Electrical equipment preventive test test @ handover
Switch cabinet cabinet transformer maintenance
The effect of preventive test
Electrical equipment insulation preventive test is an important measure to ensure the safe operation of equipment. The preventive test, can discover hidden inside the electrical equipment insulation defects, and be eliminated by maintenance, serious person must be replaced, so as to avoid the occurrence of equipment insulation breakdown in operation, causing power outages or equipment damage and other irreversible loss.
1 insulation defect classification
The insulation defects of electrical equipment, some is due to manufacturing quality caused by the poor, most are caused by external factors in the operation, such as over voltage, atmospheric conditions (moisture, heat, force, chemical action, and goods). The insulation defects can be divided into two categories. A class is the concentration of defects, such as crack, porcelain insulator motor insulation partial wear, extrusion rupture, another kind is the distribution of defects, refers to the overall decline in insulated electrical equipment, organic material such as motors, transformers, bushings and other equipment in the outer layer of insulation, damp or the overall damp insulation oil damp metamorphism; materials; electrical aging of solid insulation aging deterioration, electrochemical.
Classification of 2 preventive test method
Preventive test of electric equipment and method can be divided into non destructive test and destructive test of two categories, the former refers to the damage to the insulating method at low voltage or other not, detection of various properties of the insulation, the test results analysis, judge the existence of the internal defects of equipment insulation. For example, measure the insulation resistance and leakage current, voltage distribution along the surface of the insulation measurement etc.. Destructive testing refers to the AC voltage withstand test, it can expose the insulation in the presence of dangerous concentration of defects, ensure a certain insulation dielectric strength. However, AC withstand voltage test because the test the applied voltage is high, may lead to injury and a cumulative effect for insulation. For solid insulation, once the insulation breakdown occurring AC voltage withstand test, completely lost electric performance. Therefore, the rules of 35kV and below voltage electrical equipment should be AC voltage withstand test. 110kV and above voltage class equipment, it is necessary to make AC withstand voltage test. AC voltage shall be conducted in the qualified non destructive test after. If the non destructive testing has been detected in insulation defects, you first have to repair, and then do the AC voltage withstand test, so as to avoid unnecessary damage insulation.
Analysis and judgment of 3 preventive test results
"Preventive test code for electric power equipment" preventive test project, for various electrical equipment and standards stipulated period. In actual work, test items should strive for effective, for different performance equipment often need to focus on the different testing methods; test cycle according to the degradation speed, electrical equipment insulation in the operation of the operation experience, workload size and other factors, the test data should be necessary as temperature and humidity correction and conversion, comparison then with the previous test results or the same type of equipment test results, comprehensive analysis and judgment. According to practical experience, the following table lists the preventive test of insulation method can insulation defect detection and its effect.

 

 

试验方法	需测量绝缘介质等值电路中的参数	发现缺陷的可能性					总评
		分布于整个被试品的缺陷	在电极间构成桥路连接的贯穿性缺陷	没有构成的贯穿性缺陷	潮湿与污秽	电气强度的裕度降低
测量绝缘电阻及泄漏电流	R1	当严重受潮，贯穿性电导增长时能发现	按泄漏电流与电压的关系曲线能很好的发现	不易检出	能很好发现	对某些缺陷可以给出间接指示	主要方法之一
吸收关系的分析R60/R15``	R-C	发现受潮很有效，但不能发现游离	能检出，但必须积累经验	能检出，但必须积累经验	能检出，但必须积累经验	不能发现	估计受潮程度
测量介损	R1,R-C C0-C2	由tgδ-t的关系曲线发现受潮，由tgδ-U的关系曲线发现游离	对小电容量的试品能很好地检出	小电容量的试品能发现	能检出	对某些缺陷可以给出间接指示	主要方法之一
局部放电	C0-C2	能很好地发现游离、老化	不能	能检出火花放电和游离的缺陷	能间接判断	能发现	研究运用中
交流耐压试验	s	不能	当电气强度降低时可能发现	当电气强度降低时可能发现	当电气强度降低时可能发现	能发现	与其他配合，检查最低电气强度
电压分布	沿绝缘子元件的电压分布C1,R1	仅适用于绝缘子串和支持绝缘子中	能发现	不能发现	能间接判断	能发现	主要方法之一
气相色谱分析	CO、 CO2、 H2、 CH4、 C2H2、 C2H6、 C2H4	过热可以很好的发现（C2H4、 CO大），老化可以很好发现（CO2大）	产生高温和火花放电时可以发现（C2H4、 C2H2大）	局部放电可以发现（C2H4、 H2大）	沿面放电可以发现（C2H2大）	放电可以很好发现（C2H2大）	主要方法之一
测量直流电阻	三相绕组电阻	线径不一	分接开关不良	焊接不良，螺丝压得不紧			主要方法之一
油质简化分析	绝缘油	能	不能	不能	能很好发现	能发现	主要方法之一

 

 

Can be seen from the table, each kind of test method can only detect the insulation defects, one aspect of the therefore, by a single test method, it is sometimes difficult to judge the insulation is good or bad, must according to the characteristics of various test methods and test results, compared with each other and complement, and strive to make accurate judgments. This requires us in the practical work, to grasp the various test methods, pay attention to improve the ability of comprehensive test analysis.
Safety requirements of electrical test 1
In order to ensure the safety of people and equipment, is vital for high voltage electric test. All high voltage test personnel shall strictly abide by the "electricity safety regulations" and the relevant provisions of the high voltage test, and after may participate in the high-pressure test study, examination qualified rear. Safety requirements for electrical test are:
(1) testing of all electrical equipment shall be field test procedures according to the "preventive test code for electric power equipment" and the unit developed by. In order to ensure the test quality, improve test efficiency, must do a series of preparatory work before the experiment, an important test items to put forward the test scheme and security, organizational measures, with the chief engineer's approval, arrange test personnel to seriously study, fully discussed, completely clear, know the score.
(2) before work should consult the test equipment of previous test reports and defect records, and brought to the site test, to test for analysis check.
(3) and tools needed for testing equipment, meter, wiring, should prepare ahead of time, check the qualified, fully equipped, safe place to test site; site test should choose the suitable position, flat, away from the charged equipment and sidewalks, the high-voltage circuit should not be crossing the sidewalk, stairs; around the test site must be set to the fence, and the suspension "stop, Danger! High Voltage" sign.
(4) the start of the experiment, the test should be responsible for re inspection, verification: testing the wiring is correct, the regulator in the zero position, test indicator gauge in zero position, test equipment on unmanned work, live parts of enough safe distance and some people care.
(5) where the test required ground parts shall be earthed reliably. The grounding wire must be connected to ground fixed, not free to pick up in the barbed wire or tube, the connection must be reliable grounding wire.
(6) high voltage test work shall have at least two people attended, the operation should take a clean line of gloves. The responsible person shall be responsible for field devices and the safety of personnel, personnel must obey the command responsible person. Pressurized by the person in charge of the work orders and obtain the echo relevant staff after the voltage applied to the power supply is closed. The test operators and supervisory personnel in the compression process, should be highly concentrated attention, time monitoring test equipment and instrument indication. Once the abnormal phenomenon, should cut the test power, then the pressure regulating equipment returns null, stop test. To investigate the cause, timely treatment, can switch on the power to a test, not blindly try again.
(7) outdoor tests, such as the case of snow, wind, thunder, rain, the larger the weather, should immediately stop the pressure test work.
(8) the need to replace the test connection end or test, must ensure that the test power with breaking point, significant test equipment to discharge, high pressure part of the test transformer grounding, can.

 

6.2 power transformer of AC test voltage values in table 6.2
                 Table 6.2 the power transformer of AC voltage test

额定 电压 kV	最高 工作 电压kV	线端交流试验电压值kV		中性点交流试验电压值kV
		全部 更换 绕组	部分 更换 绕组	全部 更换 绕组	部分 更换 绕组
6	6.9	25	21	25	21
10	11.5	35	30	35	30
15	17.5	45	38	45	38
20	23.0	55	47	55	47
35	40.5	85	72	85	72
110	126.0	200	170(195)	95	80
220	252	360 395	306 336	85 (230)	72 (170)
500	550	630 680	536 578	85 140	72 120

Note: the values in brackets are applicable to non fixed earthing or small reactance grounding system;

 

The 6.3 arc suppression coil
6.3 pilot projects of arc suppression coil and cycle

序号	试  验  项  目	周  期
1	油中溶解气体色谱分析	交接时、1年、大修后、必要时
2	绕组直流电阻	交接时、3年、大修后、必要时
3	绕组绝缘电阻、吸收比	交接时、3年、大修后、必要时
4	绕组的tgδ	交接时、必要时
5	绝缘油试验	交接时、投运前、3年、大修后、必要时
6	交流耐压试验	交接时、大修后、必要时
7	消弧线圈内电压、电流互感器的绝缘和变比试验	交接时、大修后、必要时

6.4 dry type transformer

 

 

6.4 pilot projects and cycle of dry type transformer

序号	试  验  项  目	周  期
1	绕组直流电阻	交接时、3年、大修后、必要时
2	绕组绝缘电阻、吸收比或极化指数	交接时、3年、大修后、必要时
3	交流耐压试验	交接时、3年、大修后、必要时
4	穿心螺栓、铁轭夹件、绑扎钢带、铁心、线圈压环及屏蔽等的绝缘电阻	交接时、大修时
5	绕组所有分接的电压比	交接时、更换绕组后、必要时
6	校核三相变压器的组别或单相变压器极性	交接时、更换绕组后
7	空载电流和空载损耗	交接时、更换绕组后
8	短路阻抗和负载损耗	交接时、更换绕组后
9	环氧浇注型干式变压器的局部放电测量	交接时、更换绕组后、必要时
10	测温装置及其二次回路试验	交接时、更换绕组后

 

6.5 dry reactor
Dry point reactor test project: the connected system equipment overhaul for AC voltage withstand test (Table 6.1 No. 7)

 

 

The 6.6 grounding transformer and transformer neutral point high resistance device
Test item 6.4 grounding transformer and transformer neutral point high resistance device and cycle

 

  

序号	试  验  项  目	周  期
1	绕组直流电阻	交接时、3年、大修后、必要时
2	绕组绝缘电阻、吸收比	交接时、3年、大修后、必要时
3	绝缘油试验	交接时、投运前、3年、大修后、必要时
4	交流耐压试验	交接时、3年、大修后、必要时
5	穿心螺栓、铁轭夹件、绑扎钢带、铁心、线圈压环及屏蔽等的绝缘电阻	交接时、大修时
6	空载电流和空载损耗	交接时、更换绕组后
7	短路阻抗和负载损耗	交接时、更换绕组后
8	整体密封检查	交接时、大修后

 

6.7 gas insulated transformer

 

 

Test item 6.4 gas insulated transformer and cycle

 

 

 

 

序号	试  验  项  目	周  期
1	SF6气体的湿度（20℃的体积分数）	交接时、3年、大修后、必要时
2	SF6气体泄露试验	交接时、大修后、必要时
3	绕组直流电阻	交接时、3年、大修后、必要时
4	绕组绝缘电阻、吸收比或（和）极化指数	交接时、3年、大修后、必要时
5	交流耐压试验	交接时、3年、大修后、必要时
6	二次回路试验	交接时、大修后、必要时

 

6.8 box type transformer

 

 

Test item 6.4 box type transformer and cycle

序号	试  验  项  目	周  期
1	绕组直流电阻	必要时
2	绕组绝缘电阻、吸收比	必要时
3	绝缘油试验	必要时
4	交流耐压试验	必要时

6.9 special connecting structure of transformer
6.9.1 high voltage bushing through a transformer device connected to the GIS SF6 high voltage wire
A. handover and after overhaul test
According to the provisions of the standard and requirements of the project
B. preventive test
Test the project according to the following content, period of each project and according to the requirements of Table 6.1 executive.
The experimental project:
1) SF6 high voltage wire device of SF6 gas humidity in the detection and leakage test respectively, according to table 8.1 number 1 and number 2;
2) of low voltage winding of the transformer DC resistance, DC leakage, dielectric loss factor and insulation resistance test;
3) transformer core test;
4) transformer high voltage winding and GIS together for insulation resistance test, use 5000V megohmmeter to measure the absorption ratio and polarization index;
5) transformer other projects and GIS test respectively, according to Table 6.1 and table 8.1.
Transformer 6.9.2 high voltage bushing through oil filling full sealing high pressure wire device and a high-pressure oil filled cable connection
A. handover and after overhaul test
According to the provisions of the standard and requirements of the project
B. preventive test
Test the project according to the following content, period of each project and according to the requirements of Table 6.1 executive.
The experimental project:
1) transformer and oil filling full sealing high pressure wire insulating oil chromatographic analysis device per month, not the first half of the 1 insulation analysis of water content in oil; insulating oil test cycle and high pressure oil filled cable according to table 11.3;
2) of low voltage winding of the transformer DC resistance, DC leakage, dielectric loss factor and insulation resistance test;
3) transformer core test;
4) the high voltage winding of the transformer and the high voltage wire joint device and a high-pressure oil filled cable together for insulation resistance test, use 5000V megohmmeter to measure the absorption ratio and polarization index;
5) outer sheath and the outer sheath arrester test of power cable;
6) other projects refer to table 6.1.
Low voltage circuit breaker and automatic arc magnetic switch
Low voltage circuit breaker and test items, automatic demagnetizing switch cycle and the requirements in table 8.3
Table 8.3 low voltage circuit breaker and test items, automatic demagnetizing switch cycle and requirements

序号	项目	周期	要求	说明
1	操作机构合闸接触器和分、合闸电磁铁的	1)交接时                2)操作机构大修后                       3)必要时	1)操作机构分、合闸电磁铁或合闸接触器端子上的最低动作电压应在操作电压额定值的30%~65%之间                    2）在使用电磁机构时，合闸电磁铁线圈通流时的端电压为操作电压额定值的80%（关合电流峰值等于及大于50kV时为85%）时应可靠动作
2	合闸接触器和分、合闸电磁铁线圈的绝缘电阻，辅助回路和控制回路绝缘电阻	1）交接时 2）3年 3）必要时	1）交接时绝缘电阻不应小于10 MΩ 2）直流电阻应符合制造厂规定	采用500V或1000V兆欧表

 

The automatic demagnetizing switch still should be normally open, normally closed contact division switching sequence, the main contact, arc extinguishing contact surface and the action with the situation and the arc gate is complete examination. Type DM to the new switching arc magnetic switch still should check the arc grid plate number.
8.4 vacuum circuit breaker
Test items, vacuum circuit breaker period and the requirements in table 8.4
Requirements of test items, table 13 cycle, vacuum circuit breaker

 对自动灭磁开关尚应作常开、常闭触点分合切换顺序，主触头、灭弧触头表面情况和动作配合情况以及灭弧栅是否完整等检查。对新切换的DM型灭磁开关尚应检查灭弧栅片数。

8.4 真空断路器

真空断路器的试验项目、周期和要求见表8.4

表13  真空断路器的试验项目、周期、要求

 

 

序号

项  目

周 期

要         求

说    明

1

绝缘电阻

1)交接时 2)年 3)大修后 4)必要时

1)整体绝缘电阻参照制造厂规定或自行规定 2)断口和用有机物制成的提升杆的绝缘电阻不应低于下表中的数值：MΩ

试验类别

额定电压kV

3~15

20～40.5

72.5

交接时

1200

3000

6000

大修后

1000

2500

5000

运行中

300

1000

3000

2

交流耐压试验(断路器主回路对地、相间及断口)

1)交接时 2)1～3年 3)大修后 4)必要时

断路器在分、合闸状态下分别进行，试验电压值按DL/T593规定值

1)更换或干燥后的绝缘提升杆必须进行耐压试验，耐压设备不能满足时可分段进行 2)相间、相对地及断口的耐压值相同

额定电压(kV)

交接试验电压(kV)

7.2

32

12

42（中性点有效接地系统28）

40.5

95

3

辅助回路和控制回路交流耐压试验

1)交接时 2)6年 3)大修后 4)必要时

试验电压为2kV

可用2500V兆欧表代替

4

导电回路电阻

1)1～3年 2)6年 3)大修后

1)大修后应符合制造厂规定 2)运行中不宜大于出厂值的1.2倍

用直流压降法测量，电流不小于100A

5

断路器的合闸时间和分闸时间，分、合闸的同期性，触头开距，合闸时的弹跳过程

1)交接时 2)机构大修后  3)必要时

1）分、合闸时间，分、合闸同期性和触头开距应符合制造厂规定 2）合闸时触头的弹跳时间不应大于2ms

在额定操作电压下进行

6

操动机构合闸接触器和分、合闸电磁铁的最低动作电压

1)交接时 2)大修后 3)必要时

1)操动机构分、合闸电磁铁或合闸接触器端子上的最低动作电压应在操作电压额定值的30%～65%间 2）在使用电磁机构时，合闸电磁铁线圈通流时的端电压为操作电压额定值的80%(关合峰值电流等于或大于50kA时为85%)时应可靠动作

7

合闸接触器和分、合闸电磁铁线圈的绝缘电阻和直流电阻

1)交接时   2)大修后 3）必要时

1)绝缘电阻不应小于10MΩ   2)直流电阻应符合制造厂规定

采用1000V兆欧表

8

真空灭弧室真空度的测量

1）交接时 2)不超过3年 3）必要时

与历次试验结果和同类型设备试验结果相比无明显差别

可以用断口耐压代替

9

检查动触头上的软联结夹片有无松动

1)交接时 2)大修后 3)必要时

应无松动

 High voltage switch cabinet
Test project, high voltage switch cabinet period and the requirements in table 8.9
Test items, table 18 high voltage switch cabinet period and requirements

 

 

 

 

 

 高压开关柜

高压开关柜的试验项目、周期和要求见表8.9

表18  高压开关柜的试验项目、周期和要求

 

 

序号	项    目	周    期	要            求	说    明
1	辅助回路和控制回路绝缘电阻	1)交接时 2)6年 3)大修后	绝缘电阻不应低于2MΩ	采用1000V兆欧表
2	辅助回路和控制回路交流耐压试验	1)交接时 2)大修后 3)必要时	试验电压为2kV	用2500V兆欧表代替
3	断路器、隔离开关及隔离插头的导电回路电阻	1)交接时 2)必要时	1)大修后应符合制造厂规定 2)运行中应不大于制造厂规定值的1.5倍	隔离开关和隔离插头回路电阻的测量在有条件时进行
4	操动机构合闸接触器和分、合闸电磁铁的最低动作电压	1)交接时 2)大、小修后 3)机构大修后 4)必要时	1)操作机构分、合闸电磁铁或合闸接触器端子上的最低动作电压应在操作电压额定值的30%~60%之间 2)在使用电磁机构时,合闸电磁铁线圈通流时的端电压额定值的80%(关合峰值电流等于或大于50kA时为85%)时应可靠动作
5	合闸接触器和分合闸电磁铁线圈的绝缘电阻和直流电阻	1)交接时 2)大修后 3)必要时	1)交接时绝缘电阻应大于2MΩ 2)直流电阻应符合制造厂规定	采用1000V兆欧表
6	绝缘电阻试验	1)交接时 2)大修后 3)必要时	应符合制造厂规定	在交流耐压试验前、后分别进行
7	交流耐压试验	1)交接时 2)大修后 3)必要时	试验电压值按DL/T593规定	1)试验电压施加方式：合闸时各相对地及相间；分闸时各相断口 2)相间、相对地及断口的试验电压值相同
8	检查电压抽取(带电显示)装置	1)交接时 2)大修后 3)必要时	应符合制造厂规定
9	SF6气体泄漏试验	1)交接时 2)大修后 3)必要时	应符合制造厂规定
10	压力表及密度继电器校验	1)交接时 2)6年 3)必要时	应符合制造厂规定
11	五防性能检查	1)交接时 2)大修后 3)必要时	应符合制造厂规定

 

All kinds of test items of 8.8.2 and other forms of high voltage switch cabinet:
Other types, such as measuring cabinet, test items and capacitor voltage transformer cabinet cabinet \ cycle and requirements may refer to the table about number 8.9. The main components in the cabinet (such as transformer \ \ capacitor arrester) test items according to the provisions of relevant sections of this standard.
8.9 nickel cadmium battery direct current screen
Nickel cadmium battery DC panel (cabinet) of the test items, cycle and the requirements in table 8.10.
Table 19 nickel cadmium battery DC panel (cabinet) of the test items, the period and requirements

8.8.2 其它形式高压开关柜的各类试验项目:

其它型式,如计量柜,电压互感器柜和电容器柜等的试验项目\周期和要求可参照表8.9中有关序号进行.柜内主要元件(如互感器\电容器\避雷器等)的试验项目按本标准有关章节规定。

8.9  镉镍蓄电池直流屏

镉镍蓄电池直流屏（柜）的试验项目、周期和要求见表8.10。

表19  镉镍蓄电池直流屏(柜)的试验项目、周期和要求

序号	项    目	周期	要            求	说    明
1	镉镍蓄电池组容量测试	1)1年 2)必要时	按DL/T459规定
2	蓄电池放电终止电压测试	1)交接时 2）1年 3)必要时
3	各项保护检查	1）交接时 2）1年	各项功能均应正常	检查项目有：   a)闪光系统   b)绝缘监察系统   c)电压监视系统   d)光字牌   e)声响
4	镉镍屏(柜)中控制母线和动力母线的绝缘电阻	1）交接时 2）必要时	绝缘电阻不应低于10MΩ	采用1000V兆欧表。有两组电池时轮流测量