11_imam_bushing monitoring cawang env
TRANSCRIPT
Online Bushing Monitoring of 500/150 kV IBT on Cawang EHV Substation
Mr. Imam Makhfud & Mr. Eprido Meiladi Transmission System Departement PT. PLN (Persero) P3B Java Bali
Omicron Conference - Bali, October 30, 2013
Contents • Condenser Bushing • Online bushing monitoring • Analysis • Conclusions and Discussion
Condenser Bushing
Source : Paul Gill, Electrical Power Equipment Maintenance and testing
C1 : main insulation C2 : tap insulation C3 : overall insulation
Online Bushing Monitoring
Online Bushing Monitoring
Source : Dynamic Ratings
Imbalance Current
Initial condition, imbalance current is close to zero
Dielectric Current
Source : R.E James, Condition Assessment of High Voltage Insulation
Dielectric Losses is influenced by : 1. Capacitance ( C ) 2. Dielectric dissipation factor (tan δ)
Imbalance Current
1. Zero imbalance current 2. Non zero Imbalance current because of DDF (tan δ) changing 3. Non zero imbalance current because of capacitance changing
Source : Dynamic Ratings
Calculating DDF and Capacitance
Source : Dynamic Ratings
Based on the formula, dielectric dissipation factor and capacitace can be calculated
Analysis
Leakage Current of HV Bushing
Leakage current of HV Bushing phase R is the highest. It is about 36 mA
Imbalance Current of HV Bushing Set
The imbalance current is 0.17%. Warning level is 3%.
Capacitance of HV Bushing
Capacitance of phase R is the highest. It is about 411 pF
DDF of HV Bushing Set
Dielectric dissipation factor of phase R is the highest. It is about 0.76%
Leakage Current of LV Bushing Set
Leakage current of LV Bushing phase T is the highest. It is about 10.5 mA
Imbalance Current of LV Bushing Set
The imbalance current is 0.07%. Warning level is 3%.
Capacitance of LV Bushing Set
Capacitance of phase T is the highest. It is about 404 pF
DDF of LV Bushing Set
Dielectric dissipation factor of phase T is the highest. It is about 0.38%
Conclusions and Discussion • HV Bushing set and LV bushing set of IBT #1 on Cawang
Substation are good condition • Dielectric losses of phase R HV bushing is the highest. For HV
bushing set, the highest probability of breakdown is phase R • Dielectric losses of phase T LV bushing is the highest. For LV
bushing, the highest probability of breakdown is phase T
Load
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Ampere load hv (R)
load hv (S)
load hv (T)
Ambient Temperature
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Amb Temperature
Degree of Dielectric Current
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Dielectric Current
phase S
phase T
Capacitance
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pF
Capacitance
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Dielectric Dissipation Factor
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Dielectric Dissipation Factor
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phase S
phase T
Imbalance Current
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Imb Current
Dielectric Current
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mA
Dielectric Current
Imbalance Current
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Imb Current