uolmsee lecture 001 power circuit breakers

"Prof Dr. Suhail Aftab Qureshi" 1

POWER CIRCUIT BREAKERSAND

SUBSTATIONS

“Prof Dr. Suhail Aftab Qureshi”

BYBY


Classification of circuit Breaker and isolators,Terminology’ Circuit Breakers, Arcs, SF6 Switchgear & Circuit Breakers, Air Blast Circuit Breakers, oil Circuit Breaker, Special Purpose Circuit Breakers & Isolators, D.C Circuit Breakers,Breakers requirement, Testing, Switchgear Testing, Synthetic Testing, Substation Layout and Design,

Power Circuit Breakers and Substations


BOOKSBOOKS

1.1. "Advances in H.V insulation and Arc "Advances in H.V insulation and Arc interruption'in SFinterruption'in SF66 and Vacuum", and Vacuum",

By V.N. Maller & M.S Naidu.By V.N. Maller & M.S Naidu.

2.2. "Power Circuit Breakers Theory and Design", "Power Circuit Breakers Theory and Design",

By C.H. Flurscheim.By C.H. Flurscheim.

3.3. "ELECTRICAL SUBSTATION", ENGINEERING "ELECTRICAL SUBSTATION", ENGINEERING AND PRACTICE, AND PRACTICE,

BY S RAO.BY S RAO.

Power Circuit Breakers and Substations


1.1. Classification of Circuit Breakers and Classification of Circuit Breakers and IsolatorsIsolators

a.a. IntroductionIntroductionb.b. Circuit Breakers, Switching Isolators, Circuit Breakers, Switching Isolators,

Isolator or DisconnectorsIsolator or Disconnectors

Contents


2. Terminology:

a. Service Voltageb. Recovery Voltagec. Restriking Voltage (TRV)d. Interruption with Restrikese. Prospective Currentf. Prospective Breaking Currentg. Breaking Capacityh. Symmetrical Breaking Capacityi. Asymmetrical Breaking Capacityj. Making Currentk. Arcing Durationl. Make Timem. Operating Duty

Contents


2. Terminology:

n. Load Current Interruption

o. Interruption of Induction Current (Fault

Currents, small, inductive current)

p. Interruption of capacitive Currents

q. Asynchronous switching

r. Auto Reclosure

s. Delayed Current Zero

t. Fault Making

u. Evolving faults.

Contents


3. Circuit Breaker Arcs

a. Plasma and Thermal Ionisation (Substance i.e.solid liquid, Gas, Plasma)

b. Ionisation Due to collision of Electronsc. Deionizationd. Properties of the Arce. Striking the Arcf. External Characteristics of the Arcg. Arc stability.h. Dynamic Arc characteristicsi. The A.C Arcj. General Mathematical Arc Modelk. The Mayr Arc equationl. The Cassie Arc equation

Contents


3. Circuit Breaker Arcs

m. Application of Arc Models.

m1. Pre-zero current (low Arc Resistance)

m2. Post-zero current (High Arc Resistance)

Contents


4. SF6 Switchgear

a. Arc Interruption is SF6

al . Physical & Chemical Properties

a2. Arc Extinction is SF6

a3. Nozzle Design

a4. Arc Extinction Parameters.

a5. Throat Blocking)

Contents


4. SF6 Switchgear

b. SF6 Circuit Breaker

bl. Arc chamber; General

b2. Double pressure Arc chamber

b3. Circuit Breaker Type. (Live Tank & Dead)

c. SF6 switching Isolators & other equipment.

cl. Switching Isolators.

c2. Current Transformers

Contents


5. Air Blast Circuit Breakers.

a. Arc extension

b. Pressurised Head- Atmospheric Head, Air Blast C.B

b1. Constructions.

b11. Auxiliary Chambers.

b12. Tripping/Closing resistors.

b13. Auxiliary Equipment.

Contents


6. Oil Circuit Breaker

a. Generalb. Bulk-Oil circuit Breakers. c. Minimum Oil Circuit Breaker.

7. Special Purpose Circuit Breakers & Isolators.

a. Air Blast Breakers with transverse air Jet b. Water circuit Breakersc. Pantograph Isolator

Contents


8. D.C Circuit Breakers.

a. Producing of current zero (Four different methods)

9. Circuit Breakers requirement.

a. Current Interruption

b. Recovery voltage withstand.

c. Recovery voltages calculation by current Injection Techniques

c1. Current injection sequence.

c2. Examples of current Injection

d. Arc theory in short-line fault calculations

Contents


10. Switchqear Testinq

a. High voltage TYPE TESTS (IEC-56-4)

al. Lightning Impulse Testsa2. Switching Impulse test.a3. Power-Frequency voltage tests

b. Short circuit current TYPE TESTS.b1. Short-time current b2. Breaking currentb3. Transient Restriking b4. Load switchingb5. Earthing Condition b6 Latchingb7. Contact Conditionb8. Critical current

Contents


c. Type tests related to service conditions

c1. Short line fault

c2. Asynchronous switching

c3. Close loop switching

c4. Transformer magnetisting current switching

c5. Capacitance current switching

Contents


d. Miscellaneous TYPE tests.

d1. Mechanical

d2. Climatic Conditions

d3. Geographical Conditions

d4. Thermal

Contents


e. Testing Equipment

e1. Generators and Transformers

e2. Part testing

e2.1 Single phase testing

e2.2 Unit testing

Contents


11. Synthetic Testing

f1. Principles of synthetic testing

f2. Skeats Circuit

f3. Parallel Injection test circuit

f4. Series Injection test circuit

Contents


12. Substation Layout and Design

a. Introduction

b. Basic Requirements

b1. System security

b2. Flexibility of operation

b3. Maintenance Facilities

b4. Protection Facilities

b5. Site-area & location

b6. Cost

Contents



c. Busbar Configuration

c1. Single busbarc2. Duplicate Busbarc3. Duplicate Back to Backc4. Transfer Busbarc5. 1&1/2 Circuit Breaker Arrangementc6. Mesh Arrangementc7. By Pass Facilities.c8. Location of current transformersc9. Indoor or Outdoor substationc10. Segregatione11. Phase-segregated & Insulated phase Busbar.

Contents



d. Substation Earthing.

d1. Earth Resistivity

d2. Design of earth meshes.

Contents

uolmsee lecture 001 power circuit breakers

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