- George Zheng Chen added an answer:1Vanadium redox flow batteries:Overpotentials increase near membrane?
I am simulating a case of vanadium redox flow batteries with carbon felts of thickness3.8mm at 50 percent SOC.Now I am getting an overpotential across the thickness of negative electrode which increases near the membrane.Can anyone explain why this scenario happens?
I guess by using the word overpotential, you actually were modelling the distribution of potential crossing the cell. There should be potential changes near the membrane, reflecting the kinetic barrier for ions to enter/exist the membrane. These kinetic barriers in relation with ionic charge transfer are not the same as, but add to the usual/physical resistance.Following
- Adrien Letellier added an answer:6How to start PMSM motor in sensorless control technique ?
I am simulating sensorless control of PMSM. I am giving constant theta at the starting time but my motor is not starting, what could be possible reasons?
If it is just to start the motor before estimating the control variable with your algorithm, you can use scalar control (V/f = cst).
It is not optimal but it should get your motor starting, also I recommend to add a dead-time compensation.
- Kishor Babu Gunti added an answer:6What is wrong with my current waveform?
This question pertains to Matlab simulation. I will be grateful in case anyone knows the answer.
Attached .docx file is a Simulink circuit of a inverter simulation. In order to implement close loop control of inverter, I first make it work as rectifier and trying to do its PLL and current control loop implementation. In this quest, I am applying a voltage through a grid and modify it to another level by transformer. I am not able to figure out that after putting any Kp and Ki values, why does the input current waveform shape is not symmetrical? Can any one help me to find the problem? In another file, I have attached Voltage (Upper) and current (Down) waveform taken from grid. The corresponding scope is marked in .docx file.
you can apply a voltage source from grid and pass through zero-crossing detectorFollowing
- Saran Satsangi added an answer:3Does anybody know of a PowerFactory (*.pfd, UCTE,...) to OpenDSS converter/script/... ?
For a industry research project we can get distribution grid models which they have modeled in PowerFactory. We would like to work with the models in OpenDSS and Matlab and of course would like to spare remodeling the grids in the software. I can't find anything online to achieve this.
Has anybody achieved exporting from PowerFactory to OpenDSS? Maybe even a self written script to achieve this which he/she is willing to share?
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/Following
- Rajanivedha Ramakrishnan added an answer:4Explanation on the model of REGC-A and REEC-B model in the power world simulator?
can some one help me lending hands to under the blocks which means the operation of the control system model of generators and exciters. I am in need of urgent help
I need to know the operation of the block diagram of these blocks and how it is helpful in integrating it to a pv systemFollowing
- Fatemeh Jafari Naeeni added an answer:1I am trying to catch the electrolyser, storage an compressor cost even from quote but for a bit large case and also if i move from size to bigger ?
I am trying to catch the electrolyser, storage and compressor cost even from quote but for a bit large case and also if I move from size to bigger size how I can scale the cost based on the big size?
maybe i can help you but need more explanation what you want exactly!Following
- Gbenga Odukale added an answer:35How can two renewable energy sources interconnected?Eg. A solar array and a wind turbine are to be interconnected... Can they be connected directly in parallel or does some special arrangement have to be made while connecting them... Can both the sources work simultaneously?
On May 10, 2016, I added a contribution to this thread. This new contribution has been made necessary by a state of sincerity. As far as the information in the paragraphs of the previous contributions were concerned, they referenced events which we all knew existed in the past except for the fifth paragraph, which was an attempt to provide a solution the thread's question.
It is true that this previous contribution might have been a bit blunt about evolving challenging changes, but I recently found out that the solution I provided through this previous contribution took for granted the state of sincerity, that is, the state of real-life considerations.
Since one and a half month ago, I started assembling the first commercial version of the Battery-Powered Generator I co-innovated and unlike the prototype, it is to have DC voltage inputs from battery, solar panel, wind system and external/internal battery-chargers. It was in trying to build a coupler system for these different DC voltage inputs that it became clear the coupler will include some form of passive logics, not just only diodes. I evetually built it, but it became a proprietary design.
I am apologizing to all who had viewed and read my previous contribution in respect of the following statement from the fifth paragraph,"...A simple coupler is a system of diodes and nothing more..." for having expressed a view that was an oversight of real-life scenario.
- Mauricio Neiff added an answer:4How to calculate the DC capacitors for a 5-level diode-clamped inverter?
Hello everyone. I'm designing a 5-level diode-clamped inverter and I have met the following issue: as time passes (0 to 0.5 second simulation) I find a crossover distortion in the output sine wave (filtered) that can be mitigated by increasing the DC capacitors (those which divide the Vdc input into Vdc/2).
To prove this, I have simulated the inverter replacing these capacitors with ideal DC sources (Vdc/2 rated each one) and the crossover distortion dissapears.
As far as I understand, this means that I should have large capacitors in my real circuit, the question is: how to calculate them analytically?
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.
My advice: Don't trust much those "multilevel inverter topologies with reduced swiches", they hide several drawbacks.
Thank you for your cooperation!Following
- Hauke Gravenkamp added an answer:8MATLAB m file runs an error, what happened?
First, all the input variables of function are in the workspace. Then, I enter the function in the command window like this and I can get the results:
However, directly running in the m file , that will cause a fault:
So, what's wrong and how can I run the m file correctly?Following
- Ajitesh Panigrahi added an answer:3I am working on Unit Commitment problem, I need data for 20 or more generating units with load profile can any one please provide?
I am Working on Unit Commitment, can any one provide test cases for 20 or more thermal generating units.I dont want to replicate units.
It is better to consider local system operators while testing for unit commitment and dispatch scheduling. Please consult with your local electrical generating authorities and simulate their actual case models. An alternative is already suggested by Jeremy.Following
- Gautham Ashokkumar added an answer:8How can I calculate the voltage sensitivity of buses in a radial distribution network (sensitivity to reactive power changes) using simulation tools?
Is there a way to use available power system simulation tools to calculate the most sensitive buses (in relation to voltage)?
I'm using a scaled version of IEEE 34 bus system and I need this info to decide on which buses and phases to inject reactive power to control the voltage.
@Debasish: can you explain a little further or provide any sources?
I also have loads modeled as variable R-L loads., plus they are all unbalanced loads in IEEE 34 which has to be accounted while finding voltage sensitivities.Following
- Sergio Rivera added an answer:14How can I find the IEEE-118 bus system data?I am working on an economic dispatch problem considering environmental issues and want to apply a new meta-heuristic algorithm to solve this problem. I need this system data. I don`t have access to this system the B-loss coefficients. I have a B-loss coefficients matrix, but its size is 54 and in this system in papers there is just 14 units. Any advice? Can anyone send me this matrix?
- Mahamad Nabab Alam added an answer:2Is it possible to develop models within Simulink (without using Matlab code) for load flow calculation, load forecasting and optimal power flow?
For our project, we need to explore the possibility of developing functional blocks for load flow, load forecasting, optimal power flow, etc. in Simulink, without using Matlab code so that the functions can be easily converted as function blocks to hardware using other software. Is it feasible?
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.Following
- Ihor Shelevytsky added an answer:3How to measure Pulse width at receiver?
I am not electrical engineering student but currently I am looking to measure the pulse width( in fs) of received signal. Given pulse width 10^-13 s, with power level let 1Watt of transmitted pulse, when this pulse is transmitted on channel it is distorted by noise model N, and weakened by attenuation A.
what will be the pulse width of received signal. I can analytically solve it for received signal power/energy distribution (pdf of received signal energy) but I can not calculate the actual received pulse and its pulse width.
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 OscilloscopeFollowing
- Julian Freytes added an answer:9Which software is best for drawing Power Electronics circuit diagrams for good quality research journals?
I currently use MS visio for drawing Power Electronics circuits and looking for a better one. Any one who can guide me, Please.
Check IPE drawing, free very easy and with integrated LaTeX inside.
- Kandasamy Muthukumar added an answer:4Why is resistance of a transmission line negligible and the resistance of a distribution system is considered to be predominant?Can anyone address this question?
can any one tell me the typical value of r/x ratio of distribution lines and high voltage transmission linesFollowing
- Debasish Mondal added an answer:19Any advice on optimal location of facts and DG?
if i have solve optimal power flow problem for following function
1. fuel cost
2. active power loss minimization
3. reactive power loss
4. voltage deviation minimization
how to find out where optimal location of DG-TCSC-SVC-UPFC-IPFC-STATCOM-DSTATCOM
and which case improvement when find its optimal location
You may follow this Article you will get about optimal location of FACTS device.
D. Mondal, A. Chakrabarti and A. Sengupta, “Optimal placement and parameter setting of SVC and TCSC using PSO to mitigate small signal stability problem,” International Journal of Electric Power and Energy System, vol. 42, no. 1, pp. 334-340, April 2012,Following
- Karar Mahmoud added an answer:12Does anybody know Matlab codes for optimal placement and sizing of DG ?.
This paper contains simple analytical formulations for the DG allocation. It is very easy task to implement it using matlab.
- Aravindkumar Yelashetty added an answer:1Any good/reliable laser company for getting a 690 nm CW laser diode with >1W for doing second harmonic generation?
I just would like to know if you could recommend me any good laser company for purchasing for this CW 690 nm laser diode with >1W output power I am interested in.
I will develop 345 nm CW laser generation from 690 nm laser diode. if you have similar work experience about diode harmonics, could you give some advice or recommend some references.
the type of the 690 nm laser diode? I choose FP or VECSEL.?
I would be very grateful if by your experience you know of a good one you could recommend me.
click on the link it may helps you
- Michael Meisser added an answer:4How can we correct the power factor of two switch non-inverting buck-boost converter?
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 LC-filter will only smooth the high-frequency current ripple caused by the discontinuous current input of the buck/boost. However, the control of the DCDC needs to follow the desired sinusoidal voltage shape in order to lead to a sinusoidal current at the input. Be aware that the LC-filter may add some difficulties in ensuring control loop stability since it becomes a part of the control loop.Following
- Pouya Salyani added an answer:4Which type of conductors must use in 123 bus test system ?
hello. I want to use 123 node test system for switch placement. Can anyone help me about the types of conductors to use? its given data or other ones? because it is imbalance and i want to implement in balance condition.
- Robert Fischer added an answer:5Is it possible to estimate irradiation / cell temperatures in every location of 10km x 2km area?
This is a real world problem:
There is a PV plant which covers 10km x 2km. In the center of the plant, there is a weather station, which measures GHI / POA irradiations and reference cell temperature.
I am going to simulate a PV cell model for each string in the plant. As we can see, only weather station data are available.
Thus, is it possible to estimate irradiation / cell temperatures in every location of 10km x 2km area based on the weather station measurements?
There are companies which can provide 15m x 15m resolution irradiation / cell temperature, how can they achieve it ?
Hi Bruno, you write it is a real world problem, but what is the real research question? What problem do you want to solve? Partial (and moving) cloud cover causes performance differences in the strings, I understand, but I doubt that temperature changes (inertia!) through e.g. moving clouds may have a significant impact on performance - please explain, I would like to know and learn if my assumptions are wrong. thanks, RobertFollowing
- Anand Mp added an answer:3Real measure high resolution solar data (15 mins - 30 mins) for Canada?
I need high resolution say, a measurement interval of 15 mins - 30 mins solar radiation data for my research. Most of the hourly data archives have average hourly solar radiation which don't accommodate the variation in horizontal direct beam radiation (looks like a smooth deterministic curve). I need to see the deviations in radiation due to cloud and other obstructions if any.
Please comments your suggestions. Thanks in advance!
Thanks a lot. This is wat I was looking for. As my ongoing research is case specific (Manitoba system) I may have to get a similar data for Manitoba. Anyway, these set of data will serve the purpose now.
- Abdulrahman Dahash added an answer:5Can anyone help me with some distribution grid modelling on Simulink?I need it for my masters Thesis.
For Dymola, you can check Buildings Lib. It's an open source library. By using this library, the models in this library can also be coupled to other simulation softwares.
Hope that helps!
- Sergio Honwana added an answer:6Who can help to find IEEE test system of Radial low-voltage unbalanced distribution system as detailed model (R & X of lines & loads)?
I need to valid test system of Radial low-voltage unbalanced distribution system. Each one of the Lines & loads in this system is an impedance (as R & X ).In this test system, the real & reactive power can be defined or not.The important cases at the required test system are:
1-Radial Distribution system
3-unbalanced in load side
4-Impedance values of lines & loads
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...
- Srete Nikolovski added an answer:2How can I model the two in-line voltage regulators in IEEE 34 node distribution test bed in PSCAD?
There are two 'in-line voltage regulators' as specified in the test feeder data (Attached), between nodes 814 and 850, and between nodes 832 and 852.
We have the IEEE 34 node system already built in PSCAD with loads.
What are these "in-line voltage regulators"? Are there built-in components in PSCAD or how else should they be modeled?
Dear Gautham Ashokkumar
I am not familiar with PSCAD , since we use European DIgSILENT softwere which can model all components mentioned by prof Sanjay in his answer. You can us SVC or Series compensation to regulate voltage of the line or DVC.
- Tony Castillo Calzadilla added an answer:5Can anyone help me with the battery charge?
Hi my friends I need to regulate and control efficiently the battery charge with the output voltage and current than flow from the buck converter, can anyone give me some ideas in order to improve it?.
I'm work in in Simscape SimpowerSystem of simulink and my system need 1000 A, i think a BJT transistor is no enough, what do you think?Following
- Inam Bari added an answer:32Which is the latest Optimization technique for Power system problem solving?My project work is optimization in power system (like load flow, parameters and position finding, filter designing, fault location etc ) and I have used PSO (particle swarm optimization), different new improved version of PSO, HS (harmony search), and different new improved version of HS but I want a new technique, which will gives best results in comparison to all other existing Optimization technique. Please can anyone suggest a new technique which will give best result in comparison to other technique?
you can use evolutionary algorithm EA or Estimation of distribution algorithm (EDA).Following
- Srete Nikolovski added an answer:5Thermal rating of cables, temperature computation around the media?
Does anyone know and can sent me a link for free software which can be used for thermal analysis of cable - ampacity and temperature computation around the cables in different environment (ground, water, air, concrete pipe.) I know that there are many commercial software from CDEGS, EATON-CYME..... but I need easy free software to eliminate manual computation.
Thanks in advance
Super, valja ga proučiti !!
U svakom slučaju veliko hvala.