Power Systems Simulation - Science topic

try this one: https://pypsa.org/

To increase the voltage above 100% (1 per unit), you need to modify the design value (%V) as depicted in the figure attached.

You can use software such as Draw.io, but Microsoft Visio is undoubtedly the best for this kind of specific work.

Hi Dear

you can use this link:

thank you

Also check https://www.modernpowersystems.com/features/featurewhen-things-go-wrong-identifying-combined-cycle-problem-areas/

Material type

Climate

Rated voltage levels

.

For more details ,we have these articles:

1- Optimal distributed generation allocation in distribution systems for loss minimization

Authors Karar Mahmoud, Naoto Yorino, Abdella Ahmed

2- Advanced Pareto Front Non-Dominated Sorting Multi-Objective Particle Swarm Optimization for Optimal Placement and Sizing of Distributed Generation

DOI: 10.3390/en9120982

Dear Abdollah Younesi

See these articles:

1-Nonlinear dynamic analysis of a single-machine infinite-bus power system

Article Nonlinear dynamic analysis of a single-machine infinite-bus ... 2- PSDAT: Power System Dynamic Analysis Toolbox

Code PSDAT: Power System Dynamic Analysis Toolbox

Best regards

See these articles:

1-Nonlinear dynamic analysis of a single-machine infinite-bus power system

2- PSDAT: Power System Dynamic Analysis Toolbox

Best regards

I am an expert using PSS/E but I did not understand your question well.

If you mean how to make an equivalent for a 132kV grid, this done by using an equivalent load and generator as well!

regarding

I did not find yous in etap

Hi! please see the attached file below in V30.

You don't need to remove the row. you can, it wouldn't cause an error, but you don't need to.

One of the columns in the mpc.branch matrix is a "status". if it was "1" then it means the line is connected (on). if you change it to "0" it means the line is disconnected (off).

check the MATPOWER manual.

Dear Umair,

Verification can be done by using another tool to make the calculations when the results agree then your calculations were done correctly.

In order to validate your results you have at first to solve a known system.

The ultimate method is the building the system and measuring its performance parameter or simulating an already measured system.

Best wishes

Hello, try to save the txt file as excel format.

Hi Im tuning 4 VSC stations for a HVDC grid, modulus optimum and symmetrical optimum. works????

Did you completed the series parallel connection in simulink?

Hi, anyone can send the snapshot image for DFIG model in Digsilent?

The list will be helpful, especially if they are categorized by the type and application. If there is an overarching organization for simulation software (government or commercial), a link to that organization or main points of contact can be useful.

As you probably noticed, Scilab has very similar syntax to MATLAB, but still not the same. Some things, such as inline function definitions and fixed variables (%pi) are even tidier in Scilab in my opinion. Regarding plots I never had issues. In my opinion, the biggest downside is that Scilab has way less toolboxes than MATLAB. Historically it was also way slower, but that has improved by now.

I would recommend you to take a look at Python. It has a lot of momentum and is becoming more popular than both packages. With IDE Spyder you will get similar environment to Matlab or Scilab, with integrated figures and variable lists. It has plenty of libraries for numerical computing, such as SciPy, NumPy, Pandas etc... To sum up, there is also PyPsa library that is used for power systems simulation.

Some of the answers posted here so far have, I think, rather missed the point; but then, so did the question. The salient point is that the 'opposite' of 'magnetic' is not 'electrostatic' but simply 'electric'. Forget the term 'electrostatic', as that is just misleading. Conventional so-called electrostatic generators are designed to generate high voltages (for 'static electricity') rather than power. If we want to generate power then we simply look to the electric analogue of a magnetic power generator. As I will demonstrate, electric machines are theoretically much better at generating power than magnetic machines; but there are good reasons why they have not caught on.

Consider, first, how a generator works using magnetic induction. A moving magnet (relatively speaking) causes a time-varying magnetic field which generates a voltage in a loop of wire. If you complete the circuit to allow a current to flow, you dissipate energy and this arises because of the energy required to move the magnet against the field induced in the loop. A magnet is manufactured by allowing a material to 'solidify' in an area of high magnetic flux, so that the magnetic domains are 'frozen' in place.

A magnet is, more formally, a ferromagnetic material. Now consider the electric equivalent of a magnet, which is a ferro-electric material, also known as an electret.

A moving electret causes a time-varying electric field which generates a current in a wire/plate. If you complete the circuit to allow a potential to build up, you dissipate energy and this arises because of the energy required to move the electret against the field induced in the wire/plate. An electret is manufactured by allowing a material to 'solidify' in an area of high electric flux, so that the electric domains are 'frozen' in place.

The analogy is interesting, yes?!

Although 'magnetic induction' is the more familiar phenomenon, you will probably have done physics experiments at school with 'electric induction' using an electrophorus, which is a device for transferring electric charge from a reservoir. One of the key points in those physics lessons was to get the pupil to explain why it apparently allows you to transfer charge indefinitely, i.e. where does all the charge come from? That’s a very clever question, and it baffles most students, but it is only like asking why a magnet lasts 'for ever'.

Now, the energy storage density of a magnet is simply ½ B.H which, for a NdFeB magnet with a relative permeability of about 1 and a saturation flux density of (say) 1.3 T [Tesla, equal to As/m^2], gives about 0.8 MJ/m^3. The energy storage density of an electret is, similarly, ½ D.E which, for barium titanate, with a relative permeability of about 200 and a saturation flux density of 0.16 Vs/m^2 [that unit has no common name, unlike the magnetic analogy], gives about 7 MJ/m^3.

So you can see that – contrary to what others have said - an electric generator could be ten times better than a magnetic generator for the same volume of active material. So why do we not use electric generators?

Well, of course, they are used. For very small devices (not necessarily "nano" but just "micro" or "milli" devices) they work much better than a magnetic generator because they do not require a bulky copper coil to be added to the assembly.

However, for larger devices there are a number of engineering reasons why they are not used. To achieve the theoretical maximum flux density in an electret requires a very high electric field strength and, due to the breakdown voltage of the material, this limits it to a thickness of perhaps 1mm - so large devices are not practical. There are several other reasons, including those of cost, and of 'historical investment' by which I mean that there is a large body of knowledge on magnetic generators and no real incentive to find an alternative – except for specialised and very small devices.

Hope this helps!

Nitish

1. It's an infinite bus, so frequency changes don't come into it. Hence I don't think you need to model the infinite bus source with governor droop (sorry Arun).

2. I'm with M. Lima: a GENCLS synch machine model with H=0 is the best & simplest representation to an InfBus source.

3. A useful equivalent system model for the scenario you describe connects the InfBus source to the test network via 2 (or more) circuits with impedance chosen to reflect the pre- and post-fault infeed MVA. Then a fault on one, cleared by tripping it, simulates the change in post-fault conditions.

4. It doesn't matter what base MVA you choose (except to change the numeric values). Pu on test network base is OK, just so long as you make the connecting circuit X pu on the same base

For islanding detection, sometimes RMS rate of change of voltage is used. We have used in one of our publications.

We did a manual calculation in air before in

In the mentioned problem. tools such as the Power System Toolbox (PST), or the Power System Analysis Toolbox (PSAT) are more easier than the SimPowerSystems toolbox for an elaborated small-signal stability analysis. In addition, they are open source tools i.e. you can modify their liberary models, and add new models.

EMTP, DIGSILENT and MATLAB/Simulink on performance basis.

It is workable to create required Model in EMTP and MATLAB /Simulink, if you have compact knowledge.

Analysis is Superior in EMTP.

Help is available at Math-works in case of MATLAB /Simulink.

DIGSILENT is more professional tool and gives more credibility to your results on tool's end.

So kindly find out a trade-off according to your needs, circumstances and available tools/facilities.

May be this link can be a help 

https://www2.ee.washington.edu/research/pstca/pf118/pg_tca118bus.htm 

Kindly check, whether something from the following paper would be helpful to you.

Athbel Joe, and S. Krishna, "An Underfrequency Load Shedding Scheme with Minimal Knowledge of System Parameters," International Journal of Emerging Electric Power Systems, vol. 16, no.1, pp 33-46, Feb. 2015. (doi:10.1515/ijeeps-2014-0108)

Kishore you can use some voltage stability index as your fitness function. Thus you can use the system parameter  and the nrpf  solution in your code.

The load price depends on ISO that is supplying the area in question. So, you can find the data on their sites. For PJM for instance, the site is:http://www.pjm.com/markets-and-operations/energy.aspx

and you can find nodal prices vectors.

Yes, DIgSILENT PowerFactory has the DGS, it is the abbreviation for “DIgSILENT Interface for Geographical Information Systems”.DGS (DIgSILENT) is PowerFactory’s standard bi-directional interface specifically designed for bulk data exchange with other applications such as GIS and SCADA, and, for example, for exporting calculation

results to produce Crystal Reports, or to interchange data with any other software package. See more details on Chapter 22, Interfaces a the PowerFactory User's manual. Regards FGL

Hello Nabil,

To avoid any misleading answers, I would represent the problem at first.  

I understand your problem as following, you have made dynamic simulation (against time). For each step of time you have load-flow (or circuit analysis).  Now, you need to optimize the system parameters like injected power or even switching. In that case you have to go in one of two ways. First, you have statistical data and go for optimal solution expected. Second, solve the system several times for optimal operation, using some evolutionary algorithm like genetics.

In both cases you need to make the optimization technique first, then embed your system as a block not the opposite.

If my understanding is correct, kindly let me know that may lead to some steps forward.    

Dear Athira,

refer to the follwoing link:

Dear Kaylani, this paper answers your question: http://www.itee.uq.edu.au/pssl/drupal7_with_innTheme/sites/default/files/Test%20system%20report%20(1).pdf

Most modern wind generation technologies have voltage control capability, so these are not PQ buses in power flow analysis. You should represent them as PV buses. Now, depending on the technology, the reactive capability limits might be different. 

Also, note that often the voltage control is implemented as a wind plant centralized control, that controls the setpoints of the individual wind generators to meet voltage control requirements at the point of interconnection. Having said that, it is significantly more difficult to represent a wind plant (dozens or hundreds of individual units) in great details without also, somehow, representing this centralized voltage control. 

The PV bus approach would work reasonably well for the aggregate response of the wind plant, as seen from the point of interconnection,  though. 

1- THE EFFECTS OF POWER SYSTEM HARMONICS ON POWER SYSTEM EQUIPMENT AND LOADS, IEEE Transactions on Power Apparatus and Systems, Vol. PAS-104, No. 9, September 1985.

2- Understanding Power System Harmonics, Grady/Santoso, September 1, 2001

PSO codes in MATLAB is available here;

use the same example as it is very effective for your problem.

It is a PSS/E power system simulation software developed by Siemens.

thanks Mr Jesús Rodríguez-Molina

a) the error traces back to the battery control subsystem, from the battery voltage measurement, and nothing to do with the super-cap yet at least. 

b) checking my super-cap block I have no parallel capacitors.

c) I did change the solver from ode23tb which I used successfully for the equivalent simscape model. It was throwing that error for that as well

c) both with my prior equivalent simscape, and through my research having a power gui block within each subsystem is allowed. 

Hi Hitesh,

Your answer will depend on the region you are and the electricity operator (ISO) for that specific region. Let's say for Berlin you have to find who is the regulatory body that manages the electricity market and transmission lines. They have a database of all available generation sources and their respected capacities and in most cases they will grant access to that database. 

Cheers!

You can also use MATLAB and promote ready examples , to achieve the simulation.

You can use DIgSILENT educational low cost  version with 50 buses! Fabio give you a paper with model. Model use one dimensional vector fro P and Q versus time.

Dear

I think this paper will be useful for you

regards 

Zahir,

Just as a clarification, what do you imply by "regenerate" ? 

-Sanjay

Akhilesh,

If you wish to simulate the growth of oscillations as in time domain waveforms then PSCAD/EMTDC can help adequately.

But since you wish to do small-signal stability, you may need stuff like eigenvalue based analysis and design, or participation vectors - stuff for which you may need other software.

-Sanjay

Ishan ,Acording to my perception..... by using stack insulators you can increase leakage resistance and will get required current e.g. metal -insulator 1-insultaor 2 - metal 

As I vote on the first answer DIgSILENT PowerFactory !!!

Srete

Can you be more specific . Since you deal with turbine do you think of governor regulator. What is injector and deflector?

Srete

Hello Sam

You can go through this material, may b it will help to modify the state variables...

The most important thing is that your power supply is a voltage source, in the sense it must have a small internal resistance other wise you have to use a voltmeter to measure its voltage or better you measure the directly the voltage on the solar cell.

If you display your I-V curve one can easily judge the correctness of the measurement.

Otherwise every thing is okay.

Best wsihes

thank you Samundra Gurung 

Should be potential changes near the membrane, reflecting the kinetic barrier for ions to enter/exist the membrane.

I hope this website may be helpful

Develop a logic which can import data from .xls file to matlab then fed them into OpenDSS through DSSText.Command using COM interfacing.

Another platform to discuss this issue (follow the link) https://sourceforge.net/p/electricdss/discussion/861976/

maybe i can help you but need more explanation what you want exactly!

Try using Yn instead Yg on the transformer and connect the source N and the transformer N together.

Hello Marc and Sanjoy. I've found out the origin of my problem: deficient energy recovery path for the "lower capacitors". It produced a gradual discharge and unbalance in the voltage levels. That's why the system worked when I tested it with DC sources: they don't discharge. 

I solved the problem revising the diagrams. All working well now.

Thank you for your cooperation!

You need to create a new .m file with the content [D,h, c] = LENnumeric( q, qd, qdd, Baxter_l ). If all the required variables are in the workspace, it should run. You cannot run the file LENnumeric directly from the editor. Since it is a function you have to pass the required variables to it (even if they do exist in the workspace).

Simulink blocks use programs to give their output. Load flow calculation, load forecasting, and optimal power flow certainly a very complex phenomenon which is difficult to solve using just some blocks available in Simulink. However, ETAP, Open DSS, MATPOWER can have ability to do such studies.

The width of the signal remains unchanged. 10THz=1/10^-13

You have to know the frequency response of the channel. Impulse response or a step response. This problem identifying linear dynamic system.

I do not know how to measure these short pulses. It is almost an optical range. Look here DOI:10.1109/CLEOE-IQEC.2007.4387090  A. Bartels  All-Optical THz Oscilloscope

click on the link  it may helps you

Hi Pouya,

Yes, but the system parameters provided are realistic and authentic !

If required, a user can always split the unbalanced parameters into positive, negative, and zero sequence impedance or admittance matrices; and thereafter use only the positive sequence parameters for balanced studies.

Anyway, that was only a suggestion. Perhaps balanced data may be available from other sources - one can try !

With best wishes.

-Sanjay

As measured on the metrological scale, what you are exactly looking to estimate is the microclimate of the station which would depend on several constraints rather than only temperature and humidity.  The NOCT of cell in strings should be similar but again, it depends on surrounding vegetation/ water bodies. The model could be implemented on an approximate GHI. 

 Hello Anand,

There is High-Resolution Solar Radiation Datasets developed by Natural Resources Canada that shows  30-100 Hz or up to once every 10 milliseconds distributed among two systems at two Canadian sites. The first system is located in Varennes (Québec), and the second in Alderville (Ontario). You can get these data free from Natural Resources Canada website :

Moreover , There are also some several  solar resource data currently available for Canada. Some of them are in high resolution time including 1 minute- 30 minutes hours etc..

Historical averages and other statistics are available, as well as time series data starting as early as 1953 and extending up to near real-time. Some data is publicly available for free, while other data must be purchased (as indicated by “$” in the summary). you can find these in the following website :

Good luck in your research .

Hassan 

hI

I presume that this is typical RDN(Radia Distribution Network) at  the secondary distribution feeders supply residential and commercial customers at 120/240/440 volts.

In general, the distribution system is the electrical system between the substation fed by the transmission system and the consumers’ premises. As for  f the current case the voltage level  is set for 220-240 V, it is require to maintain requirements for such type distribution in order to guarantee consumers power rate requirement mainly the proper voltage, loading  and reliability issues.

RDN unbalanced are prone for Dynamic change in imposed load, High R/X ratio, and contain also extremely large number of nodes and branches.

You might find Ladder network methods implementation in some section of  the system in order to finds suitability and practical application for single source radial structure networks with high R/X ratio;

You may also use  SVC or Series compensation at substation fed in order to regulate voltage and  Reactive power correction.

i suggest to follow   the below link as well...

Grounding is a North American term for Earthing in the European Continent. They have the same technical meaning globally.

IEC standard 60364 defines TN and IT systems as solidly earthed and unearthed electrical distribution systems (normally for low voltage - i.e., below 1,000V a.c. or 1,500V d.c.)

Apart from Norway, almost 99% of other countries use TN system for public distribution systems. This is because an earthed system has the following main advantages over an unearthed system;

An IT system is normally used only where there is a requirement that under a first earth fault condition, the supply should not be interrupted and shall still be able to provide a continuous service to say one or several pieces of essential (e.g., life-safety or fire-protection) circuits.  Instead of immediate disconnection of the circuit or equipment under a single earth fault condition, since there is no earth return the faulty circuit will remain in working condition, there will be earth fault monitoring device to raise the alarm that an earth fault has been detected. This allows e.g., the hospital staff to bring in a new piece of standby equipment, set it up and have it working before replacing the faulty piece of equipment.

If you want a very continous DC supply current, I would use an LC filter in the DC supply.

Cheers guys.

Hello Brijal Mehta,

LinkNet is one type of linked listed used to store and perform calculations involving sparse matrices. I have a few notes I lectured from on Linknet, which I may be able to find if required. We used LinkNet extensively here (due to R. Podmore coming from the University of Canterbury) but have more recently use bifactorisation by Zollenkopf  [1].

[1] K. Zollenkopf. Bifactorization: Basic computational algorithm

and programming techniques. In Oxford, editor,

Conference on Large Sets of Sparse Linear Equations,

pages 76–96, 1970.

Hello Adel Alganidi, 

I can understand your difficulties dealing with the modelling of power system specially for studying damping performance. I had to go through all those modelling steps too. 

Studying damping in a power system involves the study of of power system stability. That's the most complicated thing i had ever experienced during my study period. Modelling a complete power system is a nightmare in case of multimachine power system. The complete system modelling includes turbine, governor, exciters etc which are quite difficult.  Therefore, its good idea to avoid those complexities as much as possible by finding alternate options. 

The damping studies can be conducted in two models of a power system.  Those are linear model and non-linear model. The state-space is the linear model which gives you idea about the damping of dominant modes (for experts only). On the other hand, non-linear model give you the visual experience of damping performance in terms of overshoots and settling times. That's pretty good for impressive presentation.

You need to model the system into state-space form. The State Matrix 'A' give you the system eigenvalues. That' all you need to study the stability of your power system. The system eigenvalues obtained from State Matrix 'A' will then be used to determine damping factors and damping ratios. That's the things you need to get in order to study damping in a power system.

Therefore, my suggestion is to use ready mate toolbox which are recognized and standard for power system stability study.  I found 'Power System Toolbox' by Dr. Kwok W. Cheung and Prof. Joe Chow as the most suitable and comprehensive tool for such study. In addition, i suggest you to read the book 'Power System Oscillations' by Graham Rogers. You can find the toolbox and book here

Toolbox: http://www.eps.ee.kth.se/personal/vanfretti/pst/Power_System_Toolbox_Webpage/PST.html

Book: http://www.springer.com/us/book/9780792377122

You can find more information regarding this on my publications. Here are two publications that may help you further

If you need further details let me know. I am happy to help you in my free time. 

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Note: if you are satisfied with this reply, please upvote it to spread quality contents. 

price is depends on rating of the equipment and brands. this is vary from US $50,000 - 350,000 / Unit.

Power consumption of system = (numerical value) W

Running time of air-conditioning = (Time) hours

Total consumption = (Power consumption × running time) Wh

Peter gave very good pointers.

If you need that kind of logic in other high-level programming language like C++, try googling for a library implementing it first.  If you don't find anything, you would need to write your own user defined class based on your chosen logic axioms (or specifications like IEEE). Should you go this way, I strongly suggest that you do it in a Test Driven manner (a la TDD) to cover all cases with tests.