Download 02a_Basis stator ground fault protection.pdf PDF

Title02a_Basis stator ground fault protection.pdf
TagsElectrical Engineering Transformer Electrical Components Electric Power Transmission Capacitor
File Size4.2 MB
Total Pages19
Document Text Contents
Page 1

The year of Profitable Growth

Global network of innovation

Basis of Stator-Ground-
Fault Protection

Page 2

Power Automation 2

Power Transmission and Distribution

Power Automation
Progress. It‘s that simple.

Presenter: Dr. Hans-Joachim Herrmann
PTD PA13
Phone +49 911 433 8266
E-Mail: [email protected]

Generator Protection
Basis of Stator-Ground-Fault

Protection

Page 9

Power Automation 9

Power Transmission and Distribution

Power Automation
Progress. It‘s that simple.

Generators Connected via an Unit Transformer
to the Grid

? generator is galvanic isolated

? under the assumption of an ideal transformer, the displacement
voltage caused by an ground fault, can only be measured at the generator

GGG

Page 10

Power Automation 10

Power Transmission and Distribution

Power Automation
Progress. It‘s that simple.

Unit Connection: Elimination of the Disturbance during a
Ground Fault on the High Voltage

Grounding
transformer

üTR =

CLCG CTr

CK

VEO ?
VN
3

(Limb transformation ratio)

VGen
3

100
3

500
3

VV

? ?
R

RPrim
ü

3

2
TR

?
VR

Problem: grid ground faults cause disturbances
due to the coupling capacitance
between the two transformer windings

Solution: attenuation by means of
a load resistor

Note:
At solidly grounded
transformer the VE0 is

appr. 80% of VN/?3

(Safety margin, if solidly
grounding is open)

Page 18

Power Automation 18

Power Transmission and Distribution

Power Automation
Progress. It‘s that simple.

Directional Stator Ground Fault Protection
Directional Characteristic

Page 19

Power Automation 19

Power Transmission and Distribution

Power Automation
Progress. It‘s that simple.

Directional Stator Ground Fault Protection - Logic

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