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Power System Stability - Science topic
Explore the latest questions and answers in Power System Stability, and find Power System Stability experts.
Questions related to Power System Stability
Do you think that the following online course covers all types of power system stability studies?
Most damping issues seem to arise from positive real parts, so I wanted to check:
1- Do these minimal positive real parts indicate any concerns?
2- Are they essentially negligible in terms of impact on system stability?
I appreciate any guidance you can provide to improve my understanding of their significance in the analysis.
Mostly FACTS devices are used to inject the reactive power into weak power system and improve the stability. Nowadays, we include more number of DG in power system. In this condition, does any instability condition occur? What type of instability occurs? Will using facts devices become possible or not?
hello all,
I want to design a Static Synchronous Compensator ( statcom ) in order to investigate its impact on power system stability but I found some difficulties in calculating some values like (the rating of statcom, DC-link capacitance, L, the voltage of tow winding of the transformer .... ext )
Any reference? Please,

It is well-understood that depends on the power system strength or system inertia in addition to the speed protection system settings.
I just would like to see some typical values for such imbalance either normalized or in MW.
Many countries have plans to deploy electric vehicle charging stations (EVCS ). As researchers, how do we start with that?, What about the expected issues that will occur in the power system and ways to solve them?.
I need to simulate it using MATLAB
I need research papers on the title power system stability enhancement using SSSC with full documentation and simulation. I am beginner
Do you think a virtual synchronous generator (VSG) can be used in a large power system?
Please explain your ideas.
Thank you for your participation.
What are the various techniques to predict missing data in power systems?
Mostly referring to the measurement data coming in from sensors or smart meters.
References are welcome.
Thanks in advance!
PMU data can go missing due to several factors - faulty PMU or PDC or communication channel, cyber attack, etc.
Bad data can be also caused due to some of the above reasons or maybe due to some valid reasons such as faults occurring in the power system.
But be the reason valid or invalid, the signal processing algorithm will consider the data to be missing irrespective of the cause and could treat it as a fault and can opt for control strategies accordingly.
My question is directed at gaining insights about how to identify whether the missing/bad data occurred due to a valid (fault, etc) or invalid reason (cyberattack, device failure, etc) by monitoring any other data from any other device or using any algorithm.
If you can share any references, it will also be quite useful.
Thanks a lot in advance.
Why power system stability studies are initialized using load flow rather than optimal power flow?
Does anyone have experience or ideas about the hardware design of power system stabilizers in a power system?
For more details about the converter interfaced generation and their impacts on power system stability, you may read
What are the available and recommended software tools for simulating these newly added dynamics?
Generator can be modelled using the Classical Swing Equation model as well as higher order models. What are the advantages (and disadvantages) when the order of the model is increased?
Is there any norm of which model we can choose for any certain application or studies?
Citing references can help.
Thanks!
My Greetings,
I have done research on Power System frequency control and stability specifically on microgrids. My inquiry is about Texas A&M University. If anyone know which faculty member works in the mentioned area. here is the link of the faculty members at Texas A&M University.
Introducing other US universities faculties will also be a plus and informative.
Your answer would be truly appreciated.
Mohsen




I want to simulate nonlinear state space equations, I need it for stability analysis.
So I have MVAsc rating given of an 132 KV grid which is connected to bus. The cable impedances are also given. The total load consumed is also given. How can I model 132 KV grid in PSSE? Can I do it with an equivalent generator? If yes how to estimate its capacity
Mostly, PLL is mostly employed to generate the phase angle of PCC voltage in grid-following controlled converter. However, the phase angle can also be directly computed from abc voltage (first do the clark transformation to alpha-beta than calculate the anti-trigonometric). The fluctuations of the result caused by harmonics can be filtered someway, i suppose. Isn't it an easier and more reliable way than PLL?
I am doing my Master Thesis about the Effect of STATCOM on the power system Stability using PowerFactory Software, Could you help me in the Software? as i want to simulate the Effect of the STATCOM in both Steady state and Dynamics cases.
Hello. I am working on the voltage stability issues of an actual large-scale wind power connected power system and am trying to simulate the occurences of three-phase short circuit faults at different parts of my extensively modelled grid mainly in places of high wind penetration. The problem is that whenever I am simulating 3-ph faults at some busbar that should bring down the voltage to almost 0.15-0.25 p.u. at it, the system is becoming unstable right at after the voltage drop or at the instant of the clearance of the fault with the RMS simulations throwing up errors like 'System Matrix Inversion Failed' or 'Equation System could not be solved. Check control conditions.' This problem is disappearing at relatively less voltage dips at the concerned buses (at around 0.3-0.4 pu and above). So I wanted to know if this is an issue with how the grid has been modelled in actual such that at severe voltage dips it becomes unstable, or is it because of an underlying issue in my modelling of the grid which I may have overlooked in the process. I have followed quite efficient dynamic modelling procedures of the wind turbines as per IEC standards and the conventional generators as per the usual standards. Any help regarding this would be much appreciated.
Can anyone help me to learn about designing WAMS based POD control for SVC or TCSC or VSC based HVDC?
I want to study the stability of a single machine infinite bus system with MATLAB. My problem is not in simpower systems, but in simulink.
why power system stability studies are initialized using load flow rather than optimal power flow?
I am working on Power system modles in MATLAB with some adaptive controllers. The simulation run for different time duration like 8,10, and 15 sec. Now i need to get the computational time taken by the computer to solve the iteration behind theses simulations. I found tic and toc command but need more detailed explanation to use it. Thanks
For example, if I want to find the stochastic OPF of a system, shift factors can provide a way to find shifted power for different scenarios. Therefore, OPF for each scenario is not required but only for base case. This will reduce simulation time. Please share relevant code if possible. Thanks.
The question arises mainly because traditionally the rotor-angle stability is defined for power systems with large rotating machines. But in LV system with large distributed generation, what we have is inverter coupled PV units, storage (also say inverter coupled), EVs etc.
So I want to understand how rotor-angle stability (and transient stability which is also coming from rotor-angle stability) is defined in such a situation. Can someone shed some light on this topic?
Why is a DC link capacitor required in a grid integrated renewable energy system?
Suppose we consider a single stage system with solar PV array feeding the grid than why do we require a DC link capacitor? A MPPT technique will ensure that maximum power and required reference voltage is made available at inverter terminals.Why is an energy saving device required at the inverter input terminals? Is it working as a filter? Is it that the PV array will transfer its entire energy to DC link capacitor which will further transfer it to the grid? If yes, why can't it be done without capacitor?
In steady state do we need to use DC link capacitor or is it just required for dynamic conditions?
Hi everyone,
I am doing research on small signal stability/ dynamic stability in a microgrid. As you know, it's the droop parameters of power controller which are mainly responsible for the dynamic stability of a microgrid. I am thus, considering research on optimization of these parameters. I have however few questions regarding it.
1) The load modeling plays a vital role in small signal stability of a large grid. However, I have seen most microgrid loads are represented as only impedance (R-L load). Can I expect a much different behavior if I model the load also as constant power or constant current type?
2) The dc side voltage is considered constant in most microgrid analysis. If I model the PV or some source, the dc reference changes. Do you think this may effect the dynamic stability?
3) Thirdly, are there any specific suggestions in dynamic stability domain of a microgrid which I can use in my research?
Thank you in advance
As we know, coherent groups of synchronous generators can be identified and converted to an equivalent dynamic model to simplify a given power system and still maintain the dynamics of the system. However, the Type-3 and Type-4 wind farms do not possess much inertia and hence cannot replicate the behaviour of synchronous generators. What approaches can still be made to aggregate the wind farms present in a region and connect it to a single transmission bus, such that the dynamics of the system is still maintained? Any help on this would be much appreciated.
Hi,
I am trying to model a system in PSS/e for transient stability studies. The network I am trying to model has a total demand of 1300 MW during peak season and it is interconnected to two other countries which have total capacity of 10 GW and 2 GW. I've short circuit MVA for the two interconnections, using which I've calculated the Zsource of the machines.
I've two questions:
1. Would I be using the short circuit MVA to represent the machine base or total capacity of the each machine for the studies?
2. Which generator and governor model to use to represent the inter-connection? Also, what would be the inertia (H) of the machine for transient stability studies?
Thanks for the help.
which one is the most worst harmonics for power system from the following harmonics
(3rd, 5th, 7th and 9th)
and why?
Could anyone kindly provide me a basic level of research paper which gives me an idea of how to integrate a battery or storage system in a simple series APF or in a STATCOM using the Simulink model?
Im trying to model a SVC in Etap to replace normal capacitor bank. But when I run load flow simulation, no MVAR is injected from the SVC, as how a normal capbank would do. Can anyone advise me on this?
Thank you in advance
what is the technique by means of which we can inject harmonics in a system?
Hello everyone,
I am working on analysis of PV Solar penetration on power system stability. I want to know about what probability distribution function does the Solar forecast error follow? The time interval of interest for me is 1 hour.
Cheers
Sam
Dear all,
Generally, when we talk about the large scale of PV penetration in power grid, we associate the term stability. But, in case of roof top PV system to be connected extensively in the LOW VOLTAGE radial feeder, what are the factors to be focused on? Voltage Parameter violation, energy loss tracking, etc being the ones i pointed out. Others? We don't have to watch out for transient stability issues, do we?
Thanks in Advance.
Hi
i know this question is basic but it confusing me
can someone explain to me the example 12.9 from the book of power system stability and control of prof KUNDUR.
1-I did not understand how he found the critical modes of interarea oscillation, after he calculated the frequency there is more then mode how he chose the critical one ?
2-when we have some modes (eigenvalue) has frequencies in the range of 0.7 to 2 HZ ,it means local interaction how we can eliminate this local interaction (i found in the book of prof Kundur talking about using the right eigenvector) how we can use it
to delete this local oscillation
i really need your help
thank you
I have a problem in my simulation in MATLAB. There is a error in compensation block. Can anybody to help me?
I've attached my simulation (simulink file) and Circuit topology (Word file) In the following. Please check it.
Why do some use alpha-beta transformation while others use dq0 transformation? Can anyone explain (if its because of my lack of understanding of both transformation applications)?
I am working to implement an Extended Kalman Filter to estimate the dynamic state of a synchronous generator connected to a Power System. I am using Power World Software to generate simulation data to use it as input to the estimator, and I am adding gaussian white noise to the data as "measurement noise".
Can someone tell me how can I add "process noise" to this simulation data?
I have two Power Quality meters (UniPower UP-2210 and CT Labs Vector II) on a 8.5 MVA 66kV 50 Hz network, connected at the same points on the same Instrument Transformers BUT don't give out the same measurements (Powers and Power Factor).
These instruments were installed by their manufacturers and are all well calibrated.
What should I probably look to solve the issue??
Hi everyone,
I am trying to create some simple user defined models (UDM) in psat. I am using psat 2.1.9 and tried to create UDM from component browser in PSAT GUI. However, I am unable to define anything like buse or state variable on a new model. I then tried to modify the existing examples and still was unable to do it.
Can anyone help me with it?
Cheers
Sam
This paper includes area detection, sector selection, voltage vector selection of NPC inverter to limit hysteresis current.
For a system
dp/dt=Ap+f(p,t), (1)
where f(p,t)<=0 for any p in the domain and t. If dp/dt=Ap is asymptotically stable of zero solution, is the system (1) same with dp/dt=Ap near the zero solution?
Hi everyone,
I am analyzing the effect of PV penetration in small signal stability. My test system is the two area system from Kundur book shown in file 1. The PV controller is as shown in the file 2. It only has an ac voltage regulating loop which consists of a PI controller.
I then tested the system. For a fixed PV generation (700MW in this case), when I change the integral gain (Ki), I found out that the inter area damping decreases! The initial gain of Ki is 50 where the corresponding inter area damping was 2% but when I reduce it to around 15, it reduces to around 0.8% as can be seen from file 3.
I am a little bit confused. Does this result mean that he PV integral controller can affect the interarea electro-mechanical mode of oscillation?
Cheers
Hi,
I am looking to design a robust power oscillation damper for a large power system network. As you know, I will have to obtain the information like eigen values etc for which I could use a software . My question is their any software which allows to design my own robust controller and later on implement with the test system and still obtain the crucial information like eigen values and time domain simulations?
Thank you in advance
What are the conditions, we should check, while selecting exciter and/or power system stabilizer for different type of generators (like GENROU) for transient analysis.
Can anyone please tell me which exciter and power system stabilizer is more suitable for generator like GENROU and/or GENSAL.
Hi everyone,
I plan to modify some renewable energy converter structure (say PV and wind) and study their effect on low frequency oscillations in the grid. Once, I modify, I want to connect it to a grid or a large number of buses. My queries are:
1) I'm aware that most commercial and free software have their own built in models and can give information about eigen values. Is their some way so that I can similar information for my modified model?
2) How does our fellow authors test say a new robust controller that they built in a large IEEE bus system?
Thank you in advance
The placing of DG units in IEEE RTS - 96 System will improve the reliability?
Am trying to refine my Finite Element Analysis to take into account of the small gaps that must exist between the magnets and the rotor slots that host them, in order to be phisically able to insert the PMs in the slot.
These small gaps will provide for some marginal reduction of the magneto-motive-force produced by the magnets.
I want to capture this effect without being forced to have a very fine mesh in such gaps, so I'd like to model the PMs as completely filling the slot while properly modifying their properties (coercitivity and permeability) in MagNet, obviously achieving the same result of flux distribution in the machine as achieved with the real, "gapped" structure yet in a more computationally efficient way.
Has anyone developed a method to do this?
Thanks a lot,
Francesco
the bode plot response of a power system stabilizer, the phase is always above the 0 degree, how to calculate the gain margin?
Regards

Utilities normally charge a penalty to customers who have a power factor below certain limit, which is typically between 0.90 and 0.95. Power factor limits applied in some countries are for instance: Venezuela 0.90; Chile 0.93; Colombia 0.90; Uruguay 0.92; Argentina 0.85; Spain 0.95; Ecuador 0.92; etc. The penalization scheme also varies from one country to other, ore from one utility to other. I would really appreciate your comments on how this limit should be defined, why one country use 0.90 and other 0.93? which aspects must one have into account for defining this limit and the penalization scheme?
Hi all,
I am trying to analyze a rural microgrid. The microgrid is powered by Microhydro. This microgrid contains 7 synchronous generators which are interconnected through transmission lines. As far as I know, they have diode based excitation system. The size of the generators is very small (maximum=16kVA). My question is:
1) Can there exist local and inter area mode of oscillation between the generators as in the large grid?
These Microhydro generators uses a fast power electronic based component called as Load controller which is responsible for the frequency regulation. As the standard software doesn't have this load controller,
2) Can I approximate this load controller with a governor of large gain for the simulation?
Thanks in advance
Basically, I want to find out the generator coherency employing the slow inter-area modes information available to us.
How can we correct the power factor of two switch non-inverting buck-boost converter? because in boost mode it is easily corrected but in buck mode input current is discontinuous ?
the parameters of PSS application in automatic voltage regulator are adjusted by conventional trial and error method. is there any other accurate scheme to achieve the gains for optimum performance.
I recently came across the seminal work on "Negative-sequence current injection for fast islanding detection of a distributed resource unit". The paper says "The RLC load tank draws the rated, positive-sequence fundamental current component supplied by VSC at unity power factor. If a 60 Hz negative-sequence current component is also injected by the converter current controller, it flows into the grid through the low-impedance path provided by the stiff utility grid".
Why does the grid have a relatively larger positive sequence impedance than the negative sequence impedance? (Since the load draws positive sequence current and not the negative sequence current, even though the positive and negative sequence impedances are the same for the static RLC load)
Thanks,
Mayank
factors that could cause power system failure, system failure probability caused by uncertainty in component reliability parameters
Which factor is most severe for power system collapse? Whether it is under frequency or under voltage?
I am highly interested in powers system protection and stability can anyone help me with a researchable topic for masters degree theses.And how tips on how to get started?
could anyone please tell me as to why there is distortion in the supply before a bridge rectifier circuit with no load connected at its terminals?
i have worked on design of PSS for SMIB and multimachine system.
At present my task, design hardware of PSS in power plants.
plz provide best suggestion to solve above problem.
For example: type of the load, regulation of GOV, AVR, PSS and ..... .
What is important to a long term voltage stability in a 30 bus IEEE?
From the basic engineering itself this question has posed me lot of trouble. The main reason is that there is lot of explanation available and few contradict each other. For example, one explanation was it is the medium through active power is transferred, if that is the case then what about DC power transfer?
So here i would like to know your opinion on the concept of reactive power and would like to discuss each and every view so that i can have a clear cut understanding of 'real REACTIVE POWER'.
Does anybody know how can I get WSCC system disturbance data on August 10, 1996? I have tried to access this ( ftp.bpa.gov/pub/WAMS%20Information/ ) , but it seems does not work as well.
Rotor angle stability and voltage ratings are somewhat interlinked but rotor angle is purely on the generation side, so what effects can it cause on voltage stability limits?
I understand that when the current reaches zero,the voltage across phase to earth capacitance is maximum which tends to restrike the arc.After that I was unable to follow.I attached the document I read from.Thanks in advance
just a short question. As I am working with Power Factory 14.1/ DIgSILENT i have to write a small skript to get my program doing, what i want it to do.
The language used by Power Factory is called DPL. I want to create a new Matrix, in witch i will write the results of a load flow analysis later on. To create such a matrix the manual gives the following example:
M1.Init(x,y);
With x and y defining the rows and collums of that Matrix, and M1 beeing the name of it. If i want to create a Matrix like that, i get the messange, that M1 is not known and thus the program stops.
How can i tell Power Factory, that i would like to create a new matrix?
Thanks for every answer.
Hello,
Dear RG researchers, as I am working on a paper I need a PSCAD-model of the IEEE 39-bus system. I would be really grateful if anybody can help me with this.
Regards,
Akbar Amirian.
Loads, generators, line, governor and PSS data for 10 generator system. Thanks in advance for your replies.
For damping of oscillations using PSS4B which parameters are most preferable as it contains 33 parameters if we observe the block diagram of PSS4B.
As PSS2B contains Kst(gain) and Time constants T1,T2,T3 and T4.
I want to tune a power system stabilizer for power system stability in single machine and multi-machine power system, i need to an idea that how can I use RL in this process,
My research area is handling optimal reactive power dispatch problem with voltage stability in transmission/distribution/microgrid. Is it good? Can you suggest?