Introduction to Plasma Introduction to Plasma ProcessingProcessing

SFSF66 Circuit Breaker Circuit Breaker

Student: Hosny, Ahmed A.Student: Hosny, Ahmed A.

Instructor: Prof. Kasra EtemadiInstructor: Prof. Kasra Etemadi

Outline …Outline …

IntroductionIntroduction Why SFWhy SF66 Circuit Breakers? Circuit Breakers? Advantages/DisadvantagesAdvantages/Disadvantages How does it work?How does it work? ApplicationsApplications SummarySummary ReferencesReferences

IntroductionIntroduction

What Kind of What Kind of Plasma do we deal Plasma do we deal with?with?

100 1020 1022 1024108 1010 1012 1014 1016 1018

105

102 104 106

104

103

102

101

100

10-1

Ave

rage

Ele

ctro

n E

nerg

y, [

eV]

Electron Number density, [cm-3]

ThermonuclearPlasmas

Electron Beam

GlowDischarge

ArcDischarge

Solid

MHDGeneratorIonosphere

SolarCorona

InterstellarGas

GaseousNebulae

P=

100

Hz

P=

10 K

Hz

P=

1 M

Hz

P=

100

MH

z

P=

10 G

Hz

P=

1 T

Hz

100 1020 1022 1024108 1010 1012 1014 1016 1018

105

102 104 106

104

103

102

101

100

10-1

Ave

rage

Ele

ctro

n E

nerg

y, [

eV]

Electron Number density, [cm-3]

ThermonuclearPlasmas

Electron Beam

GlowDischarge

ArcDischarge

Solid

MHDGeneratorIonosphere

SolarCorona

InterstellarGas

GaseousNebulae

100 1020 1022 1024108 1010 1012 1014 1016 1018

105

102 104 106

104

103

102

101

100

10-1

Ave

rage

Ele

ctro

n E

nerg

y, [

eV]

Electron Number density, [cm-3]100 1020 1022 1024108 1010 1012 1014 1016 1018

105

102 104 106

104

103

102

101

100

10-1

100 1020 1022 1024108 1010 1012 1014 1016 1018

105

102 104 106

104

103

102

101

100

10-1

Ave

rage

Ele

ctro

n E

nerg

y, [

eV]

Electron Number density, [cm-3]

ThermonuclearPlasmas

Electron Beam

GlowDischarge

ArcDischarge

Solid

MHDGeneratorIonosphere

SolarCorona

InterstellarGas

GaseousNebulae

P=

100

Hz

P=

10 K

Hz

P=

1 M

Hz

P=

100

MH

z

P=

10 G

Hz

P=

1 T

Hz

IntroductionIntroduction

What is Circuit What is Circuit Breakers (CBs)?Breakers (CBs)?

CB is one of the most essential CB is one of the most essential safety mechanisms in electric safety mechanisms in electric

networks.networks. Interrupt short circuit currents Interrupt short circuit currents

(~ 60kA, low pf ~ 0.1).(~ 60kA, low pf ~ 0.1). Fault clearance time is very Fault clearance time is very

important for power system important for power system stability and avoid equipment stability and avoid equipment damage for itself and the rest damage for itself and the rest of the network.of the network.

Introduction (Cont.)Introduction (Cont.)

CBs typesCBs types Oil circuit breakersOil circuit breakers Vacuum circuit Vacuum circuit

breakers breakers Magnetic Air Circuit Magnetic Air Circuit

BreakersBreakers Air-blast circuit Air-blast circuit

breakersbreakers SFSF66 circuit breakers circuit breakers

Figure 2 SF6 partial interrupter unit.

Advantages/Disadvantages?Advantages/Disadvantages?

SFSF66 has a dielectric strength of about two to three has a dielectric strength of about two to three times that of air.times that of air.

It is nontoxic.It is nontoxic. It is nonflammable.It is nonflammable. It is noncorrosive; it doesn’t react with other It is noncorrosive; it doesn’t react with other

materials because it is inert gas. However, when materials because it is inert gas. However, when it is heated to 5000C it decomposes and its it is heated to 5000C it decomposes and its decomposition products react with other decomposition products react with other materials.materials.

It exhibits excellent properties for arc quenching. It exhibits excellent properties for arc quenching. So, it used as an interrupting medium in circuit So, it used as an interrupting medium in circuit breakers instead of air or oil.breakers instead of air or oil.

Applications Applications

Gas-insulated Gas-insulated switchgear (GIS)switchgear (GIS)

Figure 3 GIS layout