Why is residential wiring known as single phase?

[mivey]

Posted quite a few what; descriptions of the effect of "phases" or definitions of what phase is?

Definitions.

You aren't obligated to accept any of the definitions I use, but at least one is IEEE Std. 100 sourced. You've never once shown how I misapplied it.

Yes I have. Many times. I have also concurred with others where they have demonstrated your mis-application.

It is self-fulfilling for you to declare a particular application as the only correct use of a definition, then further declare that the definition has not been mis-applied because it was used according to the first declaration. That is like someone starting a one-person contest then declaring themselves the winner.

 

[mivey]

Thank you. This is correctly stated.

Well, a celebration is in order.

 

[Rick Christopherson]

Well, a celebration is in order.

Almost. Because you have never acknowledged that what you have previously stated was not correct.

 

[mivey]

Well, a celebration is in order.

For the remainder of the group that do not think they are called phase shifts:

The phase shifts are not time shifts but are the results of taking voltages from different terminals and in different winding directions. These physical manipulations do not produce time shifts like we would get through an impedance delay. Anomalies will occur at the same time relative to a single t₀.

What does change is the location of those anomalies relative to the peak of the phase-shifted waveform. That is how the time-related phase shift and physical-related phase shift are related: the location of the t_peak point is shifted (or whatever characteristic location on the wave we use as a time reference).

Unlike the majority of the usage of "phase shift" in the audio world, we in the electrical world do not have to have an absolute time shift to have what we call a phase shift. The shifts caused by taking voltages from different terminals and in different winding directions are called phase shifts as evidenced in references I have provided. It is common industry terminology and to say otherwise is to ignore simple fact.

I provided a few reference quotes in #1744 but here are a few more:

Introduction to Electronics, Gates:

How the transformer is wound determines whether it produces a phase shift or not. the application determines how important the phase shift is (Figure 18-5).
NOTE: THE PHASE CAN BE SHIFTED BY SIMPLY REVERSING THE LEADS TO THE LOAD.

Figure 18-5: A transformer can be used to generate a phase shift. {Pict #1 shows a reverse polarity connection with the caption "a transformer with a 180? phase shift"}{Pict #2 shows an in-polarty connection with the caption "a transformer connected to produce no phase shift"}

http://basler.com/downloads/3phXfmrs.pdf
Three Phase Transformer Winding Configurations and Differential Relay Compensation, Basler Electric Company:

In order to get other phase shifts, some configurations may invert polarity connections, change which side of the winding the bushings are connected to, or introduce a 120? phase shift by swapping the U, V, and W bushings connections.
...
The error current equation below assumes the relay is configured in such a way that current into one winding set and out the other winding set results in positive current into one input of the relay and negative current (i.e., 180? phase shift) into the other input.

http://www.transformerworld.co.uk/vector.htm
From the connections table in the reference we see that a winding reversal gives a 180? phase shift:

By connecting the ends of the windings in other ways a wide range of options becomes available as set out below.
...
Phase shift (deg) = 0 : Yy0, Dd0, Dz0
...
Phase shift (deg) = 180 lag: Yy6, Dd6, Dz6

There are hundreds upon hundreds of references available that show our industry refers to these "not time shifts" as "phase shifts" and here are a just a few from a quick search:

http://ecmweb.com/ops/electric_basics_transformers_2/

http://www.geindustrial.com/publibrary/checkout/DEQ-165?TNR=FAQs|DEQ-165|generic

http://opencourseware.kfupm.edu.sa/...Lesson_Notes_Lec_11_3_phase_traqnsformers.pdf

http://www05.abb.com/global/scot/sc...quirements on hvdc converter transformers.pdf

http://xnet.rrc.mb.ca/janaj/differential_protection.htm

http://nptel.iitm.ac.in/courses/IIT-MADRAS/Electrical_Machines_I/pdfs/1_13.pdf

http://www.butlerwinding.com/store.asp?pid=28351

http://www.basler.com/downloads/solutionsforunconv.pdf

http://nptel.iitm.ac.in/courses/Web...uits/lecturers/lecture_22/lecture22_page1.htm

 

[mivey]

Almost. Because you have never acknowledged that what you have previously stated was not correct.

Then we can just have a partial glass of celebratory liquid.

 

[Rick Christopherson]

The phase shifts are not time shifts but are the results of taking voltages from different terminals and in different winding directions. These physical manipulations do not produce time shifts like we would get through an impedance delay. Anomalies will occur at the same time relative to a single t₀.

See, I told you it was premature to celebrate. These are not physical phase shifts. They are only mathematical. Arguing their validity with mathematics is a circular argument.

 

[mivey]

See, I told you it was premature to celebrate. These are not physical phase shifts. They are only mathematical. Arguing their validity with mathematics is a circular argument.

We physically make changes to the voltage terminals and directions, and these results are physically measurable, and they produce physical results. The math models the physical.


Add: Lunch is over so back to work.

 

[Rick Christopherson]

We physically make changes to the voltage terminals and directions, and these results are physically measurable, and they produce physical results. The math models the physical.

That's correct, but the math is not the physical, it only models it. That's why your mathematical model does not appear to result in a time shift. A physical phase shift will.

 

[gar]

120315-1342 EDT

The IEEE definition say "a function" not two or more functions. Comparing a function with its inverse is not one function being compared with itself, or a displacement within a period, but a comparison between two functions.

Further, in your statement

At t0 = 0, two of the functions are zero and have identical periods of 360?. Throughout the period P, at any time t, they have the identical ?fractional part t/P of the period P through which ? has advanced relative to an arbitrary origin? (t0).

Therefore, those two functions have the same phase.

It seems to me you are saying the two functions have the same frequency or period.

What is your basis for the "therefore", and it also seems that being 0 at t₀ is of no importance? If the frequencies are the same and t is the independent variable of interest t/P for any number of functions is the same. Doesn't prove anything about the phase difference between two functions.

.

 

[mivey]

That's correct, but the math is not the physical, it only models it. That's why your mathematical model does not appear to result in a time shift. A physical phase shift will.

By "physical shift" I mean we physically take voltages from different terminals and in different directions in the windings. I am contrasting that with a time shift that occurs through a delay box like we would get with a propagation delay or through an impedance.

It does not matter if you agree that a physical shift is different than a time shift because you are free to define your own terms. I'm just telling you what I mean by a physical shift in a transformer application. Call it what you want.

 

[Rick Christopherson]

Unlike the majority of the usage of "phase shift" in the audio world, we in the electrical world do not have to have an absolute time shift to have what we call a phase shift. The shifts caused by taking voltages from different terminals and in different winding directions are called phase shifts as evidenced in references I have provided. It is common industry terminology and to say otherwise is to ignore simple fact.

When you have to "condition" your answer to "limit it" to a specific field in electrical systems, it is a pretty good indication that it is not a fully true statement. Power systems is only a small portion of the electrical field. When something applies to one field but not others, then is it a sign that it is merely a convention, and not a fact. My background in electrical systems is not limited to power systems, but runs the full gamut of all electrical systems.

By "physical shift" I mean we physically take voltages from different terminals and in different directions in the windings.

And that is a physical inversion, by its definition, not a time shift or phase shift. Doing so results in a negative sign, that you may mathematically transform into a phase shift (if you wish). Even mathematically, it has to start with an inversion before the phase shift transformation takes place (remember the days when you were required to "show your work"?)

 

[Rick Christopherson]

And that is a physical inversion, by its definition......

To further claify:
The voltage between two nodes is defined as the difference between the voltages of each node. This is a subtractive operation. The voltage between nodes A and B is defined to be either V_A-V_B or V_B-V_A depending on the chosen direction. Changing the direction simply changes the operation of the subtraction. That is by definition, an inversion, and it remains true regardless whether the node voltages are periodic functions or not. The phase-shift transformation is true only for periodic functions, and that is because it is a mathematical transformation, not the physical transformation from which it was derived.

 

[rbalex]

120315-1342 EDT

The IEEE definition say "a function" not two or more functions. Comparing a function with its inverse is not one function being compared with itself, or a displacement within a period, but a comparison between two functions.

Further, in your statement
It seems to me you are saying the two functions have the same frequency or period.

What is your basis for the "therefore", and it also seems that being 0 at t₀ is of no importance? If the frequencies are the same and t is the independent variable of interest t/P for any number of functions is the same. Doesn't prove anything about the phase difference between two functions.

.

Are the two functions discussed periodic?
Do they have the same period P?
Do they have the same origin arbitrary, t₀?
Do they have the same the same t/P as they advance from t₀?

 

[rattus]

Ever notice how some people are like sleazy lawyers. They raise a cloud of silly objections in an attempt to obscure the truth.

 

[rbalex]

Ever notice how some people are like sleazy lawyers. They raise a cloud of silly objections in an attempt to obscure the truth.

Are you saying you don't know the answers?

 

[Besoeker]

Actually, I see these are SCRs, which really makes this an asinine question since they can be triggered by anything, and you don't show the triggers. Nevertheless, the above comment is still true.

They can. But to make the circuit operate correctly there needs to be TWO trigger pulses per cycle.
I asked you why.
Can you address that please?

 

[Rick Christopherson]

Ever notice how some people are like sleazy lawyers. They raise a cloud of silly objections in an attempt to obscure the truth.

Ever notice how some posters avoid those questions in an effort to deflect away from those arguments for which they cannot defend?

That's dishonesty in debate.

My discussion is the direct result of something that you, Rattus stated (as well as Mivey and Besoeker), and I have previously quoted all three of you making these statements that I contend. Yet you refuse to even acknowledge the statements or their contention.

You counter with trivializations, deflections, and attacks. Whatever it takes to not answer the claim put before you regarding your own comments.

Your last response (prior to this one) was to try to bring in a topic that I am not contending. For no other purpose but to claim some sort of false victory in your methodology of dishonest debate.

You made the original statement.
I am contesting it.
You continue to dodge the defense of that statement.

That is dishonesty in debate.

 

[Besoeker]

At t₀ = 0, two of the functions are zero and have identical periods of 360?. Throughout the period P, at any time t, they have the identical “fractional partt/P of the period P through which ƒ has advanced relative to an arbitrary origin” (t₀).

The fractional part is 180 degrees. Pi radians.
It is thus not an identical fractional part.
They are thus not in phase by your definition.

 

[Rick Christopherson]

They can. But to make the circuit operate correctly there needs to be TWO trigger pulses.
I asked you why.
Can you address that please?

Yeah, one trigger on the positive half-cycle, and one on the negative half-cycle. It is an illogical argument because it is a circular argument. It neither proves nor disproves anything. Your circuit is not a point of contention, but you are trying to make is sound as though it is. Your statements are the point of contention. Your circuit neither refutes nor supports your statements.

 

[rattus]

The fractional part is 180 degrees. Pi radians.
It is thus not an identical fractional part.
They are thus not in phase by your definition.

Not by any definition; neither are they 'of the same phase'.