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工频耐压试验装置

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产品名称: 工频耐压试验装置
产品型号: GZ/TDM
产品展商: 华电美伦
会员价格: 0.00 元
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简单介绍

工频耐压试验装置是根据DL/T848.2-2004行业标准而设计生产的。GZ全套工频耐压试验装置由YDJ(TDM、GYC、YDQ)系列高压试验变压器和MLXC/MLTC控制箱(台)组成,其中控制箱(台)由调压器、测量、控制及保护等部分组成的一体化装置。适用于电力系统、工矿企业、科研部门等对各种高压电气设备、电器元件、绝缘材料进行工频高压下的绝缘强度试验


工频耐压试验装置  的详细介绍

工频耐压试验装置是根据DL/T848.2-2004行业标准而设计生产的。GZ全套工频耐压试验装置由YDJTDMGYCYDQ)系列工频耐压试验变压器和MLXC/MLTC控制箱(台)组成,其中控制箱(台)由调压器、测量、控制及保护等部分组成的一体化装置。适用于电力系统、工矿企业、科研部门等对各种高压电气设备、电器元件、绝缘材料进行工频高压下的绝缘强度试验。   

 

1.1 产品分类

产品分为一体式装置和分体式装置两类。

 

1.2 产品型号

产品型号:

GZ   X --- XXX / XXX

                                   装置额定输出电压(kV

                                   装置额定容量(kVA

                                   分体式(F)、一体化(Y

                                   工频高压试验装置

 

 

一、           产品结构

工频耐压试验装置采用单框芯式铁芯结构。初级绕组饶在铁芯上,高压绕组在外,这种同轴布置减少了漏磁通,因而增大了绕组间的耦合。产品的外壳制成与器芯配合较佳的八角形结构,整体外形显得美观大方。其外部结构图见图1,内部结构图见图2

 

 

 

 

 

 

 

 

 

 

 

 

 

 


1:单台试验变压器                   2:单台试验变压器内部结构图

外部结构示意图

1—短路杆D      2—均压球        3—高压套管        4—变压器提手

5—油阀    67—次压输入ax    89—测量端子EF   10—变压器外壳接地端       

11—高压尾X        12—高压输出A    13—高压硅堆       14—变压器油       

15—铁芯     16—次低压绕组         17—测量绕组       18—二次高压绕组

在试验变压器中,ax为低压输入端子,EF为仪表测量端子,AX为高压输出。

 

二、           工作原理

GZ系列工频高压耐压试验装置由高压试验变压器和控制箱(台)组成,其中控制箱(台)是集调压器、测量、控制、保护及信号等部分组成的一体化装置。

高压试验变压器采用单框芯式铁芯,初级绕组绕在铁芯上,测量绕组和高压绕组采用绝缘筒绕制并套在初级绕组外,系同轴布置结构。通过调节控制箱(台)内的调压器输出电压,接入高压试验变压器的初级绕组,根据电磁感应原理,可获得需要的高压电压。

1、  GZ系列工频耐压试验装置的工作原理图见图3

 

 

 

 

 

 

 

 

 

 

 


3.工频耐压试验装置工作原理图

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


                                   

 

 

 

 

 

 

 

 


4:三台试验变压器串级接线原理图

图中:P—容量(kVA)      V—电压(kV)      G1G2—绝缘支架

 

2、三台工频耐压试验变压器串级获得更高电压的接线原理见图5。串级高压试验变压器有很大的优越性,因为整个试验装置由几台单台试验变压器组成,单台试验变压器容量小、电压低、重量轻,便于运输和安装。它既然可串接成高出几倍的单台试验变压器输出电压组合使用,又可分开成几套单台试验变压器单独使用。整套装置投资小,经济实惠。图5中,在第一级和第二级的每个单元试验变压器中都有一个励磁绕组A1C1A2C2。在三台串级试验变压器基本原理中,低压电源加在试验变压器Ⅰ的初级绕组a1x1上,单台试验变压器Ⅰ、Ⅱ、Ⅲ的输出电压都是V。励磁绕组A1C1给第二级试验变压器Ⅱ的初级绕组供电;第二级试验变压器Ⅱ的励磁绕组A2C2给第三级试验变压器Ⅲ的初级绕组供电。第二级试验变压器Ⅱ和第三级试验变压器Ⅲ的箱体分别处在对地为1V2V的高电位上,所以箱体对地是绝缘的,试验变压器Ⅰ的箱体是接地的。这样第一级、第二级、第三级试验变压器对地的额定输出电压分别为1V2V3V;其额定容量分别为3P2P1P

 

 

 

 

 

 

三、           使用方法

1、  试验变压器做被试品的工频耐压试验使用接线原理图见图6

 

 

 

 

 

 

 

 

 

 

 

 


5:被试品工频耐压试验装置接线图

图中:R1—限流电阻       FRC—阻容分压器     RF—球间隙保护电阻

                G—球间隙          CX—被试品

注:高压尾必须可靠接地

工频耐压试验装置中限流电阻R1应根据试验变压器的额定容量来选择。如高压侧额定输出电流在100~300mA时,可取0.5~1Ω/V(试验电压);高压侧额定输出电流为1A以上时,可取1Ω/V(试验电压)。常用水电阻作为限流电阻,管子长度可按150kV/m考虑,管子粗细应具有足够的热容量(水阻液配制方法:用蒸馏水加入适量硫酸铜配制成各种不同的阻值)

球间隙及保护电阻:当电压超过球间隙整定值时(一般取试验电压的110%~120%),球间隙放电,对被试品起到保护作用。球间隙保护电阻可按1Ω/V(试验电压)选取。

在工频耐压试验中,低电压侧测量电压(仪表电压)不是非常准确的,其原因是由于试验变压器存在着漏抗,在这个漏抗上必然存在着压降或容升,使试品上的电压低于或高于低压侧测量电压表上反映出来的电压。工频耐压试验时,被试品上的电压高于试验变压器的输出电压,也就是所谓容升现象。感应耐压试验时,试验变压器的漏抗必然存在着压降。为了准确测量被试品上所施加的电压,因此常在高压侧接入FRC阻容分压器来测量电压(见图6)

工频耐压试验操作注意事项

(1)     试验人员应做好分工,明确相互间联系方法。并有专门人监护现场安全及观察试品状态。

(2)     被试品应先清扫干净,并绝对干燥,以免损坏被试品和试验带来的误差。

(3)    对于大型试验,一般都应先进行空升试验。即不接试品时升压至试验电压,校对各种表计,调整球间隙。

(4)    升压速度不能太快,并必须防止突然加压。例如调压器不在零位时突然合闸。也不能突然切断电源,一般应在调压器降至零位时拉闸。

(5)    当电压升至试验电压时,开始计时,到1min后,迅速降压到1/3试验电压以下时,才能拉开电源。

(6)    在升压或耐压试验过程中,如发现下列不正常情况时,应立即降压,切断电源。停止试验并查明原因:①电压表指针摆动很大;②发现绝缘烧焦或冒烟;③被试品内有不正常的声音。

(7)    耐压试验前后应测量绝缘电阻,检查绝缘情况。

2、  试验变压器在做被试品的直流耐压或泄露试验时接线原理图如图7

注:此试验应先抽出短路杆“D”,图7中所示。

 

 

 

 

 

 

 

 

 

 

 

 


6:高压直流泄露试验接线图

图中:VD—高压硅堆     R1—限流电阻      C1—高压滤波电容

FRC—阻容分压器     CX—被试品    μA—带保护微安表

泄露试验中限流电阻R1选择在额定输出电压时,输出端短路电流不超过高压硅堆的蕞大整流。如电压硅堆的蕞大整流电流为100mA时用于60kV的试验装置中,限流电阻按R1=60/0.1=600kΩ选择。限流电阻还应具有足够的容量和沿面放电距离。

高压滤波电容C1一般选择在0.01~0.1μF,当被试品的电容量很大时,C1可省略不用。

泄露试验的操作及注意事项

(1)   试验前应先检查被试品是否停电,接地放电,一切对外连线是否擦干净。要严防将试

验电压加到有人工作的部位上去。

(2)   接好试验装置的接线后,应复查无误后才可加压。应特别注意检查高压设备及引线与地、与操作人员的安全距离,被试品的外壳是否可靠接地,要按安全规程中所规定的内容进行试验。

(3)   对于大电容量设备应缓慢升压,防止被试品的充电电流烧坏微安表。必要时应分级加压,分别读取各级电压下微安表的稳定读数。

(4)   试验过程中,应密切监视被试品、试验装置、微安表,一旦发生击穿、闪烁等异常现象应立即降压,切断电源,并查明原因,详细记录。

(5)   试验完毕,降压,切断电源后应将被试品及试验装置本身充分放电。

 

五、注意事项

1、  按照您所进行的试验接好工作线路。试验变压器的外壳以及操作系统的外壳必须可靠接地。试验变压器高压绕组的X(高压尾)以及测量绕组的F端必须可靠接地。

2、  做串级试验时,第二级、第三级试验变压器的低压绕组的X端,测量绕组的F端以及高压绕组的X(高压尾)均接本级试验变压器的外壳。第二级、第三级试验变压器的外壳必须通过绝缘支架接地。

3、  接通电源前,操作系统的调压器必须调到零位后方可接通电源,合闸,开始升压。

4、  从零开始均匀旋转调压器手轮升压。升压方法有:快速升压法,即20s逐级升压法;慢速升压法,即60s逐级升压法;极慢速升压法供选用。电压从零开始按一定的升压方式和速度上升到您所需的额定试验电压的75%后,在以每秒2%额定试验电压的速度升到您所需的额定电压,并密切注意测量仪表的指示以及被试品的情况。升压过程中或试验过程中如发现测量仪表的指示及被试品情况异常,应立即降压,切断电源,查明情况。

5、  试验完毕后,应在数秒内匀速的将调压器返回至零位,然后切断电源。

6、 本产品不得超过额定参数使用。除试验必须外,决不允许全电压通电或断电。

7、  使用本产品做高压试验时,出熟悉本说明书外,还必须严格执行国家有关标准和操作规程。可参照GB311-83《高压输变设备的绝缘配合,高压试验技术》;《电气设备预防性试验规程》等。

 

六、试验变压器的容量选择

标称试验变压器容量Pn的确定公式:Pn=kVn 2ωCt×10-9

式中:Pn——标称试验变压器容量(kVA)

     Vn——试验变压器的额定输出高压的有效值(kV)

k ——安全系数。k1,标称电压Vn1MV时,k=2;标称电压较低时,k值可取高一些。

Ct——被试品的电容量(pF)

ω——角频率,ω=2πf f——试验电源的频率

被试设备的电容量Ct可由交流电桥测出。Ct的变化很大,可由设备的类型而定。典型数据如下:

简单的棒式或悬式绝缘子             几十微法

简单的分级套管                     100~1000pF

电压互感器                         200 ~ 500pF

电力变压器 1000kVA                 ~1000pF

            1000kVA             1000~10000pF

高压电力电缆和油浸纸绝缘           250~300pF/m

气体绝缘                           ~60pF/m

封闭变电站,SF6气体绝缘           100~10000pF

对于不同的试验电压Vn,选择不同的(适当的)安全系数k。以下列出不同的Vn所选用的k值供参考。

Vn =50~100kV        k = 4

Vn =150~300kV       k = 3

Vn 300kV          k = 2

 

七、控制箱(台)使用说明

本系列控制箱(台)是根据高压试验变压器独特的使用范围而设计生产的,其功能有:

A、    合闸声光报警;

B、     计时声光报警;

C、     电子式低压电流保护(箱式);

D、    高压电压直读;

E、     耐压试验时间自由设定(数显);

F、      移动式结构(台式)

 

7.1  工作原理:

工频耐压试验装置控制箱(台)是由接触式调压器(50kVA以上为电动柱式调压器)及其控制、保护、测量、信号电路组成。它是通过接入220V380V工频电源,调节调压器(即试验变压器的输入电压),以获得所需要的试验高压电压值。其工作原理见图1

 

 

 

 

 

 

 

 

 

 

 


1:控制箱(台)工作原理

 

 


 7.2 结构(面板布置):

 

 

 

 

 

 

 


 

 

 


2:控制箱面板布置

1—电源插座               2—数显时间继电器

3—电子电流整定器         4—启动、停止、计时按钮

5—高压电压指示表         6—低压电流指示表

7—信号灯、报警闪光灯     8—接线柱

 

 

 

 

 

 

 

 

 

 

 

 

 


3:控制台面板布置

1—信号灯、报警闪光灯     2—报警器出音孔

3—电流保护继电器         4—高压电压指示表

5—数显时间继电器         6—启动、停止、计时按钮

7—低压电流表

 

7.3 技术参数、规格及选用配套

工频耐压试验装置控制箱(台)的容量是与调压器是与调压器的容量而标称,如果和试验变压器(短时30min以内工作制)配套工作,可根据中华人民共和国电力行业标准“DL474.4-92”之规定:P0=0.75P选配。式中P0—试验变压器容量;P—调压器容量。如用于电器专业工厂产品作批量试验,调压器容量应等于试验变压器容量,即:P0=P

控制箱(台)的型号及技术参数如表1, 配套高压试验变压器技术参数电话咨询

 

容量(kVA

   

   

外型尺寸(mm

参考重量(kg

相数

电压(V

率(Hz

电压(V

电流(A

MLXC-3

3

1

220

50

240

13.6

17

MLXC-5

5

1

220

50

240

22.7

20

MLTC-10

10

1

220

50

240

45.5

40

MLTC-15

15

1

220

380

50

240

430

68

39

50

MLTC-20

20

2

380

50

430

52.6

55

MLTC-30

30

2

380

50

430

78.9

79

MLTC-50

50

2

380

50

430

131.5

可选

 

 100KVA/200KVA/300KVA/500KVA试验变压器控制台需电话咨询预订

2YDJ系列油浸式高压试验变压器

  

容量

(KVA)

高压电压

KV

高压电流

mA)

低压输入

变比

(/)

温升℃

(30分钟)

电压(V)

电流(A)

YDJ-1.5/50

1.5

50

30

200

7.5

500

10

YDJ-3/50

3

50

60

200

15

500

10

YDJ-5/50

5

50

100

200

25

500

10

YDJ-10/50

10

50

200

200

50

500

10

YDJ-20/50

20

50

400

380

53

500

10

YDJ-30/50

30

50

600

380

79

500

10

YDJ-50/50

50

50

1000

380

12

500

10

YDJ-5/100

5

100

50

200

25

1000

10

YDJ-10/100

10

100

100

200

50

1000

10

YDJ-20/100

20

100

200

380

53

1000

10

YDJ-30/100

30

100

300

380

79

1000

10

YDJ-50/100

50

100

500

380

132

1000

10

YDJ-20/150

20

150

133

380

53

1000

10

YDJ-30/150

30

150

200

380

80

1000

10

YDJ-50/150

50

150

333

380

132

1000

10

YDJ-100/150

100

150

667

380

263

1000

10

YDJ-50/200

50

200

250

380

132

1000

10

YDJ-100/200

100

200

500

380

263

1000

10

YDJ-150/200

150

200

750

380

395

1000

10

YDJ-200/200

200

200

1000

380

526

1000

10

YDJ-300/200

300

200

1500

380

790

1000

10

YDJ-50/300

50

300

170

380

132

1000

10

YDJ-100/300

100

300

333

380

263

1000

10

YDJ-150/300

150

300

500

380

395

1000

10

YDJ-200/300

200

300

667

380

526

1000

10

YDJ-300/300

300

300

3000

380

790

1000

10

 

 

 

 

3TDM系列轻型油浸工频耐压试验装置试验变压器

 

容量

高压电压(KV

高压电流(mA

低压输入

变比

温升

(KVA)

AC

DC

AC

DC

电压

(V

电流

A

/

30

分钟

TDM-1.5/50

1.5

50

70

30

15

200

7.5

500

10

TDM-3/50

3

50

70

60

15

200

15

500

10

TDM-5/50

5

50

70

100

15

200

25

500

10

TDM-10/50

10

50

70

200

50

200

50

500

10

TDM-20/50

20

50

70

400

100

380

53

500

10

TDM-30/50

30

50

70

600

100

380

79

500

10

TDM-40/50

40

50

70

800

105

380

105

500

10

TDM-50/50

50

50

70

1000

100

380

132

500

10

TDM-10/100

10

100

140

100

50

200

50

1000

10

TDM-20/100

20

100

140

200

100

380

53

1000

10

TDM-30/100

30

100

140

300

100

380

79

1000

10

TDM-40/100

40

100

140

400

100

380

105

1000

10

TDM-50/100

50

100

140

500

100

380

132

1000

10

TDM-20/150

20

150

210

133

100

380

53

1000

10

TDM-30/150

30

150

210

200

100

380

79

1000

10

TDM-40/150

40

150

210

267

100

380

105

1000

10

TDM-50/150

50

150

210

333

100

380

132

1000

10

TDM-100/150

100

150

210

667

150

380

263

1000

10

注:本系列产品中有200V的串级抽头,可二台或三台串级成交流100KV150KV200KV300KV直流140KV210KV280KV420KV的高电压。并可根据用户需要在高压绕组中抽出5 15KV的中压抽头,供高压电机作交流耐压试验。并可定制特殊规格的试验变压器。

 

 

7.4操作指南

在操作之前应根据不同被试品的容量、电压等级,先计算好蕞大工作电流,并调整电流保护器。其试验接线应参考本说明书中图1或试验变压器中相关的连接示意图,接地端应良好接地(以下视耐压试验为例)。

7.4.1连接电源(箱式为插座式电源,台式为接线柱式电源),并将调压器手柄旋至零位处,零位开关闭合,零位指示灯(黄灯)亮,(也称调压器零位输出状态指示);

7.4.2按下启动按钮(绿色),接触器吸合,调压器受电,同时工作指示灯(红灯)亮,并发出警报声(警报声随调压器离开零位后,报警声光才能停止);

7.4.3顺时针缓慢均匀地旋转调压器手柄,并密切注视仪表读数,当升到所需高压电压值时,应停止旋转手炳,并及时按下计时按钮(黄色),此时,数显时间继电器顺计时显示时间(计时单位为“s”,秒),当到达设定的时间,控制箱(台)内发出声光报警,及时将调压器手柄反方向旋转,直至调压器回零为止,解除计时按钮,;

7.4.4在升压或耐压试验过程中,如出现短路、闪络、击穿等过电流时,电流继电器保护跳闸,调压器自动断电,表示被试品不合格,此时应将调压器回零,切断电源,检查被试品。

7.5        使用与维护

7.5.1开箱验收时,应检查主控回路接线是否松动,调压器电刷是否接触良好;

7.5.2长期不用时,使用前应用500V兆欧表测量绝缘电阻,其阻值不低于0.5MΩ;

7.5.3电源电压应符合箱(台)铭牌上的输入电压值;

7.5.4本箱(台)设有过电流保护,出厂已调整为额定电流的80%。用于小负载时,应根据被试品的额定容量电流重新设定;

7.5.5使用完毕后,应关好箱(台)门盖,以保持箱(台)内部清洁。
工频耐试验装置,工频试验装置,工频耐压装置,工频交流耐压试验,交流耐压试验装置交直流耐压试验装置测试配件箱,工频高压试验装置价格和工频耐压试验装置属于同一种交流耐压设备。

The industrial frequency withstand pressure test device is designed according to the industry standard of DL/t848.2-2004. GZ full power frequency withstand voltage test apparatus by YDJ (TDM, GYC, YDQ) series of power frequency withstand voltage test transformer and MLXC/MLTC control box (Taiwan), the control box (Taiwan) by the voltage regulator, measure, control and protection device such as a part of integration. It is suitable for testing the insulation strength of various high voltage electrical equipment, electrical components and insulation materials in power system, industrial and mining enterprises and research departments.




1.1 product classification


The products are divided into one-piece and split-type devices.




1.2 product model


Product model:


GZ X -- XXX/XXX


Installation rated output voltage (kV)


Device rated capacity (kVA)


Formula (F), integration (Y)


High frequency high voltage test device






I. product structure


The single-frame core structure is adopted for the test equipment of the industrial frequency. The primary winding is in the core and the high voltage windings are out. This coaxial arrangement reduces the leakage flux and thus increases the coupling between the windings. The shell of the product is made with the perfect octagonal structure with the core, the overall shape looks beautiful and generous. Its external structure is shown in figure 1, and the internal structure diagram is shown in figure 2.































FIG. 1: single test transformer FIG. 2: single test transformer internal structure diagram


Schematic diagram of external structure


1 - short-circuit rod D 2 - all pressure ball 3 - high pressure casing 4 - transformer handle


5 - oil valve 6, 7 - time pressure input a, x 8, 9 - measuring terminal E, F 10 - transformer shell grounding terminal


11 - high-pressure tail X 12 - high - voltage output A 13 - high - pressure silicon stack 14 - transformer oil


15 - iron core 16 - secondary low - voltage winding 17 - measuring winding 18 - secondary high - voltage winding


In the test transformer, a and x are the low-voltage input terminals, E and F are the instrument measuring terminals, a and x are high voltage outputs.




Ii. Working principle


GZ series high voltage power frequency withstand voltage test apparatus is composed of high voltage test of transformer and control box (Taiwan), the control box (Taiwan) is a collection of voltage regulator, measurement, control, protection and signal components such as the integration of device.


The high voltage test transformer adopts single-frame core core, the primary winding is wound around the core, the measuring winding and the high voltage winding are made of insulated barrel and set in the primary windings, and the coaxial arrangement structure. By adjusting the voltage of the voltage regulator in the control box (table), the primary winding of the high voltage test transformer is connected, and the high voltage voltage can be obtained according to the principle of electromagnetic induction.


1. The working principle of GZ series is shown in figure 3

























Figure 3. Working principle diagram of the test device of the working frequency




































































FIG. 4: schematic diagram of cascade wiring of three test transformer


Figure: P - volume (kVA) V - voltage (kV) G1, G2 - insulation bracket




2. The wiring principle of the voltage resistance test transformer cascade is shown in figure 5. Cascade high voltage testing transformer has a lot of advantages, because the entire test apparatus is composed of several single test transformers, small single test transformer capacity, low voltage, light weight, easy to transport and install. Since it can be connected to several times of single test transformer output voltage combination, it can be separately used by several single test transformers. The whole set of equipment investment is small, economical. In figure 5, each unit test transformer at the first and second levels has an excitation winding A1, C1 and A2, C2. In the basic principle of three cascade test transformer, low voltage power supply in test transformer primary winding a1x1 Ⅰ, single transformer test Ⅰ, Ⅱ, Ⅲ output voltage is V. Second-level test A1, C1 to excitation winding transformer Ⅱ the primary winding of the power supply; Secondary test transformer Ⅱ exciting winding A2, C2 to the third level of Ⅲ test transformer primary winding of the power supply. Second-level test transformer Ⅱ and third level test transformer Ⅲ chamber respectively in the ground for v 1 and 2 v high potential, so the box body is insulated to ground, testing transformer Ⅰ box body is grounded. The rated output voltage of the test transformer at the first, second and third levels is 1V, 2V and 3V respectively. The rated capacity is 3P, 2P and 1P respectively.














3. Use method


1. The wiring schematic diagram of the test for the test transformer is shown in figure 6.



























Fig.5: wiring diagram of the test device for the frequency of the test


Figure: R1 - current-limiting resistance FRC - resistance capacitors RF - ball clearance resistance


G - ball clearance CX - tested


Note: high pressure tail must be reliably grounded


The limited current resistance R1 in the test device of the industrial frequency should be selected according to the rated capacity of the test transformer. Such as high side output current rating in 100 ~ 100 ma, preferable 0.5 ~ 1 Ω/V (test voltage); High side, above the rated output current for 1 a desirable 1 Ω/V (test voltage). Water resistance is commonly used as a current limiting resistor, the pipe length can be according to the 150 kv/m, the pipe thickness should have enough heat capacity (water resistance liquid preparation methods: with distilled water adding suitable amount of copper sulfate made into a variety of different resistance).


Ball clearance and protection resistance: when the voltage exceeds the clearance value of the ball clearance (usually 110%~120% of the test voltage), the gap discharge of the ball will protect the subject. Ball gap resistance can press 1 Ω/V (test voltage).


In power frequency withstand voltage test, the low voltage side measure the voltage (instrument voltage) is not very accurate, the reason is because the testing transformer leakage reactance, the leakage KangShang inevitably there is a pressure drop or rise, to try the voltage is lower than or higher than the low voltage side on the measurement of voltage on the voltmeter. The voltage in the test is higher than the output voltage of the test transformer, which is known as the rising phenomenon. The leakage resistance of the test transformer must have a pressure drop when the induction pressure test. In order to accurately measure the voltage applied on the subject, the FRC resistance capacitance voltage divider is often used to measure the voltage (see figure 6).


The operating frequency withstand test operation precautions


(1) the test personnel should do a good job of division of labor and make clear contact methods. There are special people to monitor the safety of the site and observe the test status.


(2) the samples should be cleaned first and thoroughly dry, so as not to damage the errors caused by the test and test.


(3) for large trials, an advanced aerial lift test is generally required. When the test is not taken, the test voltage will be pushed up to the test voltage, and check the various meters to adjust the clearance of the ball.


(4) the lifting speed cannot be too fast, and it must prevent sudden pressure. For example, the regulator does not suddenly switch when it is zero. Also can not cut off the power suddenly, normally should be in the voltage regulator drops to zero place to pull the brake.


(5) when the voltage rises to the test voltage, start the time, and after 1min, the power can be pulled off when the voltage is reduced to a third of the test voltage.


(6) in the process of pressure or pressure testing, if the following abnormal conditions are found, the pressure should be reduced immediately to cut off the power supply. Stop the test and find out the cause: the needle of the voltmeter wiggles a lot; To find that the insulation is charred or smoke; There is an abnormal sound in the test.


(7) the insulation resistance shall be measured before and after the withstand test and the insulation shall be checked.


2. The wiring schematic diagram of test transformer is shown in FIG. 7 in the test of dc withstand voltage or leakage test of the tested product.


Note: this test should first draw out the short circuit rod "D", as shown in figure 7.



























Figure 6: wiring diagram of high voltage dc leakage test


In the figure: VD - high pressure silicon reactor R1 - current-limiting resistance C1 - high - voltage filter capacitance


FRC - resistance capacitance divider CX - tested mu A - band protection microammeter


In the leakage test, the current-limiting resistance R1 selects the maximum rectifier of the high voltage silicon pile at the time of the rated output voltage. As the biggest rectifying silicon stack voltage current is 100 ma used in 60 kv test apparatus, press R1 = 60/0.1 = 600 k resistor Ω choice. The current-limiting resistance should also have sufficient capacity and distance along the surface discharge.


The high voltage filter capacitor C1 is usually selected at 0.01~ 0.1mu F, and C1 can be omitted when the battery capacity is very large.


Leakage test operation and precautions


(1) before the test, check whether the test product is without power, ground discharge, and whether all external connections are cleaned. Be sure to try


The test voltage is added to the site where someone is working.


(2) after the connection of the test device, the pressure should be checked after checking correctly. Special attention should be paid to check the safety distance of the high-voltage equipment and the lead and the ground, and the safety of the operator. The shell of the tested product is reliable and grounded, and the test should be carried out according to the contents stipulated in the safety regulations.


(3) for large capacitance equipment, the device should be slowly pushed up to prevent the charging current of the tested product from burning the microammeter. When necessary, the pressure should be graded, and the stable reading of the microammeter at all levels is read.


(4) during the trial, should be closely monitored by test, test device, microamps table, in the event of breakdown, flashing, such as abnormal phenomenon should immediately step-down, cut off power supply, and find out the reason, the detailed record.


(5) after the test, the pressure will be lowered, and the test equipment and the test equipment should be fully discharged after cutting off the power supply.




V. precautions


1. Connect the working lines according to your experiments. The casing of the test transformer and the operating system must be grounded reliably. The X end (high pressure tail) of the transformer high voltage winding and the F end of the measuring winding must be reliably grounded.


2, do cascade test, the second and third level of testing transformer low voltage winding of X, F of the measuring winding end and high voltage winding of the X client (high end) are the testing transformer shell at the corresponding level. The shell of the second and third stage test transformer must be grounded through an insulated stand.


3. Before switching on the power supply, the operating system's voltage regulator must be transferred to the zero position before switching on the power, closing, and starting pressure.


4. Start from scratch with the hand wheel of the regulator. The method of lifting pressure is: rapid pressure boost method, namely, 20. Slow lift method, i.e. Extremely slow lift pressure for selection. Voltage from scratch in a certain way of booster and speed up to the test voltage rating of the you need, after a 75% rise in the speed of 2% per second test voltage rating to your required voltage rating, and pay close attention to the instructions of measuring instrument and the situation of the subjects to taste. If the indication of the measuring instrument and the abnormal conditions of the test are found in the process of lifting pressure, it should be reduced immediately, cut off the power supply, and find out the situation.


5. After completion of the test, the voltage regulator shall return to zero at a constant speed in a few seconds and then cut off the power supply.


6. This product shall not exceed the rated parameters. Do not allow full voltage power or power failure except for test.


7. When using this product for high voltage test, it is necessary to strictly implement the relevant national standards and operating procedures. The technology of high voltage test can be used in reference to gb311-83. Electrical equipment preventive test procedure, etc.




6. Test transformer capacity selection


Calibration formula for the capacity Pn of test transformer: Pn=kVn 2 omega Ct x 10-9


In formula: Pn -- nominal test transformer capacity (kVA)


Vn -- effective value of the rated output voltage of test transformer (kV)


K -- the safety factor. K is greater than or equal to 1, and the nominal voltage Vn is equal to 1MV, and k= 2. When nominal voltage is low, k value is preferable.


Ct - the electrical capacity of the subjects (pF)


Omega -- the angular frequency, omega equals 2 PI f, f -- the frequency of the test power


The capacitance Ct of the tested equipment can be measured by ac bridge. Ct changes are large and can be determined by the type of device. Typical data is as follows:


Simple rod or suspension insulator dozens of micromethods


Simple grading casing 100~1000pF


Voltage transformer 200 ~ 500pF


Power transformer < 1000kVA ~1000pF


> 1000 kva, 1000 ~ 10000 pf


High voltage power cables and oil-impregnated paper insulated 250~300pF/m


Gas insulation ~60pF/m


Enclosed substation, SF6 gas insulation 100~10000pF


For different test voltage Vn, select different (appropriate

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