Questions related to Relay
- Breaker interlock scheme
- Under-frequency relay (81) scheme
- Programmable logic controller-based load shedding
- Fast intelligent load shedding (ILS)
The above model is useful in studying and testing the distance relay when a fault occurs at 75% of the length of the line because the line is divided into four equal parts.
Cooperative communication (CC) can be explored to counter eavesdropping. Relaying and jamming are the sub techniques of (CC). However, Jamming is used to counter the strong eavesdroppers. Is there any other technique except Jamming to counter strong eavesdroppers in the network?
Our answer is a consistent YES. A qubit (or quantum bit) is today the quantum mechanical analogue of a classical bit. In classical computing the information is supposed to be encoded in bits, where each bit can have the value zero or one. In quantum computing the information is, then, also encoded in qubits.
This is inconsistent in (1), in a most basic point, because even classically, information is no longer understood to be encoded in bits. Years ago, this was true 50 years ago, but failed.
Today, one uses SystemVerilog with tri-state chips, as opposed to Shannon's theory with binary states, and two-state chips as relays.
Information is encoded in three logical states, in 0, 1,and Z, where Z is an open circuit standing for indeterminacy, with a coherent semantics for interconnects.
The qubit view is inconsistent in (2), another basic way, because one needs to move from the macroscopic, from a classical Boolean analogy of relays or switches, valid for the Law of the Excluded Middle (LEM). Then, in a formless and classical “fluid” model for particles, information was seen in the double-slit experiment as GF(2^m), and now must change to a more complex microscopic structure, with a quantum tri-state+, not qubit in two-state. The photon (e.g., a particle) is now modeled by an algebraic approach with ternary object symmetry, modeled by GF(3^n).
Comparatively, the current two-state quantum theory of qubits is linked, however, to the classical two-state “bit”, following Boolean or classical logic laws, such as the LEM, which carry only two possible values, “0” and “1”. This emulates the workings of a relay circuit, and uses the formless “fluid” analogy of classical information, that can only be blocked (relay open), routed or replicated (relay closed). However, information can also be encoded, in analogy to network encoding as announced in 2000, and not covered by Shannon's theory.
What is your qualified opinion?
In case, HRC fuse of motor protection in downstream takes more time to blow than the pick up time of Earth Fault relay, the incomer trips & interrupts whole plant auxiliry.
Normally, for a forward fault, phase difference between voltage and current of relay (theta) lies between -90 and +90; and for a reverse fault, theta is outside of this range. Some works, however, use negative components of voltage and current of relay to identify fault direction. I want to know that what is the criterion for a forward/reverse fault in this condition? In my simulation studies, phase difference between negative components of voltage and current lies between -90 and +90 for a reverse fault.
We know that the eavesdroppers are malicious nodes and they are not supposed to cooperate with the users. If we exploit opportunistic relaying protocol for the destination, can we consider the same protocol for the eavesdropper? If so, then how the CSI of the eavesdropper can be estimated at the relay?
Let us consider that we want to use a relay with an energy harvesting scheme. It has only a single antenna. Can the relay receive both information and energy signals through that single antenna? Consider that the information and energy signals are transmitted at different time slots.
Consider a dual-hop system where a single source tries to send any information to a group of multicast receivers in the presence of multiple eavesdroppers. Also, assume that there is no direct link between the source and the receivers. So, to transmit the data, the best relay selection scheme is utilized to choose among multiple relays.
In this case, is the perfect channel state information (CSI) of both receivers and eavesdroppers necessary for applying the best relay selection scheme?
Cooperative relays have been studied to enhance the physical layer security. Node selection and artificial noise generation are used to degrade the performance of eavesdroppers. Recently, intelligent reflective surface(IRS) has also been introduced to improve the PLS. Therefore, Which one is better?
It is well known that fast fault clearance is of vital importance for the High Voltage Power Systems, but unfortunately in Distance Relay protection, the faults on the protected HVTL near the remote end substation postpone to the 2nd zone which includes time delayed.
For example, let's assume a fault external to the microgrid in which the voltage and frequency levels are outside the ride through range. Which protection should act first: 27, 67 or 81? Could a directional overcurrent relay act faster than a frequency relay in these conditions?
and also when a DLBCL patient should be tested for the ALK ? currently, i relay on the morphology, is that enough?
I'm working on a PFC Totem pole for an On Board Charger application.
I would like to know how to manage the soft start procedure to slowly charge the DC link capacitor and so limit the inrush current.
I know that a PTC (or NTC) thermistor can be used with a relay. I also read that the DC voltage reference (the ref of the outer voltage loop) can be slowly incremented (a ramp).
It's really confuse :
- When should I open and then close the relay to short the thermistor (time? DC voltage reach a defined level? loop are in steady state? ...)
- What about the DC voltage reference? When should I start to increment it? from 0 to 400V?
- What about the state of MOSFETs during soft start procedure?
- How to simulate in Simulink the system Thermistor+Relay
Thanks a lot for your precious answers !
Suppose there is a mobile device at the edge of a cell of a 5G wireless network which has a weak channel with the base station. The edge user can utilize relay assisted D2D communications proposed for 5G. Assume the edge user broadcast a call and expect it to reach at least one neighboring relay. How can the reliability of the broadcast call reaching at least one neighboring relay be mathematically modeled for 5G by taking 3GPP standards into consideration?
I need help in understanding the mechanism to measure/estimate health of DC contactors and DC relays used in industrial grade power systems. What are the mechanisms and tools used for this purpose ?
Please share links for the material or the material itself.
Thanking in advance.
I am simulating a Mechanical DC circuit breaker. I used a step to put on and off. I wanted to use a "compare to constant" block so that when the fault current goes over the threshold the ideal switch can trip. The step is connected to the ideal switch so I cannot connect a relay too. Any help will be much appreciated.
Several pieces of research model this self-interference (SI) using different random distributions like Rician, Nakagami-m, Rayleigh, etc. The cancellation techniques allow the SI suppression up to a certain level and only a very small amount of residual SI remains. According to my understanding, due to the presence of transmitting and receiving antennas at the same node the LOS component will dominate that can be canceled using cancellation techniques. But due to multipath effects, the residual SI component is very small.
I want to switch the diesel generator from the relay output interfaced between PLC and diesel generator starter for automatic switching. How this can be achieved. Is there any circuit design. Is 8 leg relay of 30A is suitable for this? If your answer is yes. Kindly explain the circuit design and interfacing mechanism to switch the generator for its automatic action.
I need analysis the ergodic achievable rate in paper " Exploiting Full-Duplex Two-Way Relay Cooperative Non-Orthogonal Multiple Access ". i'm using Matlab 2016a.
analytical base on (33) (34) (35) (36) in paper attach
Distance relays respond to a ratio of voltage and current at the relay location, this ratio is in the form of impedance, as the impedance of a transmission line is proportional to its length. This concept is used for locating the location of the fault in a transmission line, via distance measurement.
Thus a relay capable of measuring the impedance of a transmission line up to a predetermined point is used, known as as the distance relay.
During the test of the power swing function in distance relay (Micom p441) using the continuous shots from no tripping area to zone 3 in a specific length (1 second), when I use 20 shots the relay detects it as a fault, but when I use 25 shots the relay detects it as a power swing. Why this happens?
How does the electrical industry detect faults (LG, LLG etc) in the transmission grid?
- Using voltage sag for fault detection & location?
- Using overcurrent magnitudes for fault detection & location?
- The analysis is performed using voltage/current AC waveforms or RMS (DC equivalent) waveforms?
- Which equipment/s are used do we employ relays for this? Is there a relay which detects voltage sags?
Will be highly obliged if someone can answer the above queries. Thank you
For research I'm doing, it is possible to convert a cellular relay base station's radiation power intensity to a transmitted power from this cellular station?
Hi everybody, I want to make a rigid endoscope with Hopkins relay system but I have only a little information about Hopkins relay system and lens.
I want to get information about the lens material and design it.
Do you have any information that can help me or do you know the book, article or site that helps me?
What do you think about the interoperability of Low power wide area IoT devices belonging to different LPWAN technologies? As a subset of LPWAN IoT protocols operates in unlicensed sub-GHz band (like LoRa, Sigfox) while some other protocols operate on licensed spectrum (NB-IoT). How is it possible to make them integrate/compatible with each other? How about relaying both LoRa and NB-IoT through a single gateway?
I think the latest developments in optimal relay coordination are adaptive settings of relays in the presence of Distributed generation. what is the area in which i should do research in pursuing PhD?
In Overlay model both PU and SU coexist while SU know the coding technique used by PU for two reasons, first to avoid PU interference and second to help PU in relaying his messages.
Detecting if the Neutral Ground Resistor (NGR) is shorted is something that must be checked at the Ground Fault Protecting Relay. The typical way to do this is to inject a DC component and to measure the voltage drop in the NGR. If no voltage drop is seen, it is assumed that the NGR is shorted and the relay trips. I would like to have Wye-connected PTs, used to monitor the quality of line to ground voltage and NGR monitoring with NGR short circuit condition detection at the same time on a 4160 V transformer secondary.
Having Wye-connected PTs may confuse the ground fault detection relay as for the DC component the PTs provide a low impedance parallel path which can be confused with a shorted NGR and this must be avoided.
Is adding a Potential transformers Ground resistor (PTGR) the only way to achieve both things? Wouldn't this affect the reading of the system monitoring the quality of line to ground voltage?
Update: There are also PTs that are build with a capacitor voltage divisor on their primary but I haven't found any operating at 5 kV
Can anyone share the research papers related to adaptive relaying scheme for the AC grid with VSC-HVDC connected offshore wind farms?
Sherpa is one of the systematic prediction methods for human error .
What do you think should be done to reduce the human error in testing relay protection?
I'm trying to calculate the queuing time on the relay nodes so as to chose a routing path in a less avg. queue time. My I get any one who works around? I'm using a ns2. Any response is appreciated!
That is suppose there are 2 nodes A and B in a given Network topology. Assuming that we assigned the queue length=50packets for each. Let a number of packets are sent to those two nodes. Here my question is how can I know the number of packets that are waiting in a queue in each nodes so that the next packet should have to be sent to a less queued node? Is there any mathematical formula to determine this if you knows??
The data has been given. I have done the simulation in Simulink. Now i want to use relaying logic for the fault at any Load bus say bus 4. but i am unable to find the load current. Can anyone help me with the load flow analysis of system? No internal impedance of generator is given so i considered to have 0.15 pu of reactance.
for single relay , theoretical BER is = 0.5*(1- (g/(1+g))^H/2).
g= SNR ( say same for each hop) . g= (mod(h))^2 *E/N ; H= no of hops
as per the published paper- ' End-to-End Average BER in Multihop Wireless Networks over Fading Channels ' in that paper, simulatin result is same (100% same result)as this mathematical expression.
but when I am trying to implementing it in MatLab , result is not nearly same.( difference in BER= 0.01 max) but not exactly same.. why?
can anyone send me Matlab Code for Decode and Forward simulation of cooperative scheme??
In a system, one source (S), one relay(R) and multiple users are connected with a relay, S and R have multiple same number of antennas, however all other users have same number of antennas. One can calculate the SINR for single receiving antenna by users, but how about multi stream transmit antennas from R to users, precoding matrix is considered?
In wireless communication systems relays will improve the performance, capacity and energy consumption of the system, lets say I want to employ multiple relays between the source and destination node, some coding methods i need to employ so that signals will be transfered coherently. My question is that which technique is more suitable to apply, either Precoding or STBC?
Your comments will be highly appreciated.
I am working on NOMA in cooperative relay networks, i am trying to replicate the results of jouranl paper, where noise power of AWGN is set as -114dbm (3.9e-15 in decimal), as it is very small value, which makes transmit SNR very high and in turns outage probability is always zero. I want to inquire that whether "noise power" is same as "noise variance"?
I want to control the heating element so as to maintain the temperature of the steel plate at 150. I am considering two options. 1. Using a PID temperature controller connected to the heating element and a power supply. 2. Using a relay and a DAQ card with the input of the relay connected to power supply and the DAQ card while the output connected to the heating element. which thermocouple is best for temperature measurement of the steel plate. Anybody with any useful advice
I am looking for the design of quadrilateral characteristic-based distance relay.
whether the relay setting for phase and ground distance relay is same or different?
Suggest your idea or some reference materials.
I want to switch to autotuning of the PID values rather than doing manual autotuning. I want to know all the possible resources for that. Please advise.
We have a 220/33 kV Substation and 100 MVA transformer, YNyn1, primary of which is 400/1 CT with RET-615 relay and secondary of transformer is 2000/1 with REF-630 relay. For an outgoing feeder earth fault, both the outgoing feeder and transformer secondary are tripping simultaneously on master trip 86A and 86B.
IDMT stages are properly co-ordinated and
The high set earth fault setting for outgoing feeder is 216 A @ 0.2 sec
The high set earth fault setting for transformer secondary is 1600 A @ 0.4 sec
Still the transformer secondary is tripping for outgoing feeder fault. We even checked the phase currents obtained during the earth fault and overcurrent relay pick up settings, but even they are clearly co-ordinated with 0.2 time margin.
What could be the probable cause of such tripping?
I am a bit confused with pesticide half life. As far as I know, it is used for environmental purposes.however, if a pesticide is systematic then the biological process would deal with it during the waiting period but if a pesticide is by conract, dose it have the same waiting period or do we relay on the washing step to remove the residues fron the surface of fruits and vegetables.
If we relay on the weather conditions to degrade pesticides from the surface, do they have then similar time as Half-Life.
Do low, moderate and high half-lives presist in the environment somehow related to the safety of plants in fields, produced for humman consumption or as animal feeds.
In the attached circuit diagram Relay 1 is always energized. Relay 2 will be energize only if somebody presses either of the switches but with relay chattering relay 2 got energized without pressing the push buttons and started the pump.
question is how relay 2 got energized as there is no path for the current flow other than switches.
If we have two-nodes and one relay, where two-nodes can communicate with each other using the help of Decode-and-Forward relay node. How to implement it in two-phase transmission instead of three-phase??
Suppose I have a millimeter wave relay system with one BS, one relay and one UE. During beam training, assuming exhaustive search technique, can the relay simultaneously receive pilots from BS and transmit pilots to the UE for the purpose of beamtraining. The Relay can be considered to be operating in half duplex mode, for example, it listens to the pilots from BS in a band and transmits the pilots to the UE in a different band simultaneously.
If that is the case, is it correct to consider that the beamtraining or the cell search latency for the entire BS-Relay-UE link is maximum of time taken between of BS-Relay link and Relay-UE link?
Plants communicate each other in a chemical way rather than electronically. Can we use it for human communication purpose? For instance, a transmitter sending message to a plant then this plant relays message chemically to other plant, the chemical message is then converted by a receiver. Any existing research?
i am working on indoor relay in lte-a but i am missing codes to show the improvement of multi-hop relay for indoor compared to single hop.
We have different schemes for the compensation of fault resistance because it affects performance of conventional ground and phase distance relays.
But which are the cases in which the high resistance faults occur? And how many percentages of these faults occur as compared to dead short circuit faults (means the faults with negligible fault resistance or fault impedance)?
- Is there one regulator device that can supply at least 1.2 Amps @ 5 VDC from a 9.8 - 14.8 VDC battery and also draw below 150uA in quiescent mode? I am currently using two regulators for this requirement. I must completely cut power to the high current regulator to achieve a 150uA sleep current as the quiescent current of any 1.2 Amp device I have seen is well above 150uA.
- The high current regulator is powered on for one minute and off for 9 minutes.
- LM2936 is used for the low quiescent current. 7805 type is used for the high current regulator. The high current regulator is powered on and off by a PVG612 optical relay as this device has very little off state leakage. This designe is from 17 years ago. Surely now there is a single device that can do all this without creating so much heat.
- This regulator system is used to power a microcontroller that charges batteries and controls the telemetry devices for my agricultural research project published here. Thank you in advance.
I am considering putting a ground relaying scheme for a generator. Does the specification of the transformer play a role in the generator neutral current?
Any suggestion or reference is highly appreciated.
I am working on a Power system transmission lines protection, i need a distance relay design for analysis...
I have a DC-DC converter (input rating 9-36V/5.9A and output 12V/3.4A). I am supplying power to this DC-DC converter using a power supply rated (12V/10A).
This power supplied by this DC-DC converter (12V) is then relayed on three 24AWG conductors (max current capacity of 577mA).
What should be the rating of the fuse which I should be placing at the input of the DC-DC convertor?
Help or suggestions would be greatly appreciated.
In the conventional start/stop relay circuit, an additional ("holding") contact is connected in parallel to the start push button.
But what do we do when there is no such an additional contact? Or if there is no contact at all (for example, instead of a relay there is a solenoid)? Can we still make a "relay latch" with simple means?
I hope to make a compact electric circuit to control my module.
Because module size is very small (diamter=11 mm, length=30 mm), I can't use general timer relay.
My module operates as follows.
Signal input (Switch on) > first part actuating(latching part is melt) > time delay (for example 5 sec) > second part actuating(latching part is melt)
I can use just one signal, not two, so I try to actuate second part by delaying turn on timing. In case of the macro size system, it is very easy condition but size limitation interrupts me. As I guess, some IC chip or timer(ex. NE555) should be utilized like this case. Or is there any micron timer relay?
I will make a custumized PCB after fixing electric circuit.
In order to ensure the best QoS in cooperative systems, which relaying protocol should be preferred : Regenerative type (Decode-and-Forward : DF) or Non-Regenerative type (Amplify-and-Forward : AF)? Kindly provide some reference(s), if available. TIA.
In Pakistan currently we are facing black outs in many areas due to false tripping of relays caused by flash overs due to severe foggy weather in the areas. Your kind suggestions are most welcome.
I dont have question i only say thanks a lot Dear Prof Dr. ( Emil Roduner).
Relay I understand (why nanomaterials are different) thanks a lot for your paper thanks for you
I think this is more important to understand the nano size
I am interested to know the latest trends adopted for distribution system protection. I would be very thankful to you for answering the following questions;
1) What are the modern trends used in various power distribution networks for protection?
2) How is protection coordination maintained in modern distribution systems in the presence of distributed generators?
3) Are the settings of relays kept fixed or changed as per prevailing power system conditions?
4) Does adaptive protection exist in the modern distribution systems?
Thank you so much for your contribution to this thread.
With best regards,
M. N. Alam
I'm working on mitigating frequency shift wireless communication links suffer from in case of the two communicating parties are moving relatively to each other (Doppler effect).
In some cases frequency shifts happen very rapidly, so I need to know what are the practical limits of an oscillator following these changes if they are already determined.
e.g. is it possible to program a VCO to shift its frequency one step up/down every 4 microseconds? or will the VCO, or oscillator, fail to respond in such short period?
I am confused about the value of power supply of the ICs uln2003 and uln2004 which drive some relays. I have seen different opinions in the internet or the datasheet of the ICs. Moreover the maximum input for the uln2003 is 3V and for the uln2004 is 8V? Can someone help me?
Thanks a lot in advance!
I have chosen a relay which has max switching voltage 440V rms(datasheet value). However, the particular relay must withstands 500 V rms minimum. Is this going to cause a problem to my circuit?
i have done phasor estimation of voltage and current quantities.
i have attached the code for quadrilateral.
and i don't know how to give trip signal, like what should be coding?
What are the advantages of half cycle fourier transform over full cycle specifically for distance relaying scheme.
*Current system I am using: 3i 4 laser, CSU-X1 system with an Evolve 512 camera running of off a Zeiss Cell Observer.
Interested in if anyone is using a relay lens to fill the chip with the new large format sCMOS cameras.