主变低压侧区内单相接地保护分析及引起负荷损失的思考.pdfVIP

DOI:10.13882/ki.ncdqh.2024.02.010Safety|安全生产

主变低压侧区内单相接地保护分析及

引起负荷损失的思考

*

朱晓东，冯宗建，王其林，郑润蓝

（中国南方电网深圳供电局有限公司，广东深圳518000）

摘要：

110kV主变10kV低压侧母线桥发生一起区内单相接地，仅有接地变保护动作跳闸变低开关且闭

锁备自投，造成负荷损失。母线桥接地故障一直持续至运行人员手动切除主变高压侧断路器，故障存在

扩大的隐患。文章对故障期间主变差动、主变高低后备保护、接地变和备自投动作行为进行分析，确认

相关保护动作行为的正确性。为避免主变区内故障引起负荷损失，提出备自投采用变低自产零序电流反

闭锁的判据优化方案。为及时切除故障避免故障扩大，提出备自投跳闸变低联跳变高的动作优化，对提

高电源可靠性和设备安全性具有积极参考意义。

关键词：

主变；单相接地；接地变；备自投；差动保护；后备保护中图分类号：

TM727

Analysis

of

Single-phase

Grounding

Protection

in

Low-voltage

Side

of

Main

Transformer

and

Consideration

of

Load

Loss

*

ZHU

Xiaodong,

FENG

Zongjian,

WANG

Qilin,

ZHENG

Runlan

(Shenzhen

Power

Supply

Bureau

of

China

Southern

Power

Grid

Co.,

Ltd.,

Guangdong

Shenzhen

518000,

China)

Abstract:

A

single-phase

grounding

occurred

in

the

area

of

the

bus

bridge

on

the

10

kV

low-voltage

side

of

the

110

kV

main

transformer.

Only

the

grounding

transformer

protection

action

tripped

the

low-voltage

switch

and

locked

the

standby

automatic

switch,

resulting

in

load

loss.

The

bus

bridge

grounding

fault

continued

until

the

operator

manually

cut

off

the

circuit

breaker

at

the

high-voltage

side

of

the

main

transformer,

which

had

the

potential

of

expansion.

This

paper

analyzes

the

differential

protection

of

main

transformer,

high

and

low

backup

protection

of

main

transformer,

grounding

transformer

and

automatic

switching

of

backup

during

fault,

and

confirms

the

correctness

of

relevant

protection

actions.

In