T45 P&D

Question 1

Why does the 45 operate at 4160V instead of 440V?

Answer 1

More voltage = less current
* Less current means there is less power loss through heat,& less cooling required.

V=I x R

Question 2

Explain Intergrated Electrical Propulsion in a T45

Answer 2

• Has 2 Diesel Gens & 2 GT
• All the prime movers generate electricity that power propulsion & 440v system at the same time(Known as IEP)
• 2 prime movers are running at a time
• It is advantageous as this method is cheaper
• less maintenece required
• less fuel consumption

Question 3

What DG’s does 45 use?

Answer 3

• 2 x 2MW DG’s
• Supplies low speed/low fuel consumption.
• Replaced by GT when more power required

Question 4

T45 transformers

Answer 4

• Step down 4160v to 452v to supply the LV system
• 452v accounts for volatage drop between transformer & switchboard where it becomes 440v

Question 5

HV Harmonic filter

Answer 5

• The IGBT’s (insulated-gate bipolar transistor) in the converter creates distortions on the current
• They can cause damage to machines or interfere with electronics
• The HV harmonic filters out these frequencies

Question 6

Insulated Gate Bipolar Transistors rectifier

Answer 6

• Used in high-power converters to change AC into DC
• It is a switch that turns on & off rapidly

Question 7

T45 GT output

Answer 7

• 4.160Kv
• 3 phase
• 60hz
• 21MW

Question 8

T45 DG output

Answer 8

• 4.160KV
• 60hz
• 3 phase
• 2MW

Question 9

LV harmonic filters

Answer 9

• Equipment on the LV system also create harmonics
• Occur over a wide range of frequencies
• LV filter measures the frequencey & produces current of the same frequencey as the distortion but opposite,cancelling it out

Question 10

What are the effects of harmonics on systems & equipment?

Answer 10

• Decreased efficency
• Heating in cables
• Noise in transformers
• Disturbed electronic equipment (computers,telephones)