Power lost in transmission lines

In summary, the conversation discusses a power station that produces 1000MW of electrical energy and the loss of 7% in a 500kV transmission line. The question is to determine the line's resistance. The conversation includes the equations P=I2R and P=V2/R, as well as the attempt at solving the problem. However, the correct answer is 17.5 ohms instead of 268 ohms.
  • #1
pat666
709
0

Homework Statement



A typical power station produces 1000MW of electrical energy. Seven percent of the power is lost in a 500kV transmission line. Whats the lines resistance?

Homework Equations



P=I2R

The Attempt at a Solution


Thought this problem was simple but I keep getting it wrong.
P=I2R so P=V2/R
7 percent is lost @ 500Kv
so 0.97*1000*106 = (500*10^3)^2/R
R=268ohms but the actual answer is 17.5 ohms?
Thanks
 
Physics news on Phys.org
  • #2
The V in V^2/R is the voltage drop along the line - which you don't know
Work out the power lost, then the total current, then try
 
  • #3
So P=VI
total I: 1000*10^6/500*10^3=2000A (that can't be right can it, its huge)
0.7*1000*10^6-1000*10^6=9.3*10^9W (power lost)
9.3*10^9=2000^2/R
R=4.3*10^-3ohms- that's too small now?
btw thanks for replying
 

FAQ: Power lost in transmission lines

1. What is power lost in transmission lines?

Power lost in transmission lines refers to the amount of electrical energy that is dissipated or lost as heat during the transmission of electricity from a power plant to consumers. This loss is caused by factors such as resistance in the transmission lines, voltage drops, and electromagnetic interference.

2. Why is power lost in transmission lines?

Power is lost in transmission lines due to the resistance of the materials used to construct the lines, as well as the distance and voltage level of the transmission. As electricity travels through the lines, some of it is converted to heat due to the resistance of the wires, resulting in power loss.

3. How is power lost in transmission lines calculated?

The amount of power lost in transmission lines can be calculated using the formula P = I²R, where P is power loss, I is the current flowing through the lines, and R is the resistance of the lines. This formula takes into account the effects of both current and resistance on power loss.

4. What are the impacts of power lost in transmission lines?

The main impact of power lost in transmission lines is the decrease in efficiency and reliability of the transmission system. This can result in higher energy costs for consumers and potential power outages. Additionally, power loss contributes to environmental pollution as more energy needs to be generated to compensate for the lost power.

5. How can power lost in transmission lines be reduced?

To reduce power loss in transmission lines, various measures can be taken such as using materials with lower resistance, increasing the voltage levels, and minimizing the distance between power plants and consumers. Regular maintenance and upgrades to the transmission system can also help to reduce power loss and improve efficiency.

Similar threads

Long distance electrical transmission efficiency
Replies
2
Views
1K
To reduce cost and weight, power transmission lines are made
Replies
6
Views
1K
Electricity in transmission lines (Simple V^2/R =P)
Replies
12
Views
3K
Power Line Losses: Trivial Problem, Confusing Answer
Replies
9
Views
1K
Optimizing Voltage for Power Transmission Efficiency
Replies
4
Views
4K
Generator from a power plant delivering electric power
Replies
1
Views
2K
How transmission lines deliver (established?) power from generator
Replies
8
Views
2K
Power loss in transmission lines
Replies
20
Views
10K
Why is power loss = I^2R instead of P=VI or P=I^2R?
Replies
14
Views
2K
P = VI = (281V)(3.75A) = 1054 W
Replies
6
Views
7K

Hot Threads

Recent Insights

Back
Top