What is Power system: Definition and 51 Discussions
An electric power system is a network of electrical components deployed to supply, transfer, and use electric power. An example of a power system is the electrical grid that provides power to homes and industry within an extended area. The electrical grid can be broadly divided into the generators that supply the power, the transmission system that carries the power from the generating centers to the load centers, and the distribution system that feeds the power to nearby homes and industries. Smaller power systems are also found in industry, hospitals, commercial buildings and homes. The majority of these systems rely upon three-phase AC power—the standard for large-scale power transmission and distribution across the modern world. Specialized power systems that do not always rely upon three-phase AC power are found in aircraft, electric rail systems, ocean liners, submarines and automobiles.
Hello there! I am using a Surge Protection Device (SPD) for Solar Power System. My home uses a 3-phase system (380V and 220V at each phase). What should be the tension between the phase and ground at the SPD? And between the ground and neutral? Should be any tension at all? God bless all. PS. My...
Hey everybody,
Its recurrent in Power System Analysis and Electrical Instalations the SL diagram. I need recommendations of books in which I can read about it. I've done a little research but couldn't find anything. Thats amusing, in which classes are this diagram teached for the first time...
Homework Statement
It's a solved problem but I don't understand why is there no 30 degree lag from line voltage to lead voltage.
Homework Equations
Phase voltage = Line Voltage / 1.732 and there is 30 degree lag
So shouldn't Ir be at angle 150 degrees.The Attempt at a Solution
In Y line and...
I'm studying Newton Raphson Method in Load Flow Studies. Book has defined Jacobian Matrix and it's order as: N + Np - 1
N = Total Number of Buses
Np = Number of P-Q Buses
But in solved example they've used some other formula. I'm not sure if it's right.
Shouldn't order be: N + Np - 1
N = 40
Np...
Homework Statement
Homework Equations
If load is inductive current lags voltage. If load is capacitive voltage lags current
The Attempt at a Solution
Current lags voltage since wire is inductive.
So IF1 lags VF1 and IF2 lags VF2
But book says answer is C
Why should VF1 lag IF1? This will...
There are three geothermal systems that are commonly used: sry steam, flash steam, and binary cycle https://www.eia.gov/energyexplained/index.cfm?page=geothermal_power_plants . What are the efficiencies of the plants from best to least effecient on average?
I'm working on modeling a basic mechanical power system for a video game project. The transfer system consists of meshing gears, belts, and axles/shafts which can have basic clutches that engage/disengage. There are also power producers (hand crank, windmills, water wheels, turbines) and...
Hi again, got a few questions (marked with numbers) for passive filters used to filter harmonic currents in the power system.
Look at my one-line diagram below. Let's say I have a passive filter connected in shunt with respect to the load and the passive filter "diverts" the harmonic currents...
Hello, I've been building my own solar panel system and throughout this process I've accumulated a lot of questions. If anyone could help answer them I would greatly appreciate it!
First I'll start off explaining what I have.
A polycrystalline solar panel 17V 2.2A and a mono crystalline panel...
Hi,
I want a book about power system analysis that I can have laying around and read from time to time. I have taken a course in power system analysis some time ago, where I was taught simple fault analysis including unbalanced faults, frequency and voltage control.
So to maintain this...
I read in a book that during normal working condition (balanced system) the current through a neutral conductor is zero i.e., Ia+Ib+Ic =0 where Ia, Ib, Ic are phase current of three different phases a, b, c. How is that possible? I mean if you look at mathematical result of the phases they are...
Homework Statement
A 400 kV transmission line has a length of 500 km and a reactance of 0,4 Ω/km. How much power can you transmit, if the power angle (the angle between the voltages of the beginning and the end) is limited to 25 degrees? What would then be the line’s boundary power limit for...
I am trying to understand the solution provided to a numerical problem based on reactive power compensation.
Here's the problem:
Two buses A and B are connected by a transmission line of reactance j0.5 pu. Voltages at both the buses are 1 pu. Bus A is connected to a generator. If the complex...
ALFC and AVR are used to maintain grid frequency and grid voltage constant w.r.t. changes in real and reactive power. Real power has a direct effect on frequency while reactive power has a direct effect on the grid voltage.
Consider a power system running at normal grid volage with rated...
Hello.
I need to simulate a power system including conventional generators, loads and wind farm. I want to measure system frequency and voltage esspecially. According to these values for any kind unwanted of voltage and frequency changes circuit breaker should be opened and wind farm will be...
Hi,
imagine we have the following circuit shown in the figure below. There are installed a passive filter to filter the 5th harmonic. Now, after installation this creates a parallel path with a generator connected, let's say that this parallel circuit has a resonance frequency at the 7th...
I am studying ALFC and I have a few questions about it.
Consider the flyball governor in this system. It senses the changes in speed of the turbine. If load is increased, the balls will slow down and will move inwards, moving point B upwards. Now, this will open some additional valves to allow...
Homework Statement
I'm doing an assignment on cathodic protection systems using solar energy and have no idea on how to construct an efficient system. All the ones online are too basic and don't specify whether the panels are in series or parallel or not. I've calculated that the system needs...
I recently read a chapter on power system analysis in a book and I have some questions.
1) The three phase power at the secondary distribution level is unbalanced i.e. not equal for each phase but it is nearly balanced at the HV transmission level.
Is this true? Also, is the power balanced at...
Hi,
could anyone explain to me how odd harmonics in the power system are reduced or removed? I've read that in transformers the harmonics produced by the load circulate if the secondary side is wired as delta configuration, yet star is usually used on secondary side i believe?
I've looked...
Hi. I am an electrical engineering student in my final year. I want to write a research or review paper this year before completing my degree. I haven't written any paper before. I don't know where to start. Will someone please guide me? In addition to that I haven't selected any topics so I...
Homework Statement
Calculate the solar array power capacity required at the start of the mission
Mission duration is 10 years
Distance from the Sun at end of mission is 4.8x[10][/8] km
The power requirement for the spacecraft at the end of life is 510 W
Solar array degradation over mission...
Sorry for bad title(little informative regarding my question), however I came across the following question given as an exam question at some university.
Question:
"A synchronous generator is running overexcited with excitation voltage Ef = 1.40 p.u and connected to the network at voltage of 1...
Now a days in most of the power systems(generation,transmission (HVDC, HVAC) and distribution) we use semiconductor devices for efficient use of power.using power electronic components in power systems does it affect the stability(transient/steady state)?
My background is mechanical engineering so not great with the electrical side. I plan on buying a air-preheater (resistive wire heated) which has a power rating of 30kW, supplied by 3-phase. I need to determine whether my 3-phase supply (415V 32A) has a max current that can cope with this. My...
Homework Statement
https://dl.dropboxusercontent.com/u/88040310/powerhw3.png
1. Draw the reactance diagram.
2. Calculate the per unit impedances
3. If bms #1 is operating at 30 kV, find the current
Assume base of 100 MVA, 300 kV on the generator side.
Homework Equations
P = VI
s = p +jq...
Could somebody please suggest me a staff mentor, or perhaps anybody, preferably a power system engineer and into hydro power.
i really need some help.
thank you :)
Hello
I am interesting in transformers lately, and I noticed that most commonly used method for representing transformers in power systems is by symmetrical components.
Now, I am wondering - is there any way that we can represent and calculate transformer in phase system, totally without...
If you have a purely resistive load, which is connected to the generator via elements such as (transformer, transmission line etc), will the load power factor still be unity or 1.0 (In theory)? Or do the previous components such as transmission line etc affect the load power factor? Many Thanks...
Hi,
I'm kind of struggling on finding information regarding the transfer of 1000MW to a load located 500km away.
As far as 400kV transmission line is considered I can't find a design similar to these therefore would anyone be able if the following would be correct:
Assumption:
(using...
"Harmonics in polyphase power system"
Dear All,
I have a problem in understanding how the harmonic currents exist in a load with no corresponding harmonic voltages?
The following figures with questions under explain what I mean
This understood figure no issues about.
In above figure, 2...
Can anyone help me with finding good ideas ( or direct me to any useful websites /pages ) for Power system engineering projects !?
Suggestions are highly needed , ASAP !
my appreciation in advance to you .
Hello!
I hail from the land of motorcycles, and I have a power generation issue regarding single-phase vs 3-phase system design. I'm well beyond my specific area of expertise, but need to choose a system wisely, as I travel on my bike off-road and well beyond civilization and prefer not to...
Hello everyone!
I've been searching everywhere for useful info about this topic, but I haven't been able to find anything.
My question is: Is it viable to tune a PSS by using time domain?
The thing is, i don't know how you can associate the frequency range in which the PSS is needed for...
I am using the "Three-Phase PI Section Line" Matlab-Simulink block from Simpowersystems blockset for modelling an electric power system transmission line.
I had obtained the data from a research paper regarding the transmission line specifications (provided as sequence values).
Since I am...
Hello everyone,
I am new here and I really really need someone's help.
I am studying the operational issues that could arise when connecting a windfarm to the grid. I have drawn a circuit model and it is the one I will use for the study. I am stuck with the circuit analysis. I need to...
Perhaps sb is able to point in the right direction. The task is to calculate the value of the receivig end volatge, for a load of 10 MW at 0.9 pf taken from 66 kV substation.
First I calculated the transmission line impedance
Zlinebase=(Vbase^2)/MVAbase
Zlinebase=132^2/100=174.24Ohm
Zlinepu=...
I appologize in advance if my terminology is flawed...
I'm interested in exploring how to produce power with a bicycle and have read a ton about it on the internet so far. However, I can't seem to find anyone running more than one motor from a single bike. I assume there's a good reason but...
HI guys,
I am grasuate student, i am planning to work on power system stability of Smart grid, i went through different books and papers and other sources and still i am confused to decide what is the basic measure of the stability of distribution system. I have this confusion over different...
hi, I am just not able to solve this problem in the generation part of electrical power system.
I am not able to plot the load curve and the load duration curve.sum is as follows:-
A power station has to meet the foll demand:-
GROUP A: 200 kw between 8 am and 6 pm.
GROUP B: 100 kw between...
Hello,
I have two 120V sources. One is inverter and one is normal AC from sticking contact. And i want only one of them as output. Output will be from inverter or 120V from sticking contact.
I want normal AC from sticking contact to be active. If it is shutdown so i want output will...
Homework Statement
http://img42.imageshack.us/img42/3537/powersyst.jpg
Homework Equations
P = I^2 R
The Attempt at a Solution
Here's what I have so far:
I1 = 49.68A<-68.6 degrees (top loop)
I2 = 49.68A<-128.6 degrees (bottom loop)
I3 = 28.68<-98.6 degrees (triangle loop)...
Hello,
I am working on building a wireless power system, I have looked into it a bit and the best if not only way seems to be a resonant air core transformer.
My primary coil/circuitry can really be infinite in dimension, but my secondary coil needs to be no more than 2 inches in...
I wanted to throw out a question and see what some general consensus/opinion on the Polywell fusion power system is.
After I first read about the precursor (Farnsworth fuser) and was initially interested greatly as I had similar thoughts before really researching fusion.
Personally, I'm...
I am working on modeling a power system on an aircraft right now, the problem is that I have loads that are constant power drawing no matter the voltage. They will draw 5kilowatts no matter 28 volts or 22 volts. My problem is modeling them. I can model them at one particular voltage but I want a...
:confused: I am currently working on a university assignment and am quite confused in the following design problem...
Assume that a new in a facility 3 new plants are being setup. 2 of these plants have all motors rated at 50 hz while the third one has all motors operating at 60 hz. the first...
I just want to clear up my understanding of rated power systems.
For example, if an electrical system is rated 5kVA at a nominated supply voltage and power factor does that imply that the total apparent power (S) supplied to the circuit must equal 5kVA?
Thanks.