How much is the current flowing in the transmission line?

Click For Summary
SUMMARY

The current flowing in the transmission line from a small power plant producing 6.0 kV and 150 A is calculated using the transformer ratio. The voltage is stepped up to 240 kV before reaching the substation. The relationship I(p)/I(s) = V(s)/V(p) indicates that the primary current I(p) is 150 A, while the secondary current I(s) can be determined using the voltage ratio. The resistance of the transmission line (75 ohms) does not impact the current calculation in this context, as it only affects voltage drop downstream.

PREREQUISITES
  • Understanding of transformer operation and voltage/current relationships
  • Basic knowledge of electrical circuit theory
  • Familiarity with Ohm's Law and its applications
  • Concept of power transmission and line resistance effects
NEXT STEPS
  • Research transformer equations and their applications in power systems
  • Study the effects of line resistance on voltage drop in transmission lines
  • Learn about power factor and its significance in electrical transmission
  • Explore advanced topics in electrical engineering, such as load flow analysis
USEFUL FOR

Electrical engineers, power system analysts, and students studying electrical transmission systems will benefit from this discussion.

golriz
Messages
43
Reaction score
0
Asmall power plant produces a voltage of 6.0kV and a current of 150A. The voltage is stepped up to 240kV by a transformer before being sent to a substation. The resistance of the transmission line between the power plant and the substation is 75 ohm. How much is the current flowing in the transmission line?


I(p)/I(s)= V(s)/V(p) s= stationary P= primary
V= IR


I(p) = 150 , V(p) = 6.0kV , V(s) = 240kV , I(s) = ?
 
Physics news on Phys.org
golriz said:
I(p)/I(s)= V(s)/V(p) s= stationary P= primary

I(p) = 150 , V(p) = 6.0kV , V(s) = 240kV , I(s) = ?

Plug in the numbers and solve. V = IR is not needed here.
 
oh, why?
I don't know why V = IR is not needed here?
 
It occurred to me (after discussing this with somebody else) that I may not understand the layout here.

Perhaps you have a figure you can look at to answer this question: is the 75 ohm line in between the power plant and the transformer, or is it between the transformer and the substation?
 
I think it is between the transformer and the substation.
 
In that case, the 75Ω will affect the voltage at the substation, but not at the transformer. It is irrelevant here.

I'm not sure why they included that information, maybe just to throw you off?
 
Last edited:

Similar threads

Long distance electrical transmission efficiency
  • · Replies 2 ·
Replies
2
Views
2K
Electricity in transmission lines (Simple V^2/R =P)
  • · Replies 12 ·
Replies
12
Views
3K
Transmission cable problem involving power loss
  • · Replies 2 ·
Replies
2
Views
995
Current Flowing through High Voltage AC Transmission Lines
  • · Replies 8 ·
Replies
8
Views
2K
To reduce cost and weight, power transmission lines are made
  • · Replies 6 ·
Replies
6
Views
1K
Power Line Losses: Trivial Problem, Confusing Answer
  • · Replies 9 ·
Replies
9
Views
2K
Power loss in transmission lines
  • · Replies 20 ·
Replies
20
Views
11K
Electric current flowing in a power transmission line
  • · Replies 16 ·
Replies
16
Views
2K
Propagation speed and LC model of transmission line
  • · Replies 21 ·
Replies
21
Views
2K
Input impedance of a "Ladder" transmission line
  • · Replies 3 ·
Replies
3
Views
2K