阅读说明：本技术 基于fwo法的干式绝缘设备活化能获取方法 (Method for acquiring activation energy of dry-type insulating equipment based on FWO method ) 是由 张鑫 张心洁 段明辉 姚创 *** 马昊 王伟 张弛 马小光 王洋 于 2019-12-09 设计创作，主要内容包括：本发明公开了一种基于FWO法的干式绝缘设备活化能获取方法,可以在热失重试验基础上,对干式绝缘设备绝缘材料活化能进行定量计算。该方法是一种多升温速率法,通过利用一组环氧树脂试样测得的TG和DTG曲线图谱,计算绝缘材料活化能。另外,结合FWO法的优势在于：1.可以完整测取同一样品整个热老化进程中的活化能变化量,试验简便,检测效率高；2.避免了样本之间差异性对计算结果的影响,计算结果更加准确。(The invention discloses a method for acquiring activation energy of dry-type insulation equipment based on a FWO method, which can quantitatively calculate the activation energy of an insulation material of the dry-type insulation equipment on the basis of a thermal weight loss test. The method is a multi-heating-rate method, and the activation energy of the insulating material is calculated by utilizing TG and DTG curve maps measured by a group of epoxy resin samples. In addition, the advantages of combining the FWO method are: 1. the activation energy variation of the same sample in the whole thermal aging process can be completely measured, the test is simple and convenient, and the detection efficiency is high; 2. the influence of the difference between the samples on the calculation result is avoided, and the calculation result is more accurate.)

1. A method for acquiring activation energy of dry-type insulation equipment based on an FWO method is characterized by comprising the following steps:

according to the definition of Arrhenius about the activation energy of the substance, a kinetic equation which is commonly used by a heterogeneous system under the non-constant temperature condition is given, and the formula is shown as (1):

β＝dT/dt (2)

wherein k represents the chemical reaction rate, A is a constant coefficient related to the chemical reaction rate being evaluated, R is the universal gas constant, T is the temperature, α is the chemical reaction conversion, E_aFor the activation energy of the chemical reaction, f (α) is a function of the reaction mechanism and β is the rate of temperature increase.

By integrating equation (1), the product can be obtained

Wherein T is₀The temperature at which the reaction starts is considered as the temperature T at which the reaction starts₀At a low, negligible reaction rate, the above equation can be written as

Order to

By

Thus, the formula (4) can be converted into

Where E/R is constant, the problem of solving the temperature integral becomes a look-up function

doyle approximation is used herein

p_D(u)＝0.00484e^-1.0516u

Simultaneous equations (7) and (8) can be derived:

the activation energy E in equation (9) can be obtained by the following two methods:

(1) t due to peak temperatures of various thermal spectra at different β_pWhere the α values are approximately equal, and thus are between 0 and α_pValue within the range

(2) since the same α is selected at different β, then

Technical Field

The invention relates to the technical field of transformer operation and test, in particular to a method for acquiring activation energy of dry-type insulation equipment based on an FWO method.

Background

Dry insulation is the most common solid insulation method in power systems, and generally, dry insulation equipment refers to equipment which is cast and cured with epoxy resin to form a main insulation layer, and common dry insulation equipment includes dry transformers, dry voltage transformers, dry air reactors and the like.

The dry-type insulation equipment is generally considered to have stable insulation performance and less insulation defects, but in recent years, the defects and the failure rate of the dry-type insulation equipment are high and exceed those of oil-immersed insulation equipment. In order to solve this problem, it is necessary to perform insulation performance detection of dry type insulation equipment. However, due to the solid insulation property, the detection method of the dry insulation property is few, and the effect in practical application is poor. In order to solve the problems, some researchers have provided a dry-type insulation performance detection method based on activation energy quantitative characterization from the viewpoint of the intrinsic chemical characteristics of the insulation material. In this method, dry insulation activation energy measurement is a key of the problem.

The FWO method is called a flynn-wall-ozawa method, is an integral dynamic method, and is generally used for solving chemical reaction kinetic parameters under the condition of no chemical reaction mechanism function. The aging characteristic of the dry-type insulating material under the thermoelectric combination scene is combined, the FWO method is introduced into the field of chemical reaction activation energy calculation of dry-type insulating equipment, the dry-type insulating equipment activation energy acquisition method based on the FWO method is provided, and a foundation is laid for the aging state evaluation of the dry-type insulating equipment.

Disclosure of Invention

In order to meet the requirement of the dry insulation activation energy measurement in the prior art, the invention aims to provide a dry insulation equipment activation energy acquisition method based on an FWO method.

To achieve the object of the present invention, the present invention provides a dry type insulation apparatus activation energy obtaining method based on FWO method,

according to the definition of Arrhenius about the activation energy of the substance, a kinetic equation which is commonly used by a heterogeneous system under the non-constant temperature condition is given, and the formula is shown as (1):

β＝dT/dt (2)

wherein k represents the chemical reaction rate, A is a constant coefficient related to the chemical reaction rate being evaluated, R is the universal gas constant, T is the temperature, α is the chemical reaction conversion, E_aFor the activation energy of the chemical reaction, f (α) is a function of the reaction mechanism and β is the rate of temperature increase.

By integrating equation (1), the product can be obtained

Wherein T is₀The temperature at which the reaction starts is considered as the temperature T at which the reaction starts₀At a low, negligible reaction rate, the above equation can be written as

Order to

By

To know

Thus, the formula (4) can be converted into

Where E/R is constant, the problem of solving the temperature integral becomes a look-up function

In the light of the above-mentioned problems,

doyle approximation is used herein

p_D(u)＝0.00484e^-1.0516u

Simultaneous equations (7) and (8) can be derived:

the activation energy E in equation (9) can be obtained by the following two methods:

(1) t due to peak temperatures of various thermal spectra at different β_pWhere the α values are approximately equal, and thus are between 0 and α_pValue within the range

Are all equal, therefore lg β is equal to

Linear relationship with a slope of

The slope can be used to obtain the value E;

(2) since the same α is selected at different β, then

Is a constant value, thus 1g β and

linear relationship with a slope of

The E value can be found from the slope.

Compared with the prior art, the invention has the advantages that,

by using the method for acquiring the activation energy of the dry-type insulation equipment based on the FWO method, the activation energy of the insulation material of the dry-type insulation equipment can be quantitatively calculated on the basis of a thermal weight loss test. The method is a multi-heating-rate method, and the activation energy of the insulating material is calculated by utilizing TG and DTG curve maps measured by a group of epoxy resin samples.

In addition, the advantages of combining the FWO method are:

1. the activation energy variation of the same sample in the whole thermal aging process can be completely measured, the test is simple and convenient, and the detection efficiency is high;

2. the influence of the difference between the samples on the calculation result is avoided, and the calculation result is more accurate.

Detailed Description

The present invention will be described in further detail with reference to specific examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

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