₁、p₂To shoot transformer respirator image I₁、I₂。

Furthermore, the temperature value of the transformer respirator is collected by a distributed optical fiber temperature sensor, the humidity value of the transformer respirator is collected by a distributed optical fiber humidity sensor, and the distributed optical fiber temperature sensor and the distributed optical fiber humidity sensor are connected to the transformer respirator.

Further, the transformer gas flow value is collected by a flowmeter, and the flowmeter is connected to the transformer respirator and outputs the transformer gas flow value.

Further, the gas flow value, the temperature value and the humidity value of the transformer respirator can be converted into digital values from analog values.

Further, the images of the transformer respirator are collected by a remote camera arranged near the respirator.

The method for carrying out digital processing on the cloud server according to the received transformer respirator image comprises the steps of carrying out Canny detection operator edge extraction on the image of the allochroic silica gel range in the transformer respirator and carrying out two-dimensional histogram processing according to HSV color space to obtain the numerical ratio I of blue to pink₁’、I₂’。

Further, a specific method for extracting the edge matrix of the allochroic silica gel image by using a Canny detection operator comprises the following steps: reading RGB color values of an image; filtering the image by a Gaussian filter to eliminate noise in the image, and respectively carrying out differential calculation on each pixel in the edge of the image in the transverse direction and the longitudinal direction to obtain the amplitude and the direction of the gradient of the pixel; carrying out non-maximum suppression on the amplitude of the gradient of the pixel so as to highlight points with significant changes of intensity values in the neighborhood of the pixel, thereby obtaining a binary image of the image; and setting a high threshold and a low threshold to carry out edge detection and connection on the binary image so as to realize edge closure of the whole image of the binary image.

The method for processing the two-dimensional histogram of the allochroic silica gel picture according to the HSV color space comprises the steps of carrying out color statistics on two dimensions of the Hue-Hue and the Saturation-Saturation according to the Hue-Hue, the Saturation-Saturation and the Value-lightness of the transformer respirator region image according to the HSV color space, drawing a two-dimensional histogram, and obtaining a detection result according to the proportion of blue to pink.

The method for calculating the gradient value of the cloud server on the temperature, the humidity, the gas flow and the image numerical value comprises the following steps:

1) according to the relation theta₂-θ₁Determining one for d theta/dtTemperature gradient d θ/dt;

2) according to the relation m₂-m₁Determining the humidity gradient dm/dt;

3) according to the relation p₂-p₁Determining the gradient dp/dt of the gas flow rate;

4) according to the relation I₂’-I₁' dI '/dt determines the gradient of color numerical ratio dI '/dt.

Further, the method for judging the temperature, the humidity, the gas flow and the image value comprises the following steps:

1) then repeating such measurements and gradient formation for the same time window in x-1 subsequent cycles a and uploading to the cloud server, storing for each cycle a-1, a-2.. a-x-1 those time windows for which the two or more numerical gradients are greater than or equal to 0;

2) in another cycle a ═ x check: whether at least z associated identical stored time windows exist in each preceding period a-1, a-2.. a-x-1, over which two or more gradient values are greater than or equal to 0;

3) if the time window of the previous period is consistent with the time window of the previous period, the cloud server sends a control signal to the allochroic silicagel heater in the period a which is x, and the allochroic silicagel heater enters an automatic heating mode after receiving the control signal; if not, the automatic heating mode is turned off and another period a + x 1 is counted for comparison.

Preferably, the color-changing silica gel heater further comprises a manual off-line heating mode, and when the system is stopped for a period of time, the manual off-line heating mode is used for starting heating the color-changing silica gel heater.

Preferably, the period a comprises 60 minutes, i.e. data storage is performed every 60 minutes.

Preferably, the value of x is 4, i.e. after storing all time windows of the three periods a, the associated, same time window is checked in the fourth, following period.

Preferably, z has a value of 4, i.e. at least four associated, identical time windows are required for putting the heating device into operation.

Compared with the prior art, the intelligent control method for the humidity state of the transformer has the following beneficial effects:

(1) according to the intelligent control method for the humidity state of the transformer, the advanced sensing technology, the image acquisition technology and the cloud service technology are adopted, the intelligent control of the humidity state of the transformer is realized, and the investment of manpower and material resources required by maintenance is effectively reduced;

(2) according to the intelligent control method for the humidity state of the transformer, the humidity state of the transformer is controlled by multiple factors together, and a breather of the transformer is heated in time to dehumidify, so that the humidity state is monitored more accurately, and misjudgment is prevented;

(3) according to the intelligent control method for the humidity state of the transformer, the failure replacement frequency of the allochroic silicon is reduced, and the reliability and the service life of the transformer respirator are improved;

(4) the intelligent control method for the humidity state of the transformer can improve the insulativity of the transformer, improve the power supply reliability, reduce the faults of equipment caused by overhigh humidity and ensure the safe operation of the transformer.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a diagram illustrating steps of an intelligent humidity state control method for a transformer according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating steps for humidity value, temperature value, gas flow value, and image acquisition and data processing according to an embodiment of the present invention;

fig. 3 is a diagram illustrating a color histogram processing procedure according to an embodiment of the present invention.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The descriptions in this document referring to "first", "second", "upper", "lower", etc. are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," "upper," "lower," may explicitly or implicitly include at least one of the feature. In addition, the technical solutions in the embodiments may be combined with each other, but it is necessary that a person skilled in the art can realize the combination, and the technical solutions in the embodiments are within the protection scope of the present invention.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

The transformer generally all is provided with the respirator, carry out the dehumidification operation to the transformer, the transformer respirator of this embodiment is including being equipped with the moisture absorption device and the variable speed silica gel heater of silica gel that discolours, be provided with data acquisition module on the transformer respirator, data acquisition module includes distributed temperature sensor, humidity transducer, near remote camera of flowmeter and respirator, data acquisition module passes through the RS485 interface and is connected with central processing module, central processing module passes through the GPRS module with data, wireless network passes to cloud ware terminal with data and stores and handles, the realization is to the intelligent monitoring of transformer humidity state.

As shown in fig. 1, an intelligent control method for humidity state of a transformer includes the following steps:

step 1, logging in a management interface of a cloud server through a network client;

step 2, collecting analog quantity values of a humidity value, a temperature value and a gas flow value of the power transformer respirator regularly within a plurality of periods divided every hour, converting the analog quantity values into digital quantity values, uploading the digital quantity values to a cloud server, and collecting image information of the power transformer respirator regularly within the plurality of periods divided every hour and uploading the image information to the cloud server;

step 3, the cloud server carries out digital processing according to the received image, carries out gradient value calculation and judgment on the temperature, the humidity, the gas flow and the image numerical value, and displays the result on an interface of the monitoring terminal;

and 4, controlling the color-changing silica gel heater to be started or closed.

As shown in fig. 3, the cloud server performs the digital processing according to the received image as follows:

1) extracting a Canny detection operator from the transformer respirator picture, removing the environment, and extracting the color edge outline of the image in the color-changing silica gel area: reading RGB color values of an image; filtering the image by a Gaussian filter to eliminate noise in the image, and respectively carrying out differential calculation on each pixel in the edge of the image in the transverse direction and the longitudinal direction to obtain the amplitude and the direction of the gradient of the pixel; carrying out non-maximum suppression on the amplitude of the gradient of the pixel so as to highlight points with significant changes of intensity values in the neighborhood of the pixel, thereby obtaining a binary image of the image; and setting a high threshold and a low threshold to carry out edge detection and connection on the binary image so as to realize edge closure of the whole image of the binary image.

2) According to the HSV color space, the transformer respirator area image has three dimensions, namely Hue-Hue, Saturration-Saturation and Value-lightness, color statistics is carried out on the Hue-Hue and Saturration-Saturation two dimensions, a two-dimensional histogram is drawn, and the blue-pink numerical Value ratio I is obtained according to the two-dimensional histogram₁’、I₂’。

As shown in fig. 2, the steps of the humidity value, the temperature value, the gas flow value, and the image acquisition and data processing are as follows:

a cycle a is divided into different time windows, at a first time t at the beginning of each time window_hAnd a second time t_h+1In the embodiment, one cycle is 60 minutes, a is 1 hour, and each time window is divided into 1 minute at the first moment and 2 minutes at the second moment, and the transformer respirator temperature theta is obtained₁、θ₂Obtaining the humidity value m of the transformer respirator₁、m₂Obtaining the gas flow value p output by the transformer respirator₁、p₂Obtaining the color value I of the transformer respirator image₂’、I₁’。

And (3) calculating gradient values:

1) according to the relation theta₂-θ₁Determining a temperature gradient d θ/dt;

2) according to the relation m₂-m₁Determining the humidity gradient dm/dt;

3) according to the relation p₂-p₁Determining the gradient dp/dt of the gas flow rate;

4) according to the relation I₂’-I₁' dI '/dt determines the gradient of color numerical ratio dI '/dt.

The method for judging the temperature, the humidity, the gas flow and the image numerical value comprises the following steps:

1) determining whether h is 60, that is, performing data storage once every 60 minutes, counting a +1, h is 1, then repeating the measurement and gradient formation for the same time window in x-1 subsequent periods a, and uploading to the cloud server, and storing time windows in which the gradient of two or more values, i.e., a is 1, a is 2.. a.. x-1, is greater than or equal to 0 for each period a, typically, x is 4, that is, repeating the measurement for 3 hours;

2) in another cycle a ═ x check: whether at least z associated identical stored time windows exist in each preceding period a-1, a-2.. a-x-1, over which two or more gradient values are greater than or equal to 0, i.e. at least 4 completely matching time windows existing within the first three hours of the 4 th hour check;

3) if the time window of the previous period is consistent with the time window of the previous period, the cloud server sends a control signal to the allochroic silicagel heater in the period a which is x, and the allochroic silicagel heater enters an automatic heating mode after receiving the control signal; if the time window does not exist, the automatic heating mode is not started, another period a is counted and compared with x +1, and if the first four hours do not have the completely consistent time window, the 5 th hour is considered to be continued as one period;

the cloud server connection controls the on/off of the allochroic silica gel heater according to the data, for example, if 4 related time windows appear in the time period of 5 minutes to 6 minutes, 6 minutes to 7 minutes, 7 minutes to 8 minutes and 8 minutes to 9 minutes from the previous 3 hours, the allochroic silica gel heater is automatically turned on after 5 minutes of the 4 th hour, and is turned off after 9 minutes.

Preferably, the color-changing silica gel heater also comprises a manual off-line heating mode, when the system is stopped for a period of time, the automatic on-line heating mode is utilized to record the times of automatic heating, the interval minutes between the last starting of the automatic heating distance of each starting and the working time of each starting of the automatic heating, and data signals are transmitted to the central control unit for recording; in an off-line state, whether a manual off-line heating mode is started to heat the allochroic silica gel in the respirator can be determined by judging the date interval between the current date and the last automatic heating start.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.