Guide for the Frequency Domain

Spectroscopy Measurement for

transformer bushing CSG:Deng Jun

Contents

1 Frequency Domain Spectroscopy

2 Research Basis

3 Applications

4 Purpose of the Guide

5 Scope of the Guide

6 Working Group

7 Management and Schedule

1、Frequency Domain Spectroscopy

tanδ=Iloss/Icharge='r'/'r =C''/C'.

Bushing

Polarisation processes

The equivalent circuit

1、Frequency Domain Spectroscopy

Effect of thermal, electrical, and

chemical factors, and water

Separate impacts of oil

conductivity and moisture

2、Research Basis

IDAX 300 DIRANA

Broadband Dielectric Spectrometers

Oil-impregnagted insulation paper

2、Research Foundation

10-3

10-2

10-1

100

101

102

103

10-3

10-2

10-1

100

101

102

tan

f/Hz

0.7%

1.0%

1.6%

2.8%

3.3%

10-3

10-2

10-1

100

101

102

103

10-2

10-1

100

tanδ

f/Hz

0天 7天 18天 27天

Effect of moisture content Effect of aging

1 2

3

4 5

2、Research Foundation

DP versus Aging Time tanδ versus freuency

Insulation moisture content

2(0.5%) 2(5%) 2(0.5%)

1

5i

i

Temperature

Water Content in Oil Water Content in paper

10ppm 30ppm （0.5%） （5%）

20°C ε1=2.13 ε1=2.13 ε2=4.58 ε2=5.17

80°C ε1=2.06 ε1=2.06 ε2=4.66 ε2=5.45

Permittivity 1

2

3

4

5

6

Water diffusion

direction

Water Content 0.5%

5%Conductive rod

2、Research Foundation

9

Insulation moisture content and effect of temprature

Electric field distribution at 20℃ Electric field distribution at 80℃

the outer field strength decreased by 5.6%, the inner field strength increased by 8.1%.

the outer field strength decreased 1.3% from 80 ℃ to 20 ℃, inner field strength

increased 1.8%

2、Research Foundation

10

Test Results of FDS——26kV Bushing

2、Research Foundation

11

2、Research Foundation

Test Results of FDS——40.5kV Bushing

12

2、Research Foundation

Test Results of FDS——72.5kV Bushing

13

2、Research Foundation

Test Results of FDS——72.5kV Bushing

14

2、Research Foundation

Test Results of FDS——72.5kV Bushing

3、Applications

Water Content 2.7%

Water Content 4.4%

FDS

Conductive rod rusty Case 1

3、Applications

FDS

Water Content 4.8%

①（7.29%）

④ （1.78%）

③（2.50%）

②（7.42%）

⑥（6.7%）

⑤（3.84%）

⑦ （1.36%）

⑧ （1.16%） ⑨ （3.21%）

⑩（5.27%）

Water Content Distribution

Seal failure

Case 2

3、Applications

Water Content 2.1% X-wax of the insulation paper

PD

Case 3

FDS

3、Applications

Case 4

Technical Informationof ABB

4、Purpose of Guide

The purpose of this guide is to present FDS measurements for

transformer bushings

Insulation

aging

X-wax

produced

by PD

Insulation

moisture

There is a draft “ Use Guide for Dielectric Frequency Response

Test ”applied to the transformers. And it has been proved that

dielectric frequency response test is a validity method to

determine the moisture content in transformer’s solid insulation.

But the bushings is not in the scope of the above draft for

PC57.161

5、Scope of Guide

This guide applies to the dielectric loss frequency domain spectroscopy (FDS)

measurement for transformer bushings. It establishes the method to measure the

dielectric response at different frequencies and to detect the insulation defects of

bushings. The guide includes the following topics:

Safety precautions;

Requirements for measuring instrument;

Measurement methods for the frequency domain spectroscopy of bushings;

Data analysis and assessment;

Maintenance Suggestion

Annex (typical examples about the relation between dielectric loss frequency

domain spectroscopy and insulation defects).

6、Working Group

Approximate number of entities expected to be actively involved in the

development of this project: 7

(1) China Southern Power Grid;

(2) State Grid Corporation of China;

(3) Tsinghua University;

(4) Southwest Jiaotong University;

(5) ABB;

(6) Siemens;

(7) Alstom.

7、Management and Schedule

Some measures have been taken to ensure that the project can be completed:

Face to face technical exchange with IEEE Transformer Committee each year in

the United States;

Form close connection with the IEEE Inc. Beijing Representation Office;

Invite IEEE P1870 Chairman（Yao Xiao） to guide the implementation of this

project;

7、Management and Schedule

June 2018

PAR approved

Jan. 2019

Draft V1

Jan. 2020

Draft V3

July 2018

1st meeting

Aug. 2019

Draft V2

June 2020

Final draft

Aug. 2020

Sponsor ballot

Dec. 2020

Submit Revcom