﻿ 浅析变压器绕组直流电阻不平衡因素及处理对策 Analysis of Unbalanced Factors and Countermeasures for DC Resistance of Transformer Winding

Transmission and Distribution Engineering and Technology
Vol.07 No.02(2018), Article ID:25601,8 pages
10.12677/TDET.2018.72005

Analysis of Unbalanced Factors and Countermeasures for DC Resistance of Transformer Winding

Jianhua Li

Chongqing Nanruiborui Transformer Co. Ltd., Chongqing

Received: Jun. 1st, 2018; accepted: Jun. 20th, 2018; published: Jun. 27th, 2018

ABSTRACT

The unbalance rate of DC resistance in transformer windings is influenced not only by the defects of the production and the resistance value of the component parts themselves, but also by the resistance value of the winding itself and the actual temperature of each winding in the test. In this paper, a transformer with a DC resistivity problem is analyzed, and the test data contrast analysis method is used to determine the factors affecting the unbalanced DC resistance factors, such as phase, length of lead, external area and air velocity, etc., and treatment measures are provided, Ensure the overall quality of the product.

Keywords:Transformer, DC Resistance, Countermeasures

1. 引言

2. 问题描述

3. 测试情况与影响因素分析

3.1. 我国电力变压器直流电阻不平衡率标准

3.2. 问题变压器高压绕组基本情况

3.3. 测试数据及问题处理

3.3.1. 三相绕组测试数据

JYR-40E采用伏安法单片机进行自动控制的变压器直流电阻测试仪，具体接线如图3所示，各分接档位直流电阻测试值如表1

3.3.2. 影响因素分析及措施

Figure 1. Transformer body

Figure 2. Connection group diagram of transformer

Figure 3. Connection diagram of DC resistance test of transformer

Figure 4. Relation diagram between transformer tap and DC resistance of high voltage winding of transformer

Table 1. Test value of DC resistance of high voltage windings in each transformer substation when SFZ11-63000/110 transformer enters oven

Table 2. Statistics of test values of DC resistance of single winding sets

Table 3. Table of each phase resistance test value discrepancies when removing the first wire guide pole and the K pressure connector with the value before the package

3.3.3. 进一步以9档测试结果进行对比分析

4. 结论

Table 4. The difference of test values of each phase resistance of SFZ11-63000/110 transformer products

Table 5. DC resistance values of SFZ11-63000/110 transformer products and finished products tested

Figure 5. The relationship between the tap and the DC resistance of SFZ11-63000/110 transformer inlet and finished products

Table 6. Comparison and analysis of DC resistance values of SFZ11-63000/110 transformer products in 9 gears at different times

1) 根据单个绕组测量的直流电阻值(特别是三相绕组电阻值差异较大时)结合引线结构在满足引线出头位置前提下套装时进行必要相位调整，一般情况下绕组电阻值大的要在引线短的相位(通常BC相可以调整)，因为引线越长电阻越大，可以相互弥补，最终减少直流电阻不平衡率。如该台产品高压绕组三相不平衡率本身就达到1.22%，且C相绕组最大，不进行BC相对换，器身装配后由于引线长度原因会导致直流电阻不平衡率超过2%。

2) 器身进灶烘烤时必须进行电阻值测试，计算不平衡率，对出现异常要进行多方面分析，排除器身制造过程和组部件质量缺陷导致不平衡率偏大，保证产品整体质量。

3) 由于工艺改进及生产进度要求，整体套装烘烤套铁后，1天左右进行进灶试验，三相器身中绕组接触外界面积和空气流速不一样，导致三相绕组实际温度变化不一样，会影响直流电阻测试值偏差，影响判断。在分析时要将温度影响一并考虑，提高问题判断能力。

Analysis of Unbalanced Factors and Countermeasures for DC Resistance of Transformer Winding[J]. 输配电工程与技术, 2018, 07(02): 35-42. https://doi.org/10.12677/TDET.2018.72005

1. 1. 宋文翠, 陈朋, 孙成田, 吕超. 变压器绕组直流电阻异常的分析与处理[J]. 变压器, 2017(5): 66-69.

2. 2. 刘阳. 浅谈变压器直流电阻的试验[J]. 中国新技术新产品, 2017(12): 44-45.

3. 3. 刘海龙, 万亦农, 龚杰, 周科, 赵宪. 一起110 kV变压器直流电阻与变比异常的分析与处理[J]. 变压器, 2017(1): 73-74.

4. 4. 谷国瑞. 变压器直流电阻异常分析和处理[J]. 农村电工, 2017(5): 42-43.