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.
Using P = I2R
2502 x 3 = 187.5kW
Now, I'm pretty sure that this is correct but my question is how does V = IR fit in with this? So, I = 250 and R = 3 so V must be 750, but what does this 750 volts represent? A voltage drop between two points on the transmission cable? If so, where are the two...
Hi there!
Recently, I am studying this kind of power loss from the following link:
https://www.electricalvolt.com/2019/08/eddy-current-loss-formula/?expand_article=1
Just to summarize an idea,
Supposed that we got a material, which is penetrated by a magnetic flux. The material will generate...
I know how to solve the question but I am a bit confused about why there is a current of 3 A and a voltage of 110 V requirement for the refrigerator but the power plant only supplies 110 V.
How can there be a voltage drop on the refrigerator load of 110 V, when there is also a voltage drop on...
Hi there,
if a dielectric (capacitor) is described with a constant permittivit eps (or C) and loss-tangent DF, how much energy ist lost when charging the capacitor by 1V?
For example: C=1, DF=0.1.
When charging from 0 to 1V, the lost energy (in J) is ...?
When charging from 1V to 2V, the lost...
a) Output voltage = 2 x 6 = 12 V
Current in R = 12 V / 13.5 kΩ = 8.9 x 10-4 A
That is the correct answer based on the solution but I don't understand why when calculating the current in R, the resistance of secondary coil is not considered. I thought it should be like this:
Current in R = 12...
Hi,
So the main question is: How to deal with power loss in E-M waves numerically when we are given power loss in dB's?
The context is that we are dealing with the damped wave equation: \nabla ^ 2 \vec E = \mu \sigma \frac{\partial \vec E}{\partial t} + \mu \epsilon \frac{\partial ^ 2 \vec...
Intuitively I fell like AC would lose more power long a long power line than DC. I will use a model to explain my perspective.
Let me model a wire as a long straight, non-frictionless tube, about the diameter of a marble, filled with a row of marbles that are each connected to the one next to...
Hi. I'm having trouble with calculating
(8.59)
from (8.58)
(## \vec H_{//} ## is simply ## \vec H ## in Jackson, but that shouldn't matter.)
in Jackson. Specifically I think I'm not sure about parallel component of H field here.
For example, shouldn't I have two terms for the...
Well, I've been trying to design a microhydro power project, and I contacted a supplier on Alibaba and we're a bit at odds about the recommended transmission voltage, I'd like to go with 480V and a transformer back down to 120/240V on the other end, their 'engineers' say this isn't necessary and...
Homework Statement
Homework EquationsThe Attempt at a Solution
I have posted the whole solution so it is more complete, but I really only need help with part c (I think)
My output power is higher than my input power, I'm not sure where I'm going wrong
Hi there,
If I'm using the equation P_loss = P^2 * R / V^2 to calculation the power lost on a cable, where R = p(resistivity) * L(length) / A(cross sectional area), then how long is this power loss for exactly?
Thanks,
Sydney
Why is the equation Power Loss = I^2*R rather than Power Loss = V*I?
What I mean is why use I/R to represent V?
Also if Power Loss is equivalent to V*R, doesn't step up transformers which creating higher voltage also cause Power Loss to increase which contradicts to textbooks stating that power...
Say a power station transmits 1008 MWh of power per year to a facility however they only receive 900 MWh say the transmission line is 15 km long how would you calculate average power loss per km, now I know that theoretically it will just be 7.2 MWh per km but what calculations would you make to...
Hi
I'm trying to calculate the power loss over an electrical cable.
The information of the system is:
Maximum current of 20.92 A per unit at 34.5kV
The cable has the following properties:
DC Resistance at 25 deg C (0.1672 ohms/1000 ft)
AC Resistance at 25 deg C (0.1672 ohms/1000ft)
The length...
What could cause a laser source with fiber coupled laser diodes to have extreme loss of power? The laser diodes have a wavelength of 658nm and have an output rated at 60mW but it seems as though the optical channels actually output ranges between 58 to 70mW.
During some troubleshooting I...
Hi all,
I am recently calculating the iron loss in a permanent magnet synchronous machine with a speed of 24000 rpm (electrical frequency 800 Hz). However, the iron loss data from the data sheet is not sufficient since only frequency of 50 Hz, 100 Hz, 200 Hz, 400 Hz, 1000 Hz and 2500 Hz are...
[Moderator note: Thread moved from technical section hence no template. Question text from later in the thread added to this post to make things clear]
"A power station generates electric power at 120kW. It sends this power to a town 10 km away through transmission lines that have a total...
Homework Statement
A farmer installs a private hydroelectric generator to provide power for equipment rated at 120 kW 240 V AC. The generator is connected to the equipment by two conductors which have a total resistance of 0.20 Ω. The system is shown schematically in Fig. 1.
(a) The...
Homework Statement
Homework Equations
power loss = I2R
power loss = V2/R
The Attempt at a Solution
voltage across diode is 0.7V, current is 100A. resistance = 0.01 ohm.
Power loss is I2R - 100 * 100 * 0.01
= 100 W
Power loss across IGBT = V2/R. V across IGBT = V across Diode = 0.7.
R for...
Hello everyone, so I'm currently trying to find out how much power will be lost during reverse recovery of a MOSFET's diode. I'm using this paper for reference, https://www.fairchildsemi.com/application-notes/AN/AN-6005.pdf
the equation they end up with is
P= Qrr*Vin*Freq_sw
the problem is...
In a transformers output, is it the current that is fixed or the voltage?
I have been trying to resisitively heat some tungsten foil and I am stuck at trying to find out the amount of current I need in my transformers output. The problem I am facing is that I know that the tungsten resistivity...
Homework Statement
My textbook says that high voltages are used for power transmission because according to the equation P=VI and P= I2R, power loss can be reduced.
What confuses me is why the equation P=V2/R cannot used here? And if used, would be contradictory? I know that R is the...
Homework Statement
Consider the circuit shown below. a) What is the total power loss for the whole circuit? b) What is the power loss through R1? c) What is the power loss through R2? d) Find the voltage across each of the three resistors.
I didn't do this myself. I have no idea what's going...
Homework Statement
A 400kV line is carrying 1GW of power and experiences a line resistance of 5 ohms. What is the power loss in the cable due to resistive losses?
Homework EquationsThe Attempt at a Solution
You are given 4 potential answers to this question
a) 3.2x10^7 W
b) 78 W
c) 5000 W
d)...
A small factory has decided to go Carbon neutral and has installed its own wind turbine. The wind turbine is installed on land belonging to the factory 1 km away. The factory owner needs 2km of copper wire of diameter 3mm to connect the turbine to the factory. The resistance of the cable is 1.2...
Homework Statement
An electric fan which is plugged into a 115 V(rms), 60 Hz socket in your house can be considered as made up of a 1500 Ω resistor in series with a 1.4 H inductance. How much power is dissipated by this electric fan on the average? (in W)
Homework Equations
P = IV = I^2 R
I =...
Project : a solar panel powered LED light (with built-in storage battery) with the house facing north (in Canada).
Story : The kit is bought at Costco.
The solar panel is small (but it provided a 20 ft cable) and separate from the battery and light.
The light (motion and light activated) is...
Hi guys,
I have quick question about calculating the power lost in fluid flow.
So imagine there is a simple setup as in the attached image, where you know the mass flow in and out, pressures at inlet and outlet and the temperature at the inlet.
Is the equation to find the power lost or...
I was having a discussion with a friend, and my side of the argument was that for solar to work you also need a lot of fossil fuel running in the back ground just during the day, making it very expensive. Let's take New york as an example.
Let's assume they have enough solar panels to produce...
Homework Statement
2. Homework Equations
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I am trying to prove the equation
$$
\frac{\bar{P}}{V}=\frac{1}{2}E_0^2\sigma_{AC}
$$
which can be rewritten as
$$
\begin{align}
\frac{\bar{P}}{V} &= \frac{1}{2}E_0^2\sigma_{AC}\\
&=\frac{1}{2}E_0^2\ \omega\ \epsilon_0\ \epsilon^{''}_r\\...
Hey everyone,
This is quite a simple question, I think I'm just getting confused.
1. Homework Statement
Given Data:
Merlin: Resistance: 2 Ω / km, Maximum Current: 519
Pelican: Resistance: 1.5Ω/km, Maximum Current: 646
Penguin: Resistance: 4 Ω/km, Maximum Current: 357
Sparrow: Resistance...
Hello,
I have forgotten most of the electricity physics we studied and I have problem describing/understanding a concept.
Does AC current produce less loss than a DC current? I found this statement in a website: "AC electricity loses less power over power lines than DC"...
Howdy all!
In some project I do,I need to design belt transmission,now the tricky part is:
On the output of the belt,I have wheel that needs to turn at 700 rpm,and I need to deliver power of 6KW.
Now the weird question:I need to design the belt transmission so I will have 20 percent power loss...
Power loss doubt: power loss = I^2 R Power loss = V^2 / R But the 2 equations are contradictory ,,, from the first equation , we can say " MORE THE RESISTANCE MORE THE POWER LOSS" from the second equation ,,, it is the other way round... Why does this happen? ( usually the 1st equation is used...
I'm revising attenuation and power loss logarithmic equations.
The exam formula I'm given is attenuation = 10 log (I1/I2)
I'm trying to confirm what each I stands for.
Some of the examples I'm looking at seen to give input/output power, some seem to reverse it. Which is right? What do they...
Homework Statement
A factory receives 120kW of power from a power station 20km away via transmission lines. If the resistance in the power lines is 0.5Ω/km, what is the power loss in the lines if the electricity is transmitted at 100kV (Approximate to a simple DC circuit).
Homework Equations
V...
Homework Statement
A small power plant produces a voltage of 6.0 kV and 150 A. The voltage is stepped up to 240 kV by the transformer before it is transmitted to a substation. The resistance of the transmission line between the power plants and the substation is 75 Ohms.
What percentage...
Homework Statement
In Australia, New South Wale's final year of high school, a common question is asking something like:
How does distributing electricity at high voltages reduce power loss in the transmission lines.Homework Equations
P = VI = (I^2)R = (V^2)/R. Not very clear without...
Hi,
A current carrying wire creates a magnetic field around it, as shown here: http://courses.ae.utexas.edu/ase463q/design_pages/fall02/wavelet/3_sour8.gif [Broken]
As far as I am aware this usually doesn’t cause a power loss. Even if there is a flux on a nearby conductor there will be no...
Hello,
I'm working on a project at which a large amount of current is being passed through a low voltage system (48 Volts). In one part of the system, there are connectors rated at 12 Volts in which the 48 volt DC current is passed through. How much power loss might I be suffering here...
I was recently informed that AC is the preferred method of transmitting power because it suffers significantly less power loss going from the generating station to where ever it needs to go when compared to DC losses.
In my introductory electricity class we learned that power through a given...
Looking for a description of low efficiency in Rubber band or Tubing
I am looking for a description of power loss in that you don't get out the work you put into pulling latex tubing.
I have some new latex tubing that is treated with UV protection and is super hard to pull from the very...
The hydro meter for my house sits on a pole at the front of my property (5.5 acres) approximetly 200 - 250ft from my house I can't give you the wire size that runs under ground.
My question is: Is there a loss of power in the distance from the meter to the house and would this result in my...
Homework Statement
65 kW is to arrive at a town over two 0.100 ohm lines. Estimate how much power is saved if the voltage is stepped up from 120 V to 1200 V and then down again, rather than simply transmitting at 120V.
2. The attempt at a solution
First I want to find the power lost in...
Hey everyone, I could do with a hand checking my understanding of calculating the current loss in cables just to make sure I am doing it right.
First up, is power loss. From my understanding of ohms law and P=VI it is possible to calculate the power loss in cables by using the formula power...
Homework Statement
A 200m long copper wire, with cross section area of 1.5mm2, is connected with a 10Ω resistor in a series circuit, and the supply voltage is 50V.
Homework Equations
Find the power loss in the copper wire, when ρ=0.0175 Ωmm2/m
The Attempt at a Solution
R=*L/A...
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...