4 Wire Wye Vs 4 Wire Delta - New Construction

[mbrooke]

Nail on head. End product. It would need all existing units to be ripped out and replaced with something much larger, more complex, and much more expensive.

Correct, but bear in mind units age, plus we dont know if these new devices will cost a lot more.

I don't know how much you've played around with DC on any significant scale. I've designed and installed systems up to 40,000Adc. Others up to a few thousand volts. Some water cooled, some force air cooled, some air natural. They were all specialist applications that really needed DC. I can promise you that DC is an entirely different beast. And I intentionally used that word.

I know, it has very different properties. Most which make it far superior in super grids.

A little salutary tale.
We did a converter for the VSOE, the Orient Express. It was a resurrection of that one made famous by Agatha Christie in "Murder on the Orient Express".As I said, A luxury train that crossed several European countries. The input had to cope with all the frequencies and voltages on the line between countries. Including 3000Vdc.
It was tested in the railway lab in Vitry on the outskirts of Paris. At 3000Vdc, a fault was simulated. At the time, we couldn't get 3000Vdc rated semiconductor fuses so we put three 3kV AC fuses in series.

Big mistake. They didn't clear the fault and ended up as a molten mass in the bottom of the enclosure.
As I said, DC is an entirely different beast and demands a different level of respect.

This only happened because a product was not on the market to handle the challenge. Before DC goes big, design, testing and production of DC OCPDs will already be in full swing.

Really?? For a gas compressor rated at 6,600kW? About 9,000hp.

Ok, 400 watt opti coupler. Either way I dont think this will be an issue.

But my cell phone, monitor, laptop, printer, camera charger, Kindle, DVD player, Blackberry, and various battery operated power tools need different voltages. So you would still need different voltage converters for each.

As they have now. But let me ask you this... what if I took each one of those chargers and applied 120 volts DC to them?

With respect, I don't think you do.

Could be the case, but its not stopping large corporations (ABB, Siemens, ect) along with university research from investigating it. HVDC by itself is having a renaissance at the moment.

 

[mbrooke]

Is still better in most small communities however, content being taught maybe not as good as once was, but students get more individual attention from teachers then at large schools, social events at the school usually include everyone - which is good where at big schools many are left out of a lot of things whether intentional or not.

Small tight nit communities often have the most bullying, at least in my experience vs large diverse schools.

Schools by law must do everything they can accommodate special needs students and the money is there, but nothing exists for gifted learners.

 

[kwired]

Schools by law must do everything they can accommodate special needs students and the money is there, but nothing exists for gifted learners.

Trust me we have that and abuse of that in small schools. Shortages of facilities even though number of students is 1/3 to 1/2 the size they were 40 years ago - some of it is because of spaces needed for special needs programs.

 

[mbrooke]

Trust me we have that and abuse of that in small schools. Shortages of facilities even though number of students is 1/3 to 1/2 the size they were 40 years ago - some of it is because of spaces needed for special needs programs.

I agree these programs are abused in some places, but at least a student identified as having a disability will receive intensive support. Schools are required to have placement/planing meetings, offer resources like evaluations, make necessary accommodations and even send children to an out district placement should the need arise.

However come gifted learners its a different matter. Curriculum is based on IQs between 100 to 110 tops, and and deviation under 100 is covered by law. Exceed 110 its Russian roulette. This is the tip of the iceberg, but a good place to start:

http://www.geniusdenied.com/

 

[ggunn]

Not everyone has the same experience. Ive seen and heard enough to reach my own opinion. Telling me education is just fine is like telling an Iraq or Vietnam veteran war is puppies and unicorns.

Seriously, are you trying to convince me that you have as much more experience than I with educational institutions as Vietnam and Iraq vets have about combat? Sorry, man, I absolutely do not buy that for an instant. I have in excess of 200 college credits in three different institutions; if all college professors are as morally deficient as you claim, I must be very lucky indeed.

And by the way, there are parsecs worth of difference between "just fine" and your wide brush condemnation. I never said that there are no problems in the US educational system, but I'll take a wild guess that the things you think are wrong and the things that I think could be improved upon don't have much, if any, overlap.

We are skirting the fringes of discourse that will get the thread edited or shut down, so I will stop there. Do not mistake silence on my part as agreement with or acquiescence to your conspiracy theory.

 

[iceworm]

... Of course, the only coupling between the converter's transformer will be an opti-coupler. No electrical connection will exits much like most laptop chargers. ....

I think we will need the beamed power to impliment the opto isolation. But that is okay. It will show up with the DC breakers and the 100x energy density batteries. ...

... For domestic, you'd be looking at maybe 20kW. A 20kW opto coupler?
And how would you deal with a 6,600kW gas compressor. Via an opto coupler? ....

... Nope, a single 4 watt unit will do. We only need the primary computer logic to know how the secondary of the converter is doing. .....

mb-
Stay consistent. You started with, "the only coupling between the converter's transformer will be an opti-coupler. No electrical connection will exits ..."

A couple of us pointed out that there is no energy transfer across an opto isolator. Hence the allusion to beamed power. Now it appears you are only discussing control and there will be an electrical connection for the energy transfer. So which is it. As for fiber optic isolated control across MV/HV links - maybe been around maybe 50 years. Don't know what that has to do laptop power supplies

... I get the scale, but I have a feeling you dont grasp where fate is driving this.

I can't tell you got the scale. I'm certain I don't grasp where "fate" is driving this. "Fate" sound like "predestination". I don't think you are up to that level of precognizance.

Everytime you give an absolute statement, I'm thinking, We'll see - maybe.

Bes and I are old. Doesn't make us stupid - nor ignorant. One thing I can say: After 50 years in the business, I know for certain that I don't know where this will end up in 100 years. I won't comment on if you do or not.


ice

 

[mbrooke]

This is will give you a rough idea of how a bi-directional DC to DC converter will work. Instead of having 50Hz on one side and 60Hz on the other, it will be DC to DC. All the components will be compact and modular, with the actual transformer being of a high frequency design.


https://www.youtube.com/watch?v=ZOTGuWCfS-A

 

[mbrooke]

Seriously, are you trying to convince me that you have as much more experience than I with educational institutions as Vietnam and Iraq vets have about combat?

Think about what I said first.

Sorry, man, I absolutely do not buy that for an instant. I have in excess of 200 college credits in three different institutions; if all college professors are as morally deficient as you claim, I must be very lucky indeed.

So you are trying to tell me I never set foot in any educational institutions?

And by the way, there are parsecs worth of difference between "just fine" and your wide brush condemnation. I never said that there are no problems in the US educational system, but I'll take a wild guess that the things you think are wrong and the things that I think could be improved upon don't have much, if any, overlap.

Considering gifted student have the most potential and schools fail them the most, then yes, public education is a failure. Factor in the dumming down of average students and the deal is sealed.

We are skirting the fringes of discourse that will get the thread edited or shut down, so I will stop there. Do not mistake silence on my part as agreement with or acquiescence to your conspiracy theory.

And its sad we are bound to such. :happysad: And, in case you do not reply, calling it a conspiracy is incorrect because I saw it first hand. Your life experiences do not automatically mean they apply to everyone.

 

[iceworm]

...As they have now. But let me ask you this... what if I took each one of those chargers and applied 120 volts DC to them? ....

Where are you going with this?

If you apply power to a device that is out of the design spec? It don't freekin work. OR
Are you saying, If you redesign for 120DC input - what happens? Nothing, it works.

Either way so what?

ice

 

[mbrooke]

Where are you going with this?

If you apply power to a device that is out of the design spec? It don't freekin work. OR
Are you saying, If you redesign for 120DC input - what happens? Nothing, it works.

Either way so what?

ice

Its already rectified. It will not care for AC or DC as is. So a DC system for LV will not require major redesign.

 

[Besoeker]

Correct, but bear in mind units age, plus we dont know if these new devices will cost a lot more.

Currently you have a two or three pronged device with no switch. Add a switch and a mechanical interlock and it will certainly cost more.

I know, it has very different properties. Most which make it far superior in super grids.

Superior for long distance HV transmission.

This only happened because a product was not on the market to handle the challenge. Before DC goes big, design, testing and production of DC OCPDs will already be in full swing.

I have a Cooper Bussman catalogue on the shelf in my office. In fact, it is the largest file by some margin and comprehensive. No suitable device is included. Yet.

Ok, 400 watt opti coupler. Either way I dont think this will be an issue.

A 400 watt opti coupler for a 6,600 kW machine. Care to explain how that would work?

But let me ask you this... what if I took each one of those chargers and applied 120 volts DC to them?

I don't know. Do you?

Could be the case, but its not stopping large corporations (ABB, Siemens, ect) along with university research from investigating it. HVDC by itself is having a renaissance at the moment.

Whole different ball game.

 

[mbrooke]

mb-
Stay consistent. You started with, "the only coupling between the converter's transformer will be an opti-coupler. No electrical connection will exits ..."

My mistake :ashamed1: I meant not electrical coupling.

A couple of us pointed out that there is no energy transfer across an opto isolator.

Correct, only an LED beaming light onto a photo cell. What it really is: an electronic relay. A semiconductor allen bradely.

Hence the allusion to beamed power. Now it appears you are only discussing control and there will be an electrical connection for the energy transfer. So which is it. As for fiber optic isolated control across MV/HV links - maybe been around maybe 50 years. Don't know what that has to do laptop power supplies

My point is this. The MV and LV are totally separated by galvanic isolation via a transformer. The primary logic circuit needs input from the secondary on its status. Instead of interconnecting the two electrically an opti-isolater is employed.

I can't tell you got the scale. I'm certain I don't grasp where "fate" is driving this. "Fate" sound like "predestination". I don't think you are up to that level of precognizance.

The emergence of none linear loads, large scale renewable, grid stability, long underground cables... all make AC look more impractical each day. Thats what I meant.

Everytime you give an absolute statement, I'm thinking, We'll see - maybe.

True, but I cant help to see more more pilling on the side of DC.

Bes and I are old. Doesn't make us stupid - nor ignorant. One thing I can say: After 50 years in the business, I know for certain that I don't know where this will end up in 100 years. I won't comment on if you do or not.


ice

Im not. Just saying based on my observations. BTW both of you bring a wealth of knowledge here to which I am grateful for

 

[mbrooke]

Currently you have a two or three pronged device with no switch. Add a switch and a mechanical interlock and it will certainly cost more.

Being honest I do not know what the solution will be, in fact I dont even know where to begin. :dunce:

Superior for long distance HV transmission.

And where does it become inferior for medium and short distance?

I have a Cooper Bussman catalogue on the shelf in my office. In fact, it is the largest file by some margin and comprehensive. No suitable device is included. Yet.

I know, but the HVDC breakers are the foundation.

A 400 watt opti coupler for a 6,600 kW machine. Care to explain how that would work?

You only need to know what secondary is doing, does not take much power to transfer data between motherboards.

I don't know. Do you?

The device still works. DC through a rectifier bridge equals the same DC out. Think about it. It does not care for 50, 60 or DC. This is what I am trying to say. More and more appliances do not care or will not care with little modification.

Whole different ball game.

Yes and no. The physics is the same, and very attractive

 

[Besoeker]

Being honest I do not know what the solution will be, in fact I dont even know where to begin.

You don't have to. The parts are already in existence. You'd have discard existing installations. ALL of them. Think about the sheer scale and the economics to gain what exactly.................

And where does it become inferior for medium and short distance?

The economics determine that.

You only need to know what secondary is doing, does not take much power to transfer data between motherboards.

My point was about transferring power. The data aspect already exists.

The device still works. DC through a rectifier bridge equals the same DC out.

Yes. But usually the rectifier bridge is rated based on all elements being used. For things like power supplies for printers that may be a trivial concern. Move up the power scale and it isin't.

Yes and no. The physics is the same, and very attractive

Or not so attractive when you get shafted for footing the bill.

Do you like dogs?

 

[GoldDigger]

:thumbs up:
In a four diode full wave bridge the load current will be spread over two pairs of diode when fed with AC. When fed with DC two diodes will carry the entire load.
With a combined package the heat distribution might still work out. But with discrete components there could be a problem.

 

[mbrooke]

:thumbs up:
In a four diode full wave bridge the load current will be spread over two pairs of diode when fed with AC. When fed with DC two diodes will carry the entire load.
With a combined package the heat distribution might still work out. But with discrete components there could be a problem.

Good point. But this proves in terms of functionality all these components will need is a simple rectifier re-design (or elimination in true DC).

 

[mbrooke]

You don't have to. The parts are already in existence. You'd have discard existing installations. ALL of them. Think about the sheer scale and the economics to gain what exactly.................

If we were to do it tomorrow yes, but keep in mind what is installed today will not last 150 years. Come time things change.

The economics determine that.

Yup, soley based on the price of the converter When conveters come close to the price of a typical AC substation setup DC will be a no brainier.

My point was about transferring power. The data aspect already exists.

Correct, so it is possible to have full separation between HV/MV and LV parts.

Yes. But usually the rectifier bridge is rated based on all elements being used. For things like power supplies for printers that may be a trivial concern. Move up the power scale and it isin't.

But once DC is implemented at the 600 volt and under level, you just remover the bridge rectifier and smoothing capacitor.

My point being its not like all current equipment is AC in a DC conversion will force inverters into every appliance.

Or not so attractive when you get shafted for footing the bill.

Do you like dogs?

Have you seen the AC alternative to a renewable, stable grid?

 

[ggunn]

So you are trying to tell me I never set foot in any educational institutions?

Of course not. Straw man.

Considering gifted student have the most potential and schools fail them the most, then yes, public education is a failure. Factor in the dumming down...

Heh. Irony.

And its sad we are bound to such. And, in case you do not reply, calling it a conspiracy is incorrect because I saw it first hand. Your life experiences do not automatically mean they apply to everyone.

And likewise. I did not say that my experiences were universal, but you did. I am sorry the educational system failed you, I really am. It doesn't fail everyone or even mostly everyone, and your claim that most educators belong in prison and should not be allowed near kids is patently ridiculous.

But back to the subject at hand, or at least where it has drifted...

It doesn't matter if DC distribution of power would be better; the sheer amount of heavy iron already on the ground dedicated to AC distribution is a huge obstacle to its implementation. I don't think it will be overcome any time soon. The economic incentive just isn't there.

 

[Besoeker]

If we were to do it tomorrow yes, but keep in mind what is installed today will not last 150 years. Come time things change.

Yes, they do. Is 150 years your anticipated time frame?

Yup, soley based on the price of the converter When conveters come close to the price of a typical AC substation setup DC will be a no brainier.

The rating and number of conductors comes into it too.

Correct, so it is possible to have full separation between HV/MV and LV parts.

How exactly would you implement that?

But once DC is implemented at the 600 volt and under level, you just remover the bridge rectifier and smoothing capacitor.

And fit DC rated switchgear.

My point being its not like all current equipment is AC in a DC conversion will force inverters into every appliance.

I'm not suggesting that it would. A light bulb wouldn't

Have you seen the AC alternative to a renewable, stable grid?

Norway is over 90% renewable - and AC.

 

[mbrooke]

Of course not. Straw man.

Thats my point, you can not discredit my views or say otherwise. Yes I can not speak for every school on earth, but I can speak from my experiences.

Heh. Irony.

Explain :?

And likewise. I did not say that my experiences were universal, but you did. I am sorry the educational system failed you, I really am. It doesn't fail everyone or even mostly everyone, and your claim that most educators belong in prison and should not be allowed near kids is patently ridiculous.

I never said they were universal, but considering the way public education is run (little individuality between standardized expectations and curriculum) the claim tends to hold water across the board. An example, look at inner city schools. The evidence is overwhelming these schools are several grade levels behind affluent communities. Consider the amount of kids who go to these schools, its an awfully large amount of people disadvantage. And, in general, when a kid does fail, schools put the blame on the parents or the student, never does the school over ask "are we at fault, are we doing anything wrong?"

I know this wont go far, but I think many people could have a much more rigorous education then the lowest common denominator being implemented in schools.

It doesn't matter if DC distribution of power would be better; the sheer amount of heavy iron already on the ground dedicated to AC distribution is a huge obstacle to its implementation. I don't think it will be overcome any time soon. The economic incentive just isn't there.

As time moves on, that iron will have to be replaced. Equipment will be replaced no matter what it is made out of. An example are pole mounted distribution and substation transformers. The majority of those installed in the 30s and 40s have already been replaced. Where I live entire surrounding towns had 4.8kv delta and 4.16kv Y distribution only to upgraded with 13.8kv Y in the last 10 years. The cost was huge, you bet, but 60+ year old equipment had enough.