Questions tagged [hvdc]
High-voltage, direct current electric power transmission systems use direct current for the bulk transmission of electrical power instead of the more commonly used alternating current.
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70 views
Connecting many LEDs in series on HVDC
Is it technically possible to connect, lets say 500 2V LEDs on 1000V DC line? As far as I understand, the voltage would simply be divided in 500 for each identical LED, right? Is it safe to do that? ...
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1answer
48 views
Can a flyback transformer voltage output be multiplied by a Villard cascade?
I'm trying to keep the setup rather simple for a high voltage power supply I'm making. I'll probably use a ballast to drive the flyback as opposed to perhaps a ZVS board -- feel free to critique this ...
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1answer
60 views
Deriving equivalent impedance of circuit with pi sections
Hello everyone, I am currently trying to find the equivalent impedance of this circuit. The circuit consist of a load C1 which are connected to a two pole pi section with line inductors which are in ...
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33 views
What does pole rating and bipole rating mean for HVDC transmission cables?
I was just reading on HVDC underground cables. And according to the picture below, as they were listing out the parameters of the cables used, they mentioned pole ratings and bipole ratings.
How are ...
2
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1answer
60 views
Electrospray Deposition
I recently got a new project to work on, an Electrospray Deposition setup. Basically, it consists of a needle that contains a liquid, a electrode and a high voltage source. The needle is positioned at ...
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1answer
76 views
Harmonics produced by LCC converters
Considering an LCC HVDC system and that the flow of power is ALWAYS in the direction shown in the figure.
I know that converters in general produce harmonics.
My questions are:
Does this HVDC system ...
4
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2answers
116 views
current path into the ground?
Considering a monopolar HVDC system, with the ground as the return path.
I was wondering if the current path is physically speaking like the red one or the green one in the picture? I think it is like ...
0
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1answer
42 views
Reduction of the harmonic currents in LCC HVDC systems
Why there is a reduction of the harmonic currents in the AC side in an LCC HVDC system?
Here is represented the AC current in yellow, in red the DC voltage and the sinusoidal waves are the AC ...
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1answer
148 views
What are the situations which can cause a resistor to permanently increase its resistance?
The resistance of a resistor in the HVDC circuit permanently increases.
Is it because of voltage or some other reasons?
Note that there are no short circuit cases seen in the system.
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289 views
Unstable behavior of Dc-Dc converter
I am currently working on a high voltage boost converter based on Dos4Evers 555 timer based one https://www.dos4ever.com/flyback/flyback.html (12v to 140-220V). I am running into an issue with the ...
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2answers
110 views
Can anyone explain HVDC transmission to me?
HVDC transmission system sounds strange to me because I wonder why we would need it?
We have HVAC transmission system which is much more efficient and less power losses. When we use the DC for same ...
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2answers
409 views
What is this symbol that looks like a 3/4 circle connected to wires?
I am reading an application guide related to high-voltage DC and have come across a symbol that I do not recognize:
The source of the schematic is this document from Siemens.
Based on the context, ...
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4answers
912 views
High Voltage (0-600V) DC Voltage Sensing, Shared Ground with Isolated Converter and HV-
I'm designing a circuit to detect when the voltage across two DC input lines (HV+ and HV-) is greater than 60V. The voltage will vary from 0-600V. A seperate supply of 12v and 5v is available for use. ...
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0answers
60 views
How to change polarity at 120V DC using DPDT?
I have a strand of LED Christmas lights. Each "bulb" has two LEDs - one is color and the other is white - the polarity on the string determines which of the two LED lights up. Pressing the button ...
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2answers
194 views
Physical Limits on HVDC Voltage [closed]
Higher Voltage minimizes I^2*R losses in power lines - we have power lines up to 1 megavolt, and presumably going any higher in terms of voltage doesn't save you too much power.
But say we do ...
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1answer
100 views
Does using HVDC for distance transmission make theft of electricity easier to detect?
In particular, if you were going to try to steal power from HDVC transmission lines you'd need one cable attached to current going in 1 direction and the other attached to current flowing in the ...
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0answers
251 views
High voltage pulse discharge ring dampening (how to save a pulse capacitor)
So I have a high voltage pulse circuit. I have planned it to be around 90kv with the capacitor being 1.3uF. It is to be discharged through a spark gap. Before I test it, I of course want to save the ...
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4answers
2k views
High voltage LED indicator 40-1000 VDC without additional power supply
I would like to make an indicator to show that DC bus (700VDC) capacitors are charged (be careful!).
What is the best way to make a LED indicator, which will work for a long time from 40VDC to ...
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2answers
416 views
What limits the number of MOSFETs/IGBTs in Series / Parallel
I was looking at HVDC systems out of curiosity and I have a question that I have not exactly found an answer for.
In HVDC converter, because of the high voltage (Tens/Hundreds of kV) they have to ...
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1answer
166 views
High voltage to low voltage buck converter for(60V IN 5V 3A out) making noises?
I've been trying to convert a high voltage input to a lower voltage (5V at around 3A) with no luck using these Modules
and all of the LM2596HV iteretions of modules out there and all seem to make ...
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2answers
120 views
Voltage Drop for Power Supply Testing
I recently bought a 10-30 kV DC, 8-10 mA power supply that I am looking to test before its incorporation. However, the retailer advised me that I should place a load on this power supply - as one ...
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1answer
221 views
Are Newfoundland's and Quebec's power grid synchronized [closed]
By the Maritime Link project (HVDC), which finished this year, Newfoundland is linked asynchronously to Nova Scotia, which is part of the Eastern Interconnection.
But is the power grid of ...
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1answer
31 views
Switch in parallel to a hvdc load. Fail or success?
Suppose I have 600v dc as my power source to a motor. And I have a isolation relay in parallel with the motor. The motor runs when the switch is open. What happens when the switch is closed?
Would ...
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0answers
147 views
High Voltage Serial-to-Parallel Over Many Channels
I've been using the HV507 for parallelization of a 300VDC supply, but the chip only has 64 channels. I was wondering how to drive this voltage to a much higher number of channels (say, 1,000).
Is ...
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1answer
236 views
How can I protect a picoammeter or a picoscope in HVDC measurements?
I'm trying to measure the leakage current along an insulator energize with HVDC (the effect of space charges is been considered).
Can I connect a picoammeter to the ground electrode? If yes, please ...
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2answers
896 views
Switching HV DC relay on crashes microcontroller
So I´ve designed a PCB for a Pre-/Discharge Circuit for a 400V DC system which is controlled by a STM32 microcontroller.
When powered the program waits for 1s and then starts by switching the (...
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1answer
219 views
Relay to Tesla Coil [closed]
If you take apart a Relay (small, mine is out of a printer) and open it up there is a tall coil of wire. Are you able to use that coil of wire to make a HV generator or Tesla coil of a sort?
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2answers
5k views
Why does HVDC consume reactive power
So many academic papers quote the following fact:
"A line commutated converter in steady-state operation inherently consumes reactive power of about 60% of the DC power transferred."
I do not want to ...
2
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2answers
626 views
Optoisolator Long term Reliability at HVDC
Most optocouplers spend most of thier time isolating mains voltages.They are reliable doing this and they are cheap and simple.How would things go if the same garden variety opto was isolating a DC ...
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0answers
2k views
Why DC is not used for long distance voltage transmission? (Tesla vs Edison 2015) [duplicate]
It seems this question has been marked duplicate but I believe the answers given here is much more in detail.
Why we are still using AC voltage for long distance voltage transmission. As we know with ...
asked Jan 12 '15 at 2:11
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2answers
475 views
Why are thyristor stacks hung from the ceiling?
The Wikipedia article on thyristors as well as the one on valve halls mentions that thyristor stacks in HVDC applications can be hung from the ceiling or supported by insulators mounted on the floor. ...
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6answers
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Extract 5W low voltage power from 3000W high voltage source
I have a solarpanel array that generates 600V, 5A (3kW). I want to create a small electronic unit to measure the DC current and voltage and transmit this wireless. For this I have an electronic board ...
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1answer
2k views
SMPS design, requirement of generating High Frequency
Question:
Is that requirement of converting 50Hz to a higher frequency in SMPS (Switched Mode Power Supply) is just to reduce the transformer/inductor core size?
Background:
Since as we all know ...
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4answers
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How does DC transmission require several times less wire than AC?
In this YouTube video (scrolled to 5:55) there's a claim that replacing an AC high voltage transmission line with a high voltage DC transmission line allows for having seven times fewer powerlines (...
