Interview and Presentation for

National Grid PhD Studentship

2016

Deep Shah

Date : 20/09/2016

OUTLINE

1

ACADEMIC BACKGROUND

MASTER’s THESIS

2

Education and qualifications

• 2015 – 2016 : Master’s degree in Sustainable

Electrical Power from Brunel University.

• Dissertation: “Investigation into generator out-of-step

protection under transient stability phenomena”.

• 2007 – 2011 : Bachler degree in Electrical Engineering

from Kathmandu Engineering College with 76.68%.

• Project: “Wireless monitoring and protection of

transformer.

ACADEMIC BACKGROUND

3

Publications

• 2014 : A Course in Electric Circuit theory book,

Shree Chandeswori Publication Pvt. Ltd Publisher,

Kathmandu, Nepal.

• Also planning to publish master’s dissertation topic in

IEEE Paper.

ACADEMIC BACKGROUND

“Investigation into generator out-of-step protection under transient stability

phenomena”

Academic Supervisor: Prof. Gareth Taylor

Industrial Supervisor: Mr. Jose Ribecca

MASTER’s THESIS

College of Engineering, Design and Physical

Sciences

Brunel University London

4

CONTENT

Introduction

Aim

Procedure

Results and analysis

Conclusion

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INTRODUCTION

Background

• Electrical system exposed to number of

disturbances, that varies on magnitude and

characteristics.

• These disturbances can produces alternations to

operating points of different electrical equipment's.

• Thus, results to undesired relay operation.

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Transient Stable Condition

• The rotor will accelerate.

• δ will increase beyond

recovery.

• Out-of-step condition.

Consequences

• Variation of voltage and currents.

• Severe damage to generator.

• Unwanted operation of distance relays.

AIM

To design and implementation a generator out-of-

step protection relay model for the purpose of

transient stability studies.

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8

PROCEDURE

• Design a generator out-of-step protection relay model in

DIgSILENT PowerFactory with the help of SEL 300G

generator relay manual.

• Design a test system based on IEEE relay testing system.

• Calculating relay out-of-step settings.

• Implementing Modelled relay in test system.

• Carried out transient stability investigation.

• Finally, providing the complete relay step-up guide for out-

of-step protection in generator.

PROCEDURE: MODELLED OUT-OF-STEP RELAY

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Double blinder logic extracted from SEL 300G manual

Designed out-

of-step relay in

DIgSILENT

PowerFactory.

PROCEDURE: TEST SYSTEM

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Initial out-of-step setting calculated value

Use of initial out-of-step setting calculated value in Modelled relay

RESULTS AND ANALYSIS

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Stable

• Short circuit event was defined at

0.3s in bus-3.

• Fault was cleared at 0.680s.

• For 0.380s fault was in the system.

• Yet, system restored the stability.

• As can be seen in output

waveforms.

• So, modeled relay did not send

tripping signal.

RESULTS AND ANALYSIS

12

Unstable

• Short circuit event was defined at

0.3s in bus-3.

• Fault was cleared at 0.690s.

• For 0.390s fault was in the system.

• System becomes unstable.

• As can be seen in output

waveforms.

• Thus, relay gives tripping signal as

an output .

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RESULTS AND ANALYSIS

Some simulation cases

• No tripping in stable condition.

• Tripping signal in unstable

condition.

• No tripping signal in stable

condition.

• Maximum rate of slip.

• Corrected by comparing

setting value with maximum

rate of slip.

CONCLUSION

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The main achievement of this dissertation are:

• The first detailed report on modelling of out-of-step relay

based on SEL 300G generator relay in DIgSILENT

PowerFactory.

• It provides the complete relay step-up guide for out-of-step

protection.

• It also provides to eliminate undesired relay operation for

out-of-step protection.

Thanks for your attention