Why doesn't long distance power tranmission cause sine wave distortion?

[Carultch]

Everytime i read the EE threads here my head hurts ,and i end up with more Q's than A's....yet i am compelled to risk a relevant (i hope) Q....

Just what is a 'sine wave'?

Way back i was told the electrons in any given atom (CU) don't necessarily 'flow' , they charge each other via some big back/forth 'bump' to any given load...

The magnitude ,or peak, was simply the flux @ certain degree of generator rotation.

Am i close....??

How the physics of VD are further altered here escapes me , but i have to start somewhere


~RJ~

Just what is a "sine wave"? Good question indeed. It isn't like it is an elementary shape that we instinctively know how to draw with a compass and a ruler.

The way that I was taught the definition of comprehensive definition of sine for all angles, was with a hypothetical roller coaster ride called the "circle of terror". It has a circular track, with a radius of 1 km. The kilometers are marked out along the arc length of the track. On the dashboard of the roller coaster, there is an altimeter and an odometer. The track is centered at sea level, so the altimeter reads zero when the coaster is half way up the track. Steve rides the roller coaster, and wonders about the relationship between the distance the cart travels, and the odometer reading. He calls this function s(x).

So sine waves are a projection of a circle's coordinate points, as you trace a given arc length or angle around the circle. Sine gives vertical, and its complimentary function cosine gives the horizontal. Mathematicians like angle units of radians, which are a radius angle. 1 radius wrapped around the circle, and the corresponding angle. It is seen as a "natural" angle unit, unlike degrees which are based on the number 360.

Sine waves are understood to be the "pure" waveform with only one frequency. The variation is as continuous as can be. Every level of rate of change for the sine wave is also a sine wave with no more than a phase shift and amplitude change. A triangle wave, square wave, sawtooth wave, or any other repeating wave shape you might imagine, is just a combination of numerous sine waves of different frequencies.

 

[mbrooke]

Nope. Magnetic field has nothing to do with it (except for niceties like Hall Effect and skin effect.)

The outermost electrons in each atom spread out (share) across neighboring atoms, causing the force that holds the metal together.
An electron with enough energy to get into those top quantum shells can move freely between the locations of different atoms in the crystal structure.

Sent from my XT1585 using Tapatalk

But without electricity, do those electrons orbit the same atom or do they switch orbits with other atoms?

 

[mbrooke]

But-going back on topic- ohms law is not a law that exists in the real world!


https://www.youtube.com/watch?v=G3H5lKoWPpY

 

[mbrooke]

Nope. Magnetic field has nothing to do with it (except for niceties like Hall Effect and skin effect.)

The outermost electrons in each atom spread out (share) across neighboring atoms, causing the force that holds the metal together.
An electron with enough energy to get into those top quantum shells can move freely between the locations of different atoms in the crystal structure.

Sent from my XT1585 using Tapatalk

And we also have this:

https://www.youtube.com/watch?v=-Rb9guSEeVE


Is it correct?

 

[Carultch]

But without electricity, do those electrons orbit the same atom or do they switch orbits with other atoms?

Without electricity, there is no electron or proton.

But in any case, without electrical energization, it is true that the electrons do switch orbits with other atoms. In metals, the electrons in the conduction band will migrate from atom to atom constantly. In non-metals, individual electrons generally remain with their origin atom and any atom chemically bonded to it. In truth, you cannot know for certain where any given electron was/is/will be. You can only know the probability that it will remain with its atom, move to the neighbor atom, move 300 ft away in just one second, or even leave this planet entirely.

Without electrical energization, the thermal motion of the electrons in a metal is chaotic, rapid, and all over the place. On net, the electrons have no systematic overall flow. The amount that flow left, will equally flow right. No net charge flows without electrical energization.

With electrical energization, what would cause a current to flow from left to right, a hypothetical electron might move 20 units to the left, and then 17 units to the right. A net move of 3 units, due to the electrical current. And yes, you read that correctly. A left-to-right current causes electrons to flow to the left. Due to the accident of history that the electron is negative, its electrical motion is opposite the direction you know "current" to be. Had there been positive charge carriers, like the sodium ions in a human nerve, they would flow with the current.

 

[mbrooke]

Just what is a "sine wave"? Good question indeed. It isn't like it is an elementary shape that we instinctively know how to draw with a compass and a ruler.

The way that I was taught the definition of comprehensive definition of sine for all angles, was with a hypothetical roller coaster ride called the "circle of terror". It has a circular track, with a radius of 1 km. The kilometers are marked out along the arc length of the track. On the dashboard of the roller coaster, there is an altimeter and an odometer. The track is centered at sea level, so the altimeter reads zero when the coaster is half way up the track. Steve rides the roller coaster, and wonders about the relationship between the distance the cart travels, and the odometer reading. He calls this function s(x).

So sine waves are a projection of a circle's coordinate points, as you trace a given arc length or angle around the circle. Sine gives vertical, and its complimentary function cosine gives the horizontal. Mathematicians like angle units of radians, which are a radius angle. 1 radius wrapped around the circle, and the corresponding angle. It is seen as a "natural" angle unit, unlike degrees which are based on the number 360.

Sine waves are understood to be the "pure" waveform with only one frequency. The variation is as continuous as can be. Every level of rate of change for the sine wave is also a sine wave with no more than a phase shift and amplitude change. A triangle wave, square wave, sawtooth wave, or any other repeating wave shape you might imagine, is just a combination of numerous sine waves of different frequencies.

Is it true that there are different types of generators that produce different types of sine waves?

 

[Carultch]

But-going back on topic- ohms law is not a law that exists in the real world!


https://www.youtube.com/watch?v=G3H5lKoWPpY

It is a myth that V=I*R is Ohm's law, but it is taught that way anyway. V=I*R, or rather R=V/I, is the definition of resistance.

A better way to state Ohm's law, is that for materials that obey Ohm's law, R is independent of V and I. R depends on size, shape, temperature, and material, but not the electrical operating conditions. It is an empirical law, which has an atomic level explanation.

 

[Smart $]

...
An electron with enough energy to get into those top quantum shells can move freely between the locations of different atoms in the crystal structure.

Yes... but in electric charge transmission, the electrons must move in unison from atom to atom. IOW when an electron moves from one atom to its adjacent atom, then one electron from that adjacent atom must move to an adjacent atom that is not the first mentioned atom...

 

[mbrooke]

Without electricity, there is no electron or proton.

But in any case, without electrical energization, it is true that the electrons do switch orbits with other atoms. In metals, the electrons in the conduction band will migrate from atom to atom constantly. In non-metals, individual electrons generally remain with their origin atom and any atom chemically bonded to it. In truth, you cannot know for certain where any given electron was/is/will be. You can only know the probability that it will remain with its atom, move to the neighbor atom, move 300 ft away in just one second, or even leave this planet entirely.

Are the last two even possible or happen in our daily lives?

Without electrical energization, the thermal motion of the electrons in a metal is chaotic, rapid, and all over the place. On net, the electrons have no systematic overall flow. The amount that flow left, will equally flow right. No net charge flows without electrical energization.

With electrical energization, what would cause a current to flow from left to right, a hypothetical electron might move 20 units to the left, and then 17 units to the right. A net move of 3 units, due to the electrical current. And yes, you read that correctly. A left-to-right current causes electrons to flow to the left. Due to the accident of history that the electron is negative, its electrical motion is opposite the direction you know "current" to be. Had there been positive charge carriers, like the sodium ions in a human nerve, they would flow with the current.

But in reality they don't flow left to right? Just like nothing flows from positive to negative in reality?

 

[Smart $]

Is it true that there are different types of generators that produce different types of sine waves?

A sine wave is a sine wave. You can make it taller or shorter, fatter or skinnier and it is still a sine wave.

 

[mbrooke]

It is a myth that V=I*R is Ohm's law, but it is taught that way anyway. V=I*R, or rather R=V/I, is the definition of resistance.

A better way to state Ohm's law, is that for materials that obey Ohm's law, R is independent of V and I. R depends on size, shape, temperature, and material, but not the electrical operating conditions. It is an empirical law, which has an atomic level explanation.

So R=V/I is 100% true all the time , because we can measure voltage and current with near 100% accuracy relaying on algebra to give the answer, however, because we can not always, at least not easily predict how the actual resistance will change with temperature we skirt the complicated math and come up with a half true equation V=I*R as a compromise?

 

[mbrooke]

A sine wave is a sine wave. You can make it taller or shorter, fatter or skinnier and it is still a sine wave.

But what determines the uniqueness?

 

[Carultch]

Is it true that there are different types of generators that produce different types of sine waves?

There is only one "type" of sine wave. Everything that would make one sine wave different from another, is either its position in time (phase), its position in average voltage (DC offset), its scaling in time (frequency & period), and its scaling in voltage variation (amplitude). Or it could be a sine wave in a different medium than electricity, like an object vibrating on a spring.

The other types of waves are superpositions of multiple sine waves. A function generator is the device that can generate theoretical low-power signals of these waves, and allow you to configure the parameters like amplitude, frequency, and DC offset.

Power generators will not produce a pure sine wave without filtering. Even so, it will usually be close enough for most loads that aren't particularly sensitive. There is harmonic distortion to even the world's simplest electric generator, due to nonlinearities in the magnetism

 

[Carultch]

So R=V/I is 100% true all the time , because we can measure voltage and current with near 100% accuracy relaying on algebra to give the answer, however, because we can not always, at least not easily predict how the actual resistance will change with temperature we skirt the complicated math and come up with a half true equation V=I*R as a compromise?

For components like diodes, where Ohm's law does not apply, it is more useful to forget about the concept of resistance entirely. Diodes have a characteristic I-V curve, that shows how at one particular voltage, the current it lets through is such.

You could talk about the resistance of a diode at a particular point on the I-V curve, but it will be a completely different value everywhere else. So it's not a useful concept.

For components where more than just resistance applies, but our V & I waveforms are still both sine waves, Ohm's law is back. But with a twist. Instead of resistance, we talk about impedance. We use a combination of a real number for resistance, and an imaginary number for the additional effect of energy storage, called reactance. We can still make the equation V=I*Z, where Z is impedance. V and I are both complex numbers themselves, which contain information about both amplitude and phase.

 

[mbrooke]

There is only one "type" of sine wave. Everything that would make one sine wave different from another, is either its position in time (phase), its position in average voltage (DC offset), its scaling in time (frequency & period), and its scaling in voltage variation (amplitude). Or it could be a sine wave in a different medium than electricity, like an object vibrating on a spring.

Can you go more into DC offset? Is this like the DC competent when a breaker interrupts fault current we must take into consideration?

The other types of waves are superpositions of multiple sine waves. A function generator is the device that can generate theoretical low-power signals of these waves, and allow you to configure the parameters like amplitude, frequency, and DC offset.

Any pics or links? Im confused...

Power generators will not produce a pure sine wave without filtering. Even so, it will usually be close enough for most loads that aren't particularly sensitive. There is harmonic distortion to even the world's simplest electric generator, due to nonlinearities in the magnetism

How so when a generator is often a pure circle? The winnings will simply reflect this pure circle and in turn produce a sine wave that is the byproduct of a pure circle and this resembles a perfect sine wave. ?

 

[mbrooke]

For components like diodes, where Ohm's law does not apply, it is more useful to forget about the concept of resistance entirely. Diodes have a characteristic I-V curve, that shows how at one particular voltage, the current it lets through is such.

You could talk about the resistance of a diode at a particular point on the I-V curve, but it will be a completely different value everywhere else. So it's not a useful concept.

For components where more than just resistance applies, but our V & I waveforms are still both sine waves, Ohm's law is back. But with a twist. Instead of resistance, we talk about impedance. We use a combination of a real number for resistance, and an imaginary number for the additional effect of energy storage, called reactance. We can still make the equation V=I*Z, where Z is impedance. V and I are both complex numbers themselves, which contain information about both amplitude and phase.

Can a diode be compared to a neon indicator?

It was a break down voltage (forward voltage?__:?) and has a negative run away resistance.

 

[GoldDigger]

In reply to post #44....

Not bad!
Conduction electrons not exposed to a driving voltage will not have any net movement in any direction, but neither are they strictly associated with one atom (nucleus.) They have a probability spread that covers a large area and may, in effect, trade places with other electrons.
When a current flows you could say that individual electrons have a net movement or you could say that the whole conduction electron cloud has a net velocity.
To get an idea of what conduction electrons are, imagine an array of positive nuclei making a dimpled potential energy plane. Some electrons sit on the slopes of the dimples. Those are the bound electrons. They effectively fill up the dimples so that the rest of the electrons (the conduction electrons) spend their whole time above the tops of the dimples, even though the whole surface has been lowered too.
They can move around freely.

Sent from my XT1585 using Tapatalk

 

[mbrooke]

Not bad!
Conduction electrons not exposed to a driving voltage will not have any net movement in any direction, but neither are they strictly associated with one atom (nucleus.) They have a probability spread that covers a large area and may, in effect, trade places with other electrons.
When a current flows you could say that individual electrons have a net movement or you could say that the whole conduction electron cloud has a net velocity.
To get an idea of what conduction electrons are, imagine an array of positive nuclei making a dimpled potential energy plane. Some electrons sit on the slopes of the dimples. Those are the bound electrons. They effectively fill up the dimples so that the rest of the electrons (the conduction electrons) spend their whole time above the tops of the dimples, even though the whole surface has been lowered too.
They can move around freely.

Sent from my XT1585 using Tapatalk

So a magnetic field will align copper electrons in the same direction and make them jump from dimple to dimple?


And, in theory all the energy is there...? just that a magnetic field of equal energy knocks the electrons off and the jump... or is it that the energy is neutral and the magnetic field pushes the electrons much like a pump pushes water? This concept might need to be broken down a tad further for my limited understanding.

 

[GoldDigger]

Can you go more into DC offset? Is this like the DC competent when a breaker interrupts fault current we must take into consideration?



Any pics or links? Im confused...






How so when a generator is often a pure circle? The winnings will simply reflect this pure circle and in turn produce a sine wave that is the byproduct of a pure circle and this resembles a perfect sine wave. ?

A most excellent question
If the generator windings were perfectly flat coils that rotated in a uniform constant magnetic field you would get very close to a perfect sine wave.
Instead you have non flat coils and a non uniform magnetic field (produced by other coils.). Add in the effect of hysteresis in steel cores and you move away from the perfect circular function.
Power generators (POCO style) are designed to come very close to a sine wave.

Sent from my XT1585 using Tapatalk

 

[Ingenieur]

Flux density varies due to the geometry as pole pairs pass introducing distortion
it is very small compared to the fundemental