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I'm looking for help in COMSOL Multiphysics modeling of VRFB for integrating with grid using Livelink in MATLAB Simulink environment.
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Where can I get modern LVRT/HVRT Grid codes ?
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For LVRT you could have a look at the European RfG https://www.entsoe.eu/network_codes/rfg/
Unfortunately the HVRT requierments are not yet reflected in this document.
For HVRT you could use the German or Italian HV or MV grid code. For Germany you could find it here https://www.vde.com/en/fnn/topics/technical-connection-rules/tar-for-high-voltage
But it's not free.
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Generic schematic is shown below for understanding.
Answer to the aforesaid question is requested from the experts, while considering the power flow equation i.e P = [Vs*Vr*Sin(theeta)]/X
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Markus Pöller Thank you Markus. Current loops are there to limit current through the converter. is there any role played by this current loop in synchronizing the DSTATCOM at PCC?
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What parameters should be metered?
What are the other considerations?
Remote monitoring?
Relevant sensors?
Relevant mathematical tools?
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What should be the multidimensional nature of EV charging station in urban and rural areas?
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For immediate infrastructure creation, all Fuel filling stations should also have EV charging stations.
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Kindly suggest some upcoming research areas/ challenges to explore in (but not limited to) sustainable planning, and performance assessment of hybrid renewable grids.
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These investigations can provide you with a very comprehensive overview.
  • A hybrid renewable energy system for a North American off-grid community
  • Optimization of PV-biomass-diesel and grid base hybrid energy systems for rural electrification by using HOMER
  • Optimal design and techno-economic analysis of a solar-wind-biomass off-grid hybrid power system for remote rural electrification: A case study of west China
  • A thorough investigation on hybrid application of biomass gasifier and PV resources to meet energy needs for a northern rural off-grid region of Bangladesh: A potential solution to replicate in rural off-grid areas or not?
  • Heuristic indicators for the design of community off-grid electrification systems based on multiple renewable energies
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The sources are PV and Grid. Equations i am applying right now is (1) Savings($) = ImportTariff * (ACLoad - Grid Import Energy) + Export Energy * ExportTariff
The second Equation is (2) Savings($) = System fee - (ExportEnergy * ExportTariff + Import * ImportTariff ). System fee is daily/monthly/weekly charging fee for system maintenance installations.
Moreover in some systems there are installed battery systems. Any new insights/feedback on equations would be appreciated.
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Savings (Dollar) = [ Export Energy * ExportTariff ] + [ ImportTariff * (alternating current Load - Grid Import Energy) ]
Basic savings (Dollar) = ImportTariff * (alternating current Load - Grid Import Energy) + [ Export Energy * ExportTariff - System payment ]
! you can consider one parameter such as Z as any payment or extra cost of systems.
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As the penetration of grid-connected solar energy increases, is it technically possible to replace most of the conventional power generations including coal, gas and natural gas in modern power grid? Is there any critical technical challenges we need to overcome? There are various researches ongoing such as virtual inertial (VI)-based inverter, maximum power point tracking (MPPT) and hybrid energy storage system (ESS) to address voltage/frequency instability, IV & PV non-lineality and solar energy non-availability during night time respectively.
Plus, there are many technologies like artificial intelligence (AI), smart grid, blockchain and other advanced terminologies available for solar energy. From these perspectives, will the solar energy eventually replaces conventional power generation or it will be limited as a supplementary energy source for existing power system which is ideal for remote and vast area?
Welcome to exchange your valuable perspectives on the future of solar energy.
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Please see my road map for the transformation from conventional to PV generation in the paper at the link:
Best wishes
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I have tuned the PI controller for the voltage control loop and inner control loop. But the problem is that it is not stable from a wide variation in the load/bus voltage. On the DC bus, there is a boost converter connected which is used to transfer power from renewable generation.
While Tuning considering rated load (separate/isolated) the operation is good. But on connecting it with DC Bus (microgrid) it is not working properly.
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Maybe you would like to take a look at the following paper:
Codes to reproduce results are available and robust stable PI controllers were successfully tuned.
Best
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Is it possible to control the dq component of the three-phase grid-connected PV system using Proportional Resonant control?
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Yes, it is possible. All starts with what you want to control. For the best of my knowledge, in dq-frame we may want to control:
1. Fundamental component. In this case we just need a PI controller. The dq-frame rotates at the fundamental frequency.
2. Harmonic components. We have some options here.
(a) We can use PR tuned at 6th in order to compensate 5th and 7th. The dq-frame rotates at the fundamental frequency.
(b) We can tune PR at 5th and 7th. We need to have dq-frames rotating not at the fundamental frequency, but at -5th and +7th frequencies.
(c) we can use PR tuned at 5th and 7th and make the dq-frame rotates at -6th and +6th frequencies.
3. Oscillation compensation. There is also an option to compensate double-frequency oscillation that arises in dq-frame due to unbalanced grid voltage conditions. In this case, a notch filter is used, which similar to the resonant part of the PR controller. The notch filter is tuned at 2sd harmonic.
One good book that covers these issues is the Grid Converters for Photovoltaic and Wind Power Systems by Remus Teodorescu, Marco Liserre and Pedro Rodriguez.
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Dear all,
My question is regarding the synchronous reference frame phase-locked loop (SRF-PLL), as discussed in the book "Doubly fed induction machines:Modelling and control for wind energy applications". The output of the integrator is taken to be the estimated value of the voltage space vector angle. In simulation, the default value of an integrator is zero; this means that the initial phase angle of the voltage space vector is always estimated to be zero, which may not be true. Does this mean that there is a deficiency with this kind of SRF-PLL? Otherwise, how should the estimator block be modified?
Kind regards
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Yes, it is possible to do, but you need to clearly understand dq algebra and trigonometry. For a given initial torque and flux in the machine, you back-calculate what would be the dq set points, by assuming then you find the initial values for sine and cosine, get the trigonometric identity to calculate the initial possible values for the angle. It is algebra + physics + electrical engineering, plus really know what you are doing.
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Hello everyone,
I have three questions about connecting onshore wind farms to substations:
1) I know, that larger onshore wind farms are connected to higher voltage levels (110 kV or 132 kV). But which voltage level would I choose, if I only have one wind turbine? does a rule of thumb exist depending of the wind turbine / farms capacity (MW)? A reference to cite would also be nice.
2) I have a wind farm which is already connected to a substation. Another wind farm is newly built and is nearer to the first wind farm than to the substation. Is it also possible to connect the wind farms, instead of the connecting line to the substation?
3) Do you have references for costs to connect wind farms to substations for UK? For example costs per km.
Thank you very much!
Jann
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There are many codes for integration of renewable energy into grids. Nevertheless, the codes hardly discuss the transient response of grid connected generators and converters to maintain a power balance (equal input power and out power) in the DC link that connects the RE source to the grid under transient conditions. This is especially vital under a fault. The fault codes mainly focus on the system performance in an interval of tens to hundreds of msecs. However, It seems that there are needs for codes to govern the first few msecs of the system performance after a fault to maintain the balance and prevent the DC link over-voltage or over-current.
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Thats y grid codes are protean
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I was wondering why Bipolar switching make less EMI comparing to Unipolar switching in SPTG-CPV inverters?
According to a below article, the EMI and leakage current is very low as voltage to ground VPE has no switching frequency component, while only the grid frequency component is present.(see attached picture)
Could anyone add more detailed explanation ?
- Does it mean the grid frequency component is not categorized as noise components so its presence is okay?
- Why does VPE has no switching frequency ?
[Reference]
A Review on Recent Advances and Future Trends of Transformerless Inverter Structures for Single-Phase Grid-ConnectedPhotovoltaic Systems by Kamran Zeb; Imran Khan; Waqar Uddin; Muhammad Adil Khan; P. Sathishkumar; Tiago Davi Curi Busarello; Iftikhar Ahmad; H. J. Kim
Energies, Vol 11, Iss 8, p 1968 (2018)
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Hi Nathalie,
working through pages 10 to 12 of the following paper seems to provide the answer to the question why VPE doesn't have a switching frequency component during bipolar switching:
I still did not complete the reading myself but by providing the link I intend to give you the chance to overtake my slow reading. ;-)
Hope this helps.
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I am looking for some methods to estimate the loads in a power system at a transmission level which can be lumped to the individual sub-transmission buses.
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OK. The subject belongs to the measurement based electromechanical equivalents. You will find sufficient literature including those (articles, conferences papers, and book chapters) authored by me and available within my RG profile.
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High-penetration of renewable power generation throughout the network might increase transmission/distribution congestion. What are the effective tools in both transmission and distribution level for managing congestion due to renewable penetration?
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Pena, I., Martinez-Anido, C. B., & Hodge, B. M. (2018). An extended IEEE 118-bus test system with high renewable penetration. IEEE Transactions on Power Systems, 33(1), 281-289.
Burchett, S. M., Chow, J., Kar, K., Zimmerman, R., Swider, M., Marwali, M., & Zhang, G. (2018, June). Investigation of Generator Ramp Rates in High Renewable Penetration Systems using an Academic New York Network Model. In 2018 IEEE International Conference on Probabilistic Methods Applied to Power Systems (PMAPS) (pp. 1-6). IEEE.
Schermeyer, H., Vergara, C., & Fichtner, W. (2018). Renewable energy curtailment: A case study on today's and tomorrow's congestion management. Energy Policy, 112, 427-436.
Zakeri, B., Price, J., Zeyringer, M., Keppo, I., Mathiesen, B. V., & Syri, S. (2018). The direct interconnection of the UK and Nordic power market–Impact on social welfare and renewable energy integration. Energy.
Thanks,
Sobhan
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Solar PV affect the system stability. It will exacerbate the situation when there is high penetration as well as when there is less penetration. How to measure the online parameter of the system so that we can calculate the affect of the penetration on the system stability?
What are the different ways we can counteract this problem?
Can forecasting of the data be a solution to the problem of stability?
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Unlike conventional generators (i.e. large thermal, and hydro), the dynamic properties of solar-PV (and wind as well as most of the new power generation technologies) are significantly different due to the characteristics of their components, electronic interface with the grid, inertia, operation mode ... etc. The following papers focus on the maximum penetration level (MPL) of solar-PV generators hosted by a grid. The small-signal stability, and FRT requirements are considered as constraints in the determination of the MPL. In addition, the impacts various modes of operation on the MPL are considered.
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Kindly help me with the parameter selection of the value of gains of the PR controller.
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Mathematically, the commonly used PR controller is not equivalent to PI controller. It can be deduced using the theory presented in the appendix of [1] that the controller in stationary frame shown in the attached figure is equivalent to a PI controller in synchronous frame.
[1] D. N. Zmood; D. G. Holmes. "Stationary frame current regulation of PWM inverters with zero steady-state error," IEEE Transactions on Power Electronics, 2003, 18(3): 814 - 822.
You can find in the attached figure that there exist coupling terms between the alpha axis-controller and the beta-axis controller. The commonly used PR controller in stationary frame does't include such coupling terms. The coupling terms come from the controller itself, not from the plant. If completely decoupled controller is required, the coupling terms generated by the plant model (e.g. the typical R-L model) should also be included.
I have done some test in matlab/simulink some time ago that such a controller performs exactly the same with the PI controller in stationary frame, if the parameters Kp and Ki have the same values.
However, in practice, the performance difference between the commonly used PR controller and PI controller may not be so obvious.
In addition, I would like to recommend the an advanced resonant controller, i.e. the vector-proportional-integral (VPI) controller. Its expression is s(Kps+Ki)/(s^2+w^2). Its numerator could be used to cancel the pole of the R-L plant. VPI controller could eliminate undesired peaks in the bode plot. According to my experience, it performs really better than the common PR controller. More information about the VPI controller could be found in [2] and other literature.
[2] Alejandro G. Yepes; Francisco D. Freijedo; Jesús Doval-Gandoy; Óscar López; Jano Malvar; Pablo Fernandez-Comesaña. " Effects of Discretization Methods on the Performance of ResonantControllers," IEEE Transactions on Power Electronics, 2010, 25(7): 1692 - 1712.
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I am trying (1- Grid Import/Load Consumed)*100
the other way could be Load consumed - grid Import that would be battery consumed. so i could then draw a graph between grid import and consumed from battery. Please clarify.
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China is building UHV transmission lines that supposedly will expedite renewable energy adoption by efficiently sending electricity from low population, high renewable potential areas to high population, low renewable potential areas. The US has a similar problem with renewable energy resources being in low population density areas. My question is:
How likely is it that UHV transmission lines will be built in America?
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No, it is not essentially required. In addition, transmitting power over large distances may cause many operational problems. You may read the following
A more practical solution that also can contribute in reducing the adverse impacts of the intense variability of wind power is the conversion of wind power to hydrogen, then transferring it to the design locations via pipelines. The hydrogen may be used in fueling thermal loads, or may be converted to electricity in either an electrochemical process, or a thermal process. You may read
Chapter 1 to 3 in
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I just have a basic doubt regarding how the limits of various PI controllers used for the design of current control technique of the grid connected VSI is being selected.
I feel that applying limits to the PI controllers is a critical aspect, but I am not sure how the values is to be kept for simulation (I have attached the paper titled "Single- and Two-Stage Inverter-Based Grid-Connected Photo voltaic Power Plants With Ride-Through Capability Under Grid Faults" kindly refer to Fig. 4 of the paper and the line highlighted in green.)
Also find attached the snapshot of the Simulink model made by me in the page-2 of the second attachment titled "pid_simulink_limit"
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Sanjoy Roy
What you propose is what is typically done nowadays, and for simple systems it works, skilled people do it even without simulation.
But if 5 parameters, P, I, D, low pass in D and saturation have to be chosen, there is a big chance that trial and error does not converge to the right solution. If there are resonances in filters or a DC-link with small film capacitors that add to the problem, the chances to find a solution by trial and error get very low. In practice also noise, disturbances and non-linearities can be present.
A typical non-linearity is the saturation of a controller (wind-up) but also that a control jumps from 95% duty to 100% duty ratio.
The Nyquist (or Bode) is an independent way to know if one is far away or not from what could be obtained.
My experience is that even a lot of systems get unstable at half of the switching frequency rather than the resonance frequencies.
A typical problem is that Matlab implements PWM without delay, which is true for a pure analog PWM. Most of people use that model for a digital system where there is definitely a delay between sampling and PWM compare levels.
In drives, the wind-up is eliminated by resetting the speed integrator when the torque is limiting during acceleration. If this is not done a lot of error is cumulated and will result in a big overshoot in speed.
Wind-up is one aspect, but there are many reasons why simulations do not correspond to the reality.
In theory the practice is equal to the theory, however, in practice it is not.
Alex
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Hi, I am working on PV system grid integration, for connecting the PV ssytem to teh grid through DSP, how to synchonize. I am using the TMS3200f28835 DSP kit, we are taking the grid voltage as a reference for syncronization
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You should should measure the grid voltage (point of common coupling) using voltage sensors. Then, you should design a phase locked loop (PLL) to obtain the grid voltage angle.Using this angle you can apply the voltage oriented control and achieve the synchronization with the grid.
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i need an example of xml file of a grid computing security policy or cloud computing security policy to analyse it where can i find and example , or how can i generate it ?
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Hi Sara
Sorry for the delay in getting back to you. The last couple of weeks have been somewhat fraught.
Anyway, my interest lies in all aspects of cloud, whatever the flavour. My initial focus was on key management issues, followed by technical vulnerabilities and forensic issues, which can be problematic. I have tagged IoT into the mix along the way, and will then move on to the the Threat Environment itself. By tackling the problem from different angles, my hope is that a better all round solution can be found. And there remain other issues yet to be properly addressed. This might take some time. Often, companies do not exactly help themselves as much as they could. It will be some time before all the holes can be properly identified, and properly mitigated.
Regards
Bob
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 I have a grid of flow velocity measures, and the topographic survey of the cross section. I am trying to interpolate with matlab, but results are not satisfying. I have problems to delimit the cross section area within which to interpolate. Moreover, I don't know how to account for the velocity at the wetted perimeter...
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Yes, SURFER: you could ask to MM and HP.
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I run RegCM model and I have obtained NetcDF outputs.I want to interpolate 3D gridded data with bilinear method.Do you have any idea how I can do this using Matlab? 
Thanks in advance.
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maybe i can help you but need more explanation what you want exactly!
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actually for grid synch. process i want to implement these two methods. among these, for PLL i would like to go with [Vgrid TO V(alpha-beta) TO V(d-q). so can anyone explain the whole process thoroughly ?
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I would not recommend dq control on single-phase converters. You will loose "information" during transients. You may find relevant information and references on this paper:
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My aim is to map PV plant locations to their respective transmission zones. 
NREL has approximately 6,000 simulated PV plants over US. These data were used for transmission grid integration studies. In order to perform any simulation, these PV plants must be mapped to their respective transmission zones (as the first step). However, I am having trouble finding the corresponding shapefiles.
Does anyone know where can I get the transmission zone maps (in any computer readable format) for any iso, such as CAISO, NYISO, PJM, etc. 
Just some clarifications: I understand that transmission line details are highly sensitive (which I do not need), but the zone maps (geographical boundaries) can be found easily on the internet. It is strange that the shapefiles are, in fact, hard to find.
Dazhi
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NREL has archived historical PV and wind output. Out of them, you can create your own shape files. If you have trouble getting those data, send an email to me; Jeremy.Lin@pjm.com
Best,
Jeremy
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The penetration of RE systems is increasing day by day. The implementation of net metering policies is encouraging the grid interconnection of RE systems at distribution level. But for weak distribution grids, is it possible to interconnect microgrids at single phase?
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Hello Mr. Joshi,
the first question you asked. I would answer with yes.
The second question is more complex. Connecting decentralized systems as microgrid being able to operate in grid connected and in island mode is possible but expensive. Therefore you will have a higher security of supply. It depends on what customers want.
Regards
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What are the significance of islanding in interconnected grid? How can it help to survive from grid collapse?
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Grid failure can occur due to a variety of causes such as: continued over-stressing, low frequency operation, increased load demand, peaking characteristics of the demand, ineffective load control, reduced level of security due to opening of interstate lines and violation of grid discipline. Separating healthy part in the system during fault at pre-determined points is called as islanding. To ensure supply of power, in a complex system, intentional islanding becomes necessary to save healthy part to recover from the blackout.
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How to ensure interoperability of converter stations from different manufacturers in DC Grid?
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Thanks for your valuable answers
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How integrating different MMC converter in the same DC grid from differents vendors ?
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Thanks for your valuable answers
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On connecting renewable energy sources (wind, PV etc) to electric power grids, it is necessary to estimate the grid angle at the point of common coupling so that power electronics converters can be provide decoupled control of active and reactive power. Several techniques are there to estimate the grid angle and frequency. These techniques are different in its speed of response, its accuracy, its ability to deal with harmonic distortion and mostly important their ability to support ride though operation during grid faults. The question is:
How can we establish a benchmark to assess and compare the performance of these different techniques ?
(to clarify the issue: For example in sensorless speed control of drives we can consider that a position and speed sensor can provide a benchmark data for assessing the accuracy of estimated position and speed)
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There are indeed many possibilities. However, the question is not what it should be but what you pay for.   In low voltage, if you reduce the rms in your own conductors you will need less power. But while using a PFC, you may introduce may be 3% loss and pay for it, it is probably more than the losses in your wires.
In industrial cases one pays for real power and reactive power, in the way the meters measure it, so by 15 minutes averaged.
In fact if you inject harmonic power into the grid, it reduces your energy bill, if you absorb harmonic power you pay for it, it is a shame...
I discussed the problem of harmonics in that paper:
In fact one rather should pay for the fundamental power, not for the total power you receive....
Also the power factor gets a strange definition when you look at how the electricity is tariffed...
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In general what is efficiency(in %) of high power grid integrated system.Suppose, I generate 50kW  from solar photovoltaic array and aim to transfer it to the grid using multilevel voltage source converters.How much losses are allowed in between?Is having efficiency in range of 90-95% acceptable?
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Actually there are two types of efficiiency calculated at PV grid connected system, the first one depend on the PV module efficiency, which range between 10 to 20 % for the best conditions. The second one depend on the converter and inverter used in the grid system, which arrange between 90 to 98 for both of them.
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this study is for rural India so kindly help me to find the reason and solution
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you can control the reactive power injected from PV in the control loops of the voltage source converter.
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Calculating dynamic pricing for energy (cost/kwh) for virtual power plant is my main focus now. The scenario is a system where the electricity market is liberalized and renewable energies (WT, Photovoltaic) are supplying a flexible load with a Gas Turbine (primary reserve).
Costs are sum of fixed, variable and operation cost. Finally the MCP is calculated according to how much energy the IPP will be generating the next half an hour. Thereby, I am calculating the Real Time Pricing every 30 minutes. But I have the following questions:
1. Solar doesn't produce power during nights, does the Solar IPP's make a loss during these periods? Or the calculation is already made excluding the non-solar hours for the project duration?
2. How does the producer make a profit/loss after unclear/bad forecasting (may be produces more than expected or ends up produces very less)?
3. What costs of  Gas Turbine includes when it is not producing any energy but acting as a primary reserve (reserve costs)?
A healthy discussion is always appreciated and suggestions are welcome. Thank you.
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Solar generator does not produce at night but it does not consume any energy. So if you neglect its depreciation, then at night it makes zero profit.
Since demand and supply should be balanced in any point in time, normally PV devices are embedded in network and production should be balanced with other sources (like hydro and thermal).
In liberalized energy markets there is hourly price that is calculated to balance demand and supply. Then the revenue of PV system should be the sum of its output in certain hour multiplied by the price during this hour. However, most of PV owners enjoy feed-in tariff (fixed price to sell to network) and this is a kind of subsidy. Without it PV system working in market conditions would be even less profitable.
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I need the software to prepare models for grid integration of small and large scale renewable energy systems, as well as other energy models
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Many thanks to all for your input and suggestions.
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Can a power generation  plant be directly connected to transmission lines instead of installing new lines to feed the S/S?
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All the above comments are relevant. Just to add more, before you add any generator to the system, you need to check the capacity of the lines, thermal limit, short circuit capacity and for control purposes, the damping limit is another important criteria. Another important aspect is that of protection. You cannot just connect a remote plant to your system without properly protecting your generator through relay protection and circuit breakers.  
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I designed a front end converter for my grid integrated solar pv system. Things are working fine but there are even harmonics in my current waveforms (Grid side). What can be the reason. 
Thank you
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Dear Tej,
We also faced same problem of even order harmonics.
they are mainly introduced because of the offsets in the sensor.
make sure that all the offsets given by the current sensors are removed properly.
you can try this small procedure
1. keep power reference to zero.
2. connect to grid.
3. check the current on the output of the inverter
 if it is not near to zero or having some offset then problem is surely because of sensor
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I am designing the decoupled form of control mechanism for VSC (Inverter) in grid connected solar PV. I am unable to find the proper method of designing the same. What should be the criteria we should consider for designing the same.
Please suggest me for the same.
Thanks
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Dear Akhilesh,
I recommend you study the following manuscripts. They may be helpful for your research especially the MATLAB codes and Simulink schematics.
Regards,
Morteza
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Normally, inverters with 110% of the rated power can produce as much as 46% of the reactive power. I am working on a grid connected PV system model with advanced inverter (VSI with SVPWM). Trying to model reactive current signal reference (Iqref) based on the grid voltage sag. 
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Dear Umid,
There was a European project, Meta-PV, that looked into the possibility of injecting reactive power for voltage control purposes. The outcome was that the proposed solution was not effective due to the high R/X value of low voltage cables. 
We are currently coordinating an FP7-project, INCREASE (www.project-increase.eu) where we are developing control strategies to use active power to do voltage control. The results already look promising. I will be presenting our project on the 2nd public workshop of the iGreengrid project in Paris this Thursday.
Best regards,
Bart 
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I have a grid data of shape (512, 512) and want to extract all the nearest pixels and their corresponding positions within some arcmin of a specific area of the data and regrid the small area using gaussian convolution.
This will help me to zoom that small area. Can someone show me how to do this in Python? Thanks in advance.
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Hi,
I'm not sure I fully understood what you're trying to do but the following code does the steps you've requested. You may however adapt some of them for your intended purpose. The code 1) creates a 512*512 array, 2) selects a bit of it, 3) rescales it to have more array elements, 4) Passes the gaussian filter over it, 5) and finally views all results (with matplotlib).
from __future__ import division
import numpy as np
import scipy.ndimage as im
import matplotlib.pyplot as plt
# 1) CREATING SOME TEST DATA
X = np.linspace(-5, 5,512)
Y = np.linspace(-5, 5,512)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X**2 + Y**2)
Z = np.sin(R)
# 2) SELECTING A BIT OF MY DATA
x0,x1 = 200,400 # X COORDINATES OF PARCEL
y0,y1 = 400,512 # Y COORDINATES OF PARCEL
Z2 = Z[x0:x1,y0:y1].copy() # CREATING TE PARCEL FROM COORDINATES
# 3) RESCALING THE BIT OF DATA
nx = int(1/((x1-x0)/512)) # APROX. NUMBER OF REPEATABLES FOR X
ny = int(1/((y1-y0)/512)) # APROX. NUMBER OF REPEATABLES FOR Y
Z3 = Z2.repeat(nx,axis=1).repeat(ny,axis=0) # BUILDING A RESCALE FOR Z2
# 4) PASSING A GAUSSIAN FILTER OVER IT.
Z4 = im.filters.gaussian_filter(Z3,3) # SIGMA 3 (PUT WHATEVER YOU WANT)
# VIEW ALL RESULTS
plt.imshow(Z.T,origin='lower',interpolation='nearest')
plt.title('Original')
plt.imshow(Z2.T,origin='lower',interpolation='nearest')
plt.title('Parcel')
plt.imshow(Z3.T,origin='lower',interpolation='nearest')
plt.title('Rescaled parcel')
plt.imshow(Z4.T,origin='lower',interpolation='nearest')
plt.title('Gaussian convoluted rescaled parcel')
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If possible, kindly tell me any link or book related to this. 
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One of the important features of the smart grid is the integration of renewable energy sources (such as wind and solar). Each micro-grid provides electricity to the customers as the combination of renewable and non-renewable energy sources. Therefore, the micro-grids first use the renewable energy produced by itself, and then, take remaining required energy from the main grid. Consequently, if there is any problem with the main grid, still, the micro-grids can provide electricity to the customers, and thus, supports the distributed architecture of the smart grid instead of the centralized one. Additionally, with the availability of renewable energy sources, micro-grids can provide electricity in a cost-effective and reliable manner.
There are several existing works related to the renewable energy and smart grid. Some of them address the following issues:
1. Dealing with the intermittent behavior of the renewable energy sources, while integrating it with the smart grid.
2. Impact of self-generated energy sources in the smart grid - load shifting, minimization of energy cost, providing uninterrupted energy service etc.
I would suggest to go through some papers related to integrating renewable energy sources in smart grid published in IEEE Trans. on Smart Grid.
You can also refer to the book entitled "Design of Smart Power Grid Renewable Energy Systems", Wiley Publication, 2011
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What are the best options to reduce voltage fluctuations, harmonics etc.
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See the TWENTIES project. It describes most of the issues, along with some exciting new solutions
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I"m using MATLAB/ SIMULINK to simulate the mathematical model of a wind turbine. The power output is 12 kw and the rated torque output is 440 Nm at 11m/s wind speed. I want to design a suitable Permanent Magnet Synchronous machine. I aim to interface the model with the grid. The wind turbine is a part of a Solar-Wind-Fuel Cell Hybrid system.
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This paper may be helpful
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The Grid involves almost 200 buses with 60 generators and over 200 lines
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I have prepared a Solar-Wind-Fuel cell hybrid system in MATLAB/SIMULINK and also interfaced the hybrid system with the grid as part of my final year project. I want to extend the work to transient behaviour and stability of the grid with the integration of the renewable energy sources and suggested power quality solutions.
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Generally the challenges will be in producing the output power with high quality and reliability to be synchronized with the local grid connection. Harmonics issue generated from inverters sometime need an extra equipments before connecting to grid. Power lossses during transmission before busbar connection point however not an issue due to infinite busbar will absorb the differences hence from commercial point of view, the local grid utility company somehow is absorbing the losses especially from solar side during night.
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I want to connect some PCs together and form a grid. Using Globus is one option. I would like to hear about other options and also, what are the challenges in this work and, if it has a bright future in India.
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OpenStack is one of the best available option for now....as it open source and freeware we can do all the type of R&D upon it. Its implementation is little bit hard but we can try to understand it .. here is the refrence link ...http://www.openstack.org/
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I want to know which is the best platform available to do this task. I have 2 PCs with linux os and I want to form a grid environment.
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Globus toolkit is widely used Grid middleware for implementing Grid computing concepts. You should visit http://www.globus.org/
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When we consider smart grids, what are the possible instabilities in the microgrid system?
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Could you please clarify, whether you want to know about instabilities in smart grids that occurs due to microgrids or instabilities in microgrids??? Although MGs are having lots of advantages, the higher penetration of MGs in a power grids can invite lots of instability issues...like voltage and frequency instabilities, low frequency power oscillations...etc. There is no well developed operational code for MGs. Independent control of MGs willtake the powergrids to instability, if MG penetration is more. In case of distributed generations (DGs), it can support grid stability with proper synchronous control.