controlled switching circuit breaker considerations · 2014. 1. 14. · alstom t&d...

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CIGRE WG A3.07

CONTROLLED SWITCHING

CIRCUIT BREAKER CONSIDERATIONS

Victor F. HermosilloALSTOM T&D

Seminar/Workshop on Controlled SwitchingCIGRE WG A3.07

IEEE/PES Switchgear Committee MeetingSt. Pete Beach, Florida

May 2003

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CIGRE WG A3.07

Circuit Breaker Considerations

� Circuit breaker characteristics� Interrupter wear� Life extension, maintenance intervals� Circuit breaker performance� Benefits for switched equipment� Benefits for the power system & equipment� Conclusions

OUTLINE

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CIGRE WG A3.07

Circuit Breaker Characteristics

Independent-Pole Operated

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CIGRE WG A3.07

Independent-Pole Operated

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CIGRE WG A3.07

Mechanically-Staggered Linkage

Circuit Breaker Characteristics

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CIGRE WG A3.07

Mechanically-Staggered Linkage

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CIGRE WG A3.07

Spring Mechanism

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CIGRE WG A3.07

Hydraulic Mechanism

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CIGRE WG A3.07

� Effect of idle time� Influence of ambient temperature on operating time� Hydraulic pressure - Spring constant

-1

0

1

2

3

0.1 1 10 100 1000

idle time (hrs)

clos

ing

time

varia

tion

(ms)

HydraulicMechanism

SpringMechanism

Timing Characteristics

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CIGRE WG A3.07

0 30 60 90 120 150 180 210 240 270 300 330 3600,0

0,2

0,4

0,6

0,8

1,0

T Target Target Pointnominal instant of contact touch

Volta

ge a

cros

s cir

cuit-b

rake

r (ab

solut

e va

lue) [

pu]

�t making

k + k0 �

k - k0 �

Controlled Closing - RDDS

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CIGRE WG A3.07

Live-Tank Circuit Breaker

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CIGRE WG A3.07

Field Simulation

15 mm and 4.0 msfrom contact touch

02040

6080

100120140

160180200

0.000 0.004 0.008 0.012 0.016

0

5

10

15

20

25

30

35

40

0 5 10 15 20 25 30 35 40

d (mm)

E (k

V/m

m)

Controlled Closing - RDDS

Emax

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CIGRE WG A3.07

Benefits for the Circuit Breaker

� Extension of circuit breaker life,

� Increase in time intervals between interruptermaintenance or retrofit,

� Added value associated with circuit breakerperformance enhancement during currentinterruption in the thermal or in the dielectricregion.

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CIGRE WG A3.07

Interrupter Wear

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CIGRE WG A3.07

Interrupter Wear

Benefits of controlled switching for the purposesof life extension, reduction of maintenance cost:

� Decrease in magnitude of energization currents.

� Reduce associated interrupter wear.

� Lower probability of occurrence of damagingrestrikes.

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CIGRE WG A3.07

Interrupter Wear

� Arcing contact wear

– Source is burning arc across the gap.

– Loss of material caused by vaporization, melting andburnoff.

– Consequences are contact shape distortion andincrease in surface roughness.

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CIGRE WG A3.07

Electrical Wear of an Interrupter

� Depends on:– contact material composition

and micro-structure– contact surface porosity– initial contact shape– manufacturing process– arc current duration,

amplitude, shape� Implications

– erosion, burnoff, vaporization– change in shape, surface

Arcing Contact Wear

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CIGRE WG A3.07

� Depends on:– nozzle geometry– material (teflon) and fillers

� Implications:– increase in diameter of throat– flake-off, erosion, vaporization of

inside surface– changes to the dynamic gas flow

during interruption– degradation of breaker

performance (thermal region)

Teflon Nozzle Ablation

Electrical Wear of an Interrupter

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CIGRE WG A3.07

Interrupter Wear

� Definition of maintenanceinterval

� Number of allowableoperations betweenmaintenance/refurbishment

� Simple relation between theinterrupted current and amaximum number ofoperations

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CIGRE WG A3.07

Improved Assessment of Interrupter Wear

� Separate limits forarcing contact wearand nozzle ablation

� Specific to interrupterdesign

� Can be implementedtogether withelectronic monitoring

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CIGRE WG A3.07

Maintenance Intervals and Costs

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CIGRE WG A3.07

Circuit Breaker Performance Enhancement

� Improve performance during interruption– Thermal region of interruption– Dielectric region of interruption

� Increase or decrease arcing time– Life extension– Unusual system voltages (25 Hz rail system)– Higher X/R ratios– Further reduce restrike probability for severe TRV

applications

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CIGRE WG A3.07

Thermal (Energy Balance) Region

• Rate of Rise of Recovery Voltage (RRRV)• Initial Transient Recovery Voltage (ITRV)• Reignition if current re-established <1/4 cycle

successful interruption failure (reignition)

ETRVETRV


ifault

vTRV

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CIGRE WG A3.07


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CIGRE WG A3.07

Dielectric Region

• Peak value of the transient recovery voltage• Restrike if current re-established >1/4 cycle

successful interruption failure (restrike)

ETRV ETRV


ifault

vTRV

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CIGRE WG A3.07


Contact CoordinationVoltage Gradients on Interrupter Components

E1E3

E5

E4E2

E6

stationary side -0.5 pu

moving side +0.5 pu

Contact coordination HGF1014/63 kA

02468

101214161820

0 20 40 60 80 100 120 140

gap (mm)

E (%

/mm

)

E1

E2

E3

E4

E5

E6

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CIGRE WG A3.07


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CIGRE WG A3.07

Benefits for Power System and Equipment

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CIGRE WG A3.07

� Technical and economic benefits– reduction of stresses on switched equipment leading to

life extension,– control of local transients in the substation,– local surge supression, reducing possible coupling to

the control and protection scheme,– decrease in the severity of remote transients and their

effects on sensitive loads.


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CIGRE WG A3.07


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CIGRE WG A3.07

� Suceptibility– Compromise of system of equipment function– Frequency dependent

� Mechanism– Coupling

• conductive, inductive, radiative– Modes

• common mode, differential mode


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CIGRE WG A3.07

� Conclusions– Effective means of reducing switching transients and

their effects on a power system and equipment• life extension• reduction of maintenance costs• system reliability• power quality

– Enhancement of circuit breaker performance– Alternative to tradition means of transient control

Benefits of Controlled Switching

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CIGRE WG A3.07

� Conclusions– Assessment depends on conditions:

• new or existing installation• planned or unplanned effects

– Driver may be:• desire to acquire experience• problem solving• preventive or corrective

– Can be used in combination with other means oftransient control

Benefits of Controlled Switching

controlled switching circuit breaker considerations · 2014. 1. 14. · alstom t&d...

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