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Topic
|
Power Transformer
|
Distribution Transformer
|
Rating
|
Above 200MVA
|
Around 10KVA-500KVA
|
Flux density
|
Much higher
|
lower
|
Voltage level
|
400KV,230KV,110KV,66KV,33KV
|
11KV,6.6KV,3.3KV,400V,230V
|
Used for
|
Transmission purpose at heavy load
|
used for the distribution of electrical energy at low voltage
|
Efficiency Level
|
Approximately 98-99%
|
Around 50-70%
|
Used in
|
Power plant, transmission line, transmission substation
|
Local areas
|
Insulation Level
|
High
|
Lower than power Transformer
|
Core loss
|
Higher
|
lower
|
Copper loss
|
Relatively lower as not at the end of consumer
|
higher
|
Winding connection
|
Primary-star
Secondary-delta
|
Primary-delta
Secondary-star
|
Load
|
Fully loaded
|
Not fully loaded
|
Cooling system
|
ONAN,OFAF,ONWF,OFWF
|
Usually ONAN
|
Tap changer
|
On -load
|
Off-load
|
Protection
|
Buchholz relay,
Explosion vent pressure relief,
Temperature indicator
Oil gauge level
Lightening arrestor
|
HRC fuse
Over current relay
Buchholz relay
|
Need for voltage regulation
|
No need
|
Important factor
|
