A power outage (also called a power cut, a power out, a power blackout, a power failure, a power loss, or a blackout) is the loss of the electrical power network supply to an end user.There are many causes of power failures in an electricity network. Examples of these causes include faults at power stations, damage to electric transmission lines, substations or other parts of the distribution system, a short circuit, cascading failure, fuse or circuit breaker operation.
Power failures are particularly critical at sites where the environment and public safety are at risk. Institutions such as hospitals, sewage treatment plants, and mines will usually have backup power sources such as standby generators, which will automatically start up when electrical power is lost. Other critical systems, such as telecommunication, are also required to have emergency power. The battery room of a telephone exchange usually has arrays of lead–acid batteries for backup and also a socket for connecting a generator during extended periods of outage.
You are testing a new car in a wind-tunnel for road and wind resistance. At a speed of 75.0 Km/hr you have found that 63.0 % of the total output power of an automobile engine is used in overcoming the resistance of the road and wind against the movement of the car. If the output power of a...
Firstly, I am not an engineer or engineering student. I come from an art/creative background. However, in what may be arrogance, I'm convinced I can solve a problem that no one but me thinks is a problem. Further, I'm spitting in the face of a system that has been fine for everyone else for...
I am currently trying to figure out how much power loss there is with a small transformer we have running VERY hot.
XF info:
5kVA
120/208 to 277V
%Z:5%
I can't recall any power equations dealing with real transformers.
Hi guys,
I am trying to calculate the power and temperature lost from a cable. So I can do some crude thermodynamic calculations on heat transfer.
I am assuming in this case that the object next to the cable is touching, and I am trying to calculate how much power and temperature is...
Here is the problem:
http://postimage.org/image/1jy6nol5w/
Method 1:
Steps
1. Calculate V(T1)=12*10=120V,
V(T2)=10*10=100V
2. Since V(3)=10V and I(3)=1A, P(T3)=10W
3. Since not otherwise stated, Assume transformers are perfect.
4. So P(T3)= P(T2) = 10W
5. known...
I have an experiment in which I have two solenoids where one induces an EMF in the other. I then introduce copper plates between the two coils and measure the decrease in induced EMF in the second solenoid. How could I calculate the power loss due to eddy currents induced in one of the copper...
Homework Statement
I am investigating the penetration depth of eddy currents within a copper slab. A solenoid is being used to induce the eddy currents within the copper. As a result of the experimental design, I need to calculate the power loss due to the eddy currents and I can't find any...
Homework Statement
In my electromagnetics book, in the section that talks about loss tangents, the equation for average power dissipation per unit volume is P=(1/2)*J*E (W/m^3). What does the coefficient of 1/2 come from? Earlier in the book, it gave the differential power dissipation dP=...
Hi all, :rolleyes:
I am trying to calculate the loss in power of a wave which is partially
reflected and partially transmitted from a wire.
The skin depth of the wire is many times the thickness of the wire.
My first attempt to solve this problem was to consider...
I found in a book the equation for the power loss caused by the heating effect of current in the transmission lines as below:
Ploss = Iloss2R = (Pout/V)2R
A friend of mine commented that the last bit "(Pout/V)2R" is unnecessary, confusing and wrong (but won't tell me why).
Is my friend...
Homework Statement
A 10/1 stepdown tranformer has a full load secondary current of 50A and is rated 30kVA. The copper loss at full load is 280W. The primary winding has a resistance of 0.25ohms. The core losses are 120W.
Find the resiatance of the secondary coil and the power loss in the...
Dear guys
I need assistance regarding optimization problem.
I have to minimize the power loss in worm gear drive system.
I have formulated minimization function,and constraints,how to solve the function and find design vectors.
ANy suggestions,sites,ref.welcome
Thank u
Prakash
Homework Statement
A 750-MW power plant sends its power out on a 475,000 V high-voltage line. If the total resistance of the line is 0.65 Ω, what percentage of the power is lost due to resistive heating?
Homework Equations
i have NO idea but maybe...
P(loss)=I²R
P(loss)=^v²/R...
Homework Statement
Well, I´m doing a project about FSO (Free Space Optics), it deal with optical communication but without fiber, only by air. Then, I have already studied the transmitter (gaussian source), the channel and I know I need a photodetector APD for the receiver but my questions...
Edit: My question is better expressed in my next post so ignore this post.
Homework Statement
A power station delivers 890 kW of power at 12 kV to a factory through wires with total resistance 5.0 \Omega
How much less power is wasted if the electricity is delivered at 50 kV rather than 12 kV...
Homework Statement
A 300 MW power station produces electricity at 80 kV which is then supplied to consumers along cabes of total resistance 5.0 ohms. What percentage of the power is lost in the cables.
Homework Equations
P = VI = V2/R
The Attempt at a Solution
I said the total...
Homework Statement
A high-voltage transmission line with a resistance of 0.345 ohms /km carries a current of 1.05 kA. The line is at a potential of 600 kV at the power station and carries the current to a city located 173 km from the power station.
A>What is the power loss due to...
Homework Statement
A power station delivers 890 kW of power at 12 kV to a factory through wires with total resistance 5.0 \Omega.
How much less power is wasted if the electricity is delivered at 50 kV rather than 12 kV?
Homework Equations
eq-1) P = IV
eq-2) P = I2R
Ohm's Law...
The power loss is given by I ^2 R where I is the current and R is the resitance.
I know why these variables are in this equation.
V = I R
P = I V
therefore,
P = I² R
What I don't understand is the practical explanations for this. Why are there two current variables? Are there two...
Power station generates 120kW
Electricity can be transmitted either at 240V or at 24000V using a step-up transformer.
The cables have total resistance of 0.4W
What is the power loss when voltage is transmitted at:
1) 240V
2) 24000V
I AM SURE YOU CAN WORK THIS OUT USING I...
Homework Statement
a power station delivers 520kW of power to a factory through wires of total resistance of 3 ohms ,how much less power is wasted if the electricity is deliverd at 50,000V rather than 12,000V
Homework Equations
P=IV=I^R =V^/R
The Attempt at a Solution
I tried to...
Homework Statement
A high-voltage transmission line with a resistance of 0.30ohm/km carries a current of 1050 A. The line is at a potential of 670 kV at the power station and carries the current to a city located 164 km from the station.
(a) What is the power loss due to resistance in the...
Show that the power loss in transmission lines, PL, is given by PL = (PT)^2 X R/(V^2), where PT is the power trasmitted to the user, V is the delivered voltage, and R is the resistance to the power lines.
I don't even know where to start. I am so confused by this chapter, I don't know what...
-A transmission line has a resistance of 5 ohms. Calculate the power loss in the line when 10 000 kW are transmitted at 10 kV...
I don't know where to start, what formula am I supposed to use? I'm sure the second I find out its going to be soo easy, but any help would be apreciated.
Thanks...
ok consider the circuit. what is the power loss in the 20 ohm resistor in J/s?
ok so what i did was that... and i don't know where to go after... please help