You need to read my posts. I never said anything about unbalance voltage. Faults, yes.
Poor idiot can't even read.
Your real hangup is with the term "force". The trouble is you have to use the whole term for emf, and that defines a voltage only. I suggest you read up on Faradays Law. You will find that the emf is generated on any wire moving through a field, even a wire with no connections on the end. How is this possible? Easy, the emf is a voltage, you are generating a voltage. No current need be involved. This is a freshman EE experiment.
I've got a news flash for you. This clown (Phil)is a moron, or is it maroon :-]! Comparing him to an electrician, even a substandard one, is an insult!
I've watched this thread from afar, and I'm beginning to doubt my earlier impression of your being a rather bright and competent engineer. Arguing with this moron is a losing battle, and your wasting your time. Even when you, and others, have invested time and energy trying to enlighten him it was a waste. It's a lot like watching a clown (Phil) throw crap at his image in a mirror. Just being in the vicinity will likely get you splattered with the rebound, even if you are a nonparticipant!
Arguing with him will almost certainly dumb you down. There's such a vacuum between his ears that anyone coming close is likely to lose brain matter in the process.
There could be an upside to this fellow. If you need a golf ball sucked through a garden hose you could just place the other end in his mouth, and stand back. Not impressed? How about the fact that while sucking the golf ball through the hose he's simultaneously drawing 20" of vacuum on the nearby chainlink fence!
Nothing really. Most electricians know what they are doing and know the limits of what they can do. Just as I know there is no way I can bend conduit, so I leave that up to the electricians.
I have run into some that were quite scary with their almost supersitious beliefs in oddball electrical practices. I have been called in to troubleshoot in plants where the electrician has installed all kinds of "sprecial" grounds to help the control system work better. Talk about fun; trying to convince him that he was doing it all wrong. And then the electrician who just simply would NOT believe that the meters on all houses measure kWh with the same accuracy (within the accuracy range of course). He swore that newer homes got "faster" meters. Good grief. And believe it or not, I have run into several electricians who believe all of the "free energy from the vacuum" crap. They were convinced utilities were holding back the progress in that area and that anyone who didn't agree was part of the conspiracy!
So, I have had some interesting encounters with electricians that thought they knew more than they did.
At this point I am surprised Phil can remember to breath by himself.
EMF = electro magnetic force, or electro-motive force? Has something being assumed changed in this pedantic discussion? Do any of you use of know about Maxwell's equations with respect to all this? Just curious.
Not to take sides or cause conflict, but would you (or Mr. Scott) please explain the dynamics of back emf as you see it. That is, its cause and effect on motor operation and the same on the energy source supplying the motor? Also is it a voltage, current, or force?
This is rich!!! You pick the two smartest guys in the electrical engineering group (Don & Charles), that have probably over 75 years experience between them designing electrical machinery and power systems, and call them idiots. They (and I) have studied and worked with utility grid systems for years and are members of the industry that you're trying to claim has known about "back emf affecting power grids".
Then you hang your whole argument on an antiquated term (back emf, although we used to call it 'counter emf' in my 'neck of the woods') as 'proof' of your arguments.
And just for the record, you can have a force without motion (stand on a scale to weigh yourself and don't move). Similarly, the force on a charged particle in an electric field is independent of its mass (try explaining
*that* with F=M*A ). And the force on the electrons in a conductor moving in a magnetic field is independent of the electron mass (scalar product of field strength and velocity of charged particle).
The 'forces' on the charges in a conductor moving through a field do *not* necessarily cause motion. In fact, in a motor, the forces on the charges in the moving conductor actually impede their movement. Without these forces impeding motion, the applied voltage (from an external source) would cause much more current.
A simple proof of this is a simple generator with no load connected. You have electrons in the conductor moving normal to a magnetic field. A simple way of looking at it is all the electrons have a 'force' exerted on them and this develops the terminal voltage. But the electrons don't move because there is no external circuit. In beginning texts, the movement of the conductor in the magnetic field generates an 'emf'. No current flow, just a voltage/emf.
As I requested from Mr. Kelly or Scott, would you please explain the dynamics of back emf as you see it. That is, its cause and effect on motor operation and the same on the energy source supplying the motor? Also is it a voltage, current, or force? I have seen conflicting explanations here and there, and I figure you guys likely know the score. :-) TIA
If you take two half wits and multiply them you do not get unity.... but 0.25....even if you add two half wits you dont get unity even though the math could be seen as correct..... Claiming PhD status just makes it worse. It also wouldnt be the first time ive seen the less utterly brilliant working for a power company.
You are asserting that a corporate postion implies competence? I dont think you are actually...but thats how it comes off.
On the voltage/ force issue... those are similar but not identical... that is the root of our little disagreement here. ...Force = Mass x Acceleration.., forever ... in physics..and the study of electricity and its current is part of physics....
Taking the mass out of it as you have in some of your examples ...say for instance a generator not connected to a circuit indeed leaves voltage live and mass static...but its still mass.. the electrons availabe to move.. the force remains potential.
A large motor generatiing back emf .. would generate more of that in terms of voltage and amperage than a smaller motor obviously.... so this EMF term does have a variable other then voltage...thats quite obvious in this example... or all EMF would be the same in magnitude..and it isnt.
A large motor, say 1000 hp is going to kick back 100.000 times the net force (EMF), as a say a tiny 1/100 hp motor... that should be implicity obvious. Is it obvious to you?
Do I need to prove that... ?
the *voltage of the emf will be the same under the same conditions of course... but the net EMF... with the force term used, will of course be dramatically greater with the huge motor...roughly 100,000 times greater with the larger motor.
That of course is because of the huge mass differences between the two motors.
obviously then, not a straight Voltage =emf issue. emf more closely relates to power when in motion..than merely the voltage applied. Voltage remains constant regardless of any motion or not...but the force varies... thus the term EMF.
I think thats a fairly concise argument.
I have used the term counter EMF in the past also... but do not equate it to 'back EMF' as you do... back EMF evolved I believe to more clearly describe emf coming back out onto the grid, slightly out of phase with incoming current.. and at a different amplide, somewhat as AM and FM radio waves modulate amplitude or frequency.... yet the same signal being carried on a single antena.
As these emf influences leak back onto the power grid, they create or constitute in themselves distortions in the electro magnetic effects, reducing the efficiency of any connected motors, designed of course to operate on clean power.
Some of the errors here are semantic in derivation...some a result of EE's apparently who were not paying attention in thier physics 1a and subsequent courses.
you're trying to
I invite you then to review your materials on issues related to some large industrial power users and their empact on the quality of the power in the rest of the grid.. especially customers farther from the generating source than the industrial user in question.
(back emf, although
as 'proof' of
It should be obvious to you by now that is not the case.
That was my typo- I thought that I had caught and corrected it befor sending -Yes - it does mean "electromotive force" Please accept my apologies. Yes, I do know Maxwell's equations with respect to this (more convenient to use the integral form when dealing with magnetic circuits as in machines).
Basically EMF or "Electromotive force" is a term which appeared in the late half of the 1800's to describe a potential difference (voltage) as the "force" causing a current to flow (N.B. Electrons weren't known at the time) It is an anachronistic term which has led to many misconceptions.
"Back EMF" is a term that originated with early DC machines to describe the speed dependent voltage that was generated by the motor stator conductors moving in a magnetic field. This generated voltage opposes the applied voltage (it damn well better says "conservation of energy" ). In terms of power the mechanical power developed is given by Pmech=Torque*angular velocity which is the same as current*(back emf). At no load, ignoring losses, the speed of the motor is such that the back emf =the applied voltage and the current in is 0 --ditto with the power.
If a mechanical load is applied to the motor, it slows down and the back or generated emf drops. Then the supply voltage exceeds the back emf and a current is produced so that torque (depending on current) is developed and power is transferred to the mechanical side. Back emf is simply a speed voltage that is generated. Note that there is no difference between a motor or a generator except in the way that the power flows. Try to drive a DC motor to a higher speed will result in an increase in the generated voltage and, if it exceeds the supply voltage- a reversal of power flow so the machine will generate.
In an AC synchronous machine- this back emf can be varied in magnitude and the phase of this voltage with respect to the supply determines the power transfer. A synchronous machine can only run, in steady state, at a speed determined by the frequency. If the load on a motor is increased, the "back emf" drops back in phase and power flows. If the back emf is greater (magnitude) than the applied voltage- the motor is overexcited and will be capacitive. If underexcited, it will appear inductive. However, here, the term "back emf" is rarely , if ever used- excitation voltage may be used as normal operation is at one speed so the field is the controlling variable.
Most motors are AC induction motors. These get their excitation from the supply. It is somewhat harder to identify the "back emf" and it is generally not worth while bothering to do so(In writing the general set of differential equations for an induction motor there are speed voltage terms but the usual steady state model is that of a transformer-hey- it works). An induction motor can be used as a generator if it gets excitation (magnetisation) from the system or from some other source such as capacitor banks. Note that -in any machine- if the back emf is 0- then there is no power transfer taking place-In practice this is at 0 speed and current will generally be highest in this condition. Lots of torque but no power.
Dear Don, to avoid getting all pissy over this little disparity in insight I snipped your no doubt superbly well stated position and am posting this tidbit I found by accident while responding in another thread re the vars issues.
This is about harmonic distortions and the broader power grid from EC and M's ezine.... maybe you can forward it to Charlie and his pal who have been trying to hose me with thier EE and PE certs. Charlie had given up on me entirely.. he will find this article enlightening, and from a top level source.
My remarks from another thread:
snipped
Beyond that there are harmonic distortions that any large facility can feed back into the power grid, screwing things up... the utility companies just hate that....motors and transformers can both create unwanted harmonic effects.
Paragraph 2 of the following article addresses these harmonics and power grid issues
formatting link
"However, just providing the raw power isn't enough these days. Motor drives present a nonlinear load to the power grid feeding them. Characteristically the diodes in an inverter's input stage create harmonic distortion as they switch on and off. Reflected back into the line, these harmonics tend to sap usable power and cause overload in transformer neutrals, circuit breakers, and motors. They can even damage other sensitive equipment connected to the same source. Some industry estimates predict that harmonics will eventually consume up to 50% of the energy on the nationwide power grid-clearly anunacceptable situation.
The solution, of course, is to suppress harmonics."
I fully agree with Charles and Don's explanations. 'back emf' is a voltage developed in a motor by virtue of the rotor conductors moving in a magnetic field. It opposes the applied voltage and limits current flow (but not create a current flow of its own, except in the rare situation of a transient fault on the supply). In simple DC machines, it is easy to understand, but it also exists in AC machinery.
Its only effects on the power source is to oppose the applied voltage and reduce the current flow. *IF* the applied voltage is rich in harmonics, the 'back emf' can be affected because said harmonics can distort the magnetic fields. As such, significant currents at the harmonic frequencies can thus flow from the source of the harmonics. These currents can cause excessive heating. But the currents come from the source of the harmonics, not necessarily the utility source.
Hahahaha. Notice it says motor drives?! Motor drives are power electronic devices between the motor and the utility. Of course drives produce harmonics. The convert the AC input to a DC voltage and then invert the power back to a pulse width modulated voltage that approximates AC (at least most AC drives are PWM). The front end of the drive can be as simple as a diode bridge, or use SCRs, or even IGBTs. You can load the front end of the drive with a resistor on the DC bus and guess what? You get harmonics on the AC system. Most AC drives are 6 pulse devices and you get primarily 5th and 7th harmonics. It is not uncommon for very large (thousands of horsepower) drives to be 12pulse. This requires a phase shifting transformer to basically create 6 phase AC that is then rectified. The characteristic harmonics for a 12 pulse are 11th and 12th.
This is a good overview of motor drives. It has a small section on harmonics that they call "power line pollution". It will help you quite a bit. I am surprised in all of your years of experience you have never seen a motor drive or understand how they differ from a directly connected motor. I guess you learn something new every day.
formatting link
Here is good one about the harmonics from a drive. Watch the wrap in the link. You may have to cut and paste it into your browser:
They have provided references to several university level texts, they have a particularly high level of education in the arena of electrical machinery and power systems. And their explanations are in align with many references found in university level texts and on-line web references. Your theory, however is *not* supported by the few web links you've given, is *not* found in any university text and does *not* fit the observable facts.
You have claimed that your explanations are 'well known in the industry'. But people like Charles, Don and myself are members of that industry. And have each of us been in that industry for many years. We have separately worked in the field of power systems and large scale electrical machinery for quite some time, yet we haven't heard of it. You may claim we're ignorant, but if we haven't heard of it, so much for your assertion that 'it is well known in the industry.'
Force = mass x acceleration is the physics of how a force interacts with any mass. It explains how a net force on a given mass will accelerate it. If a given mass is observed to be accelerating, the formula can be used to calculate what net force must be acting on it.
But it is *NOT* the only definitive explanation of 'force'. It *has* been used as the definition of mass, which is also an interesting definition of inertia.
Force = K * X where K is a constant for a linear spring and X is the spring displacement from its 'rest position' Hmmm, no 'mass' in this equation. Do compressed springs not exert a force?? And don't go claiming that a massive spring exerts more force than a small one. It can easily be demonstrated that the force exerted is not always dependent on the mass of the spring.
Force = K * m1 *m2 / r^2 where K is the universal gravitational constant, m1 and m2 are the masses of two bodies and r is the distance between the bodies. True, we have *two* masses here, but no acceleration term at all.
Force = K * c1 *c2 / r^2 where K is the faraday constant, c1 and c2 are the net charges of two bodies and r is the distance between the charges. No masses here. True, the fundamental unit of charge (so far in physics) is found on an electron (that has a mass). But the amount of force exerted by this is a function of the
*charge*. The electrostatic force on two different amounts of masses can be the same if the *charge* on the two masses is the same.
Force = K * c * E where E is the electric field strength acting on a unit charge. Again, the force is a function on the amount of *charge* on the object, not the mass of the object.
Force = K * B X V where K is another constant, B is the magnetic field strength and V is the velocity of a unit charge moving through the field. Here we must be careful to use the 'cross product' of the two vectors.
Interestingly, the international definition of the fundamental unit of Ampere uses 'force' in its definition.... "The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 x 10-7 newton per meter of length."
This is the one electrical quantity that is in the SI base units. From this and the other base units, the derived SI units for electrical power, voltage, magnetic field and many others are derived.
Actually, a 1 hp motor, or a 100 hp motor generate almost the same amount of 'back emf' when running unloaded. They both generate 'back emf' that is
*almost* equal to the line voltage applied ('almost' because they both have losses). And since 'back emf' is a voltage, *not* a current (as so many folks have tried repeatedly to explain to you), it is pretty much independent of motor size if the applied voltage is the same.
And because the premise of your statement is flawed, (that larger motors generate more 'back emf' than smaller ones), the rest of your conclusion is flawed as well.
No. A 1000 hp motor designed to run on a 4160V line, running unloaded, will be generating an internal voltage very close to 4160V. Similarly, a 1 hp motor designed to run on a 4160V line running unloaded will be generating an internal voltage very, very close to 4160V. If what you say were true, the
1hp motor would be generating an internal voltage of only 4.160V. And if
*that* were true, what limits the current flow from the 4160V to 4.160V in the 1 hp case? Winding resistance? The winding resistance of such a motor would be much less than 1 ohm, so Ohm's law would indicate the 1hp motor draws 1000 times the current of the 1000 hp motor when they both run unloaded. Isn't it obvious that that isn't true?
You keep trying to separate the 'EMF' from 'voltage'. The term 'EMF' is an achronism for voltage.
If you keep insisting that F=M*A is the only formula for a force and EMF is dependent on mass, then how do you explain the operation of a DC machine where the current is constant and there is no acceleration? By *your* notions, the force in a DC machine is zero, regardless of its mass since the current flow is constant and there is no acceleration. Let me guess, because the rotor is spinning, all the electrons on the rotor are undergoing acceleration??? That's a non-starter, it implies a large diameter rotor with the same mass rotating the same speed as a smaller diameter rotor generates a different amount of 'back emf'.
Again, you keep coming up with some vague idea/definition of what 'emf' is, when the rest of the world use to use the term for voltage. The rest of the world agrees that 'emf' is an antiquated term for a voltage created by electromagnetics. Yet you keep insisting it is F=M*A.
So far, you've said that this 'back emf' is a function of 1)machine mass, 2) rotor speed, 3)hp rating. Have I left anything out, or is there some more variables you want to throw in?
I don't. Study the equivalent circuit of a DC machine and you will find an internal *voltage* generated that is proportional to field strength and rotor speed. It is not described as a 'force' except in antiquated texts.
Funny, I've seen the voltage at the terminals of many an AC motor on an oscilloscope and never seen such 'emf coming back out onto the grid'. (voltages measured line-line, line-neutral and current waveforms measured by the voltage drop they create through precision resistors) I have seen distortions in the supply voltage, but they only exist when a non-linear load is connected. The distortions in voltage are easily explained by the resistance/reactances of the supply and the non-linear currents caused by non-linear loads. Power supplies with much lower impedances tend to have much cleaner voltage waveforms than those with higher impedances.
Utilities *do* get concerned when one customer has severely non-linear loads. Such a customer's severe high-harmonic *currents* cause high harmonic voltage disturbances due to the utility equipment's resistance/reactance. And if not controlled, the *voltage* disturbances will affect other customers, whom the utility is obligated to supply power to within the standards. Most utilities can compell such a customer to correct the problem themselves, or charge them for having the utility correct the problem so as not to affect other customers.
But this just doesn't happen with induction motors. In fact, *large* induction motors, with many slotted windings draw almost perfect sinusoidal currents and thus cause little or no voltage distortions in the utility equipment's resistance/reactances.
But *your* theories would dictate that *large* induction motors generate
*more* of your mysterious 'emf' (it is clear now that your use of the term is unique and *not* in compliance with any industry practice). So *large* motors, because they have more mass, should generate more 'back emf' and distort the grid voltage more? Yet experimental data, seen everyday doesn't support that position. Large motors cause more of a voltage disturbance ,*when started*, but the disturbance quickly subsides as the motor reaches normal speed.
Simple fact is, voltage distortions on grid supplies are caused by distorted
*current* flow through utility equipment. The phenomenon can be fully analyzed using conventional circuit theory by replacing the ideal voltage source with a real one. Real world grid supply includes a variety of resistances and reactances, whose voltage drops are dependent on the currents flowing through them. I'm sure any university professor of power EE would be happy to explain it to you (as Charles and Don have already).
Been there, done that. 'large industrial power users' come in all 'shapes and sizes'. Arc furnaces (not induction or resistive ones, *arc*) are one of the worst. They are a heavy load that is non-linear. High non-linear currents cause non-linear voltage drops in utility equipment's resistance/reactances. On the other hand, pumping stations whose major loads are induction motors are pretty benign. Rolling mills are a bit of a mix. Although the loads are induction motors that do not create a lot of harmonic distortions, the loads are starting/stopping/reversing all the time. Depending on their equipment, the constant starting/stopping of the many motors cause periodic dips/surges in supply voltage. But these are with a period of several seconds, not harmonics of the supply frequency. If the rollers are controlled by solid-state drive (as many modern ones are), the *drive system* can draw a lot of non-linear currents from the supply. But if the drive is an older motor-generator setup to DC roller motors, the harmonic distortions on the line are nil (but you still have the surges caused by varying load).
Some customers have had problems when they installed versions of VVVF control on some of their machinery. Although the connected motors worked well because the VVVF drive has output capacitors, the VVVF drive's input stage (typically a phase controlled AC-DC converter) would draw highly non-linear currents from the supply. These currents would cause non-linear voltage drops in the utility supply equipment and thus the voltage supplied to other equipment is distorted. The severity of the problem is a combination of the severity of the distortions created by the phase controlled converter and the impedance of the supply. The 'fix' is to filter the input to the phase controlled converter such that the supply line 'sees' less of the non-linear currents.
To summarize, when a large customer draws a high amount of non-linear current from utility equipment, the resulting voltage drops created in that utility's equipment will also be distorted. And yes, that can affect other customers. But... 1) The distortion is easily analyzed by conventional circuit analysis of the load current and supply resistances and reactances.
2) Induction motors are some of the *least* offensive loads in this regard (electronic phase-controlled and arc-type loads are the worst). 3) The mass of a motor has nothing to do with the amount of internal voltage developed.
4) 'back emf' is an antiquated term used to describe the internal voltage developed in a spinning motor, nothing more (except in your very small little world of one).
And to return to the original point of this thread for a moment, neither voltage nor current distortions have any appreciable affect on the accuracy of the standard household kwh meter. Although a voltage imbalance between hot legs and the neutral can, as I recently learned from Dan Lanciani's discussion.
Here we see that the industry is talking about 'motor drives', not motors. Motor drives, with diodes and phase-controlled SCRs on their input stages are responsible for high amounts of non-linear currents drawn from the supply. Not the motors themselves. You have been arguing that motors themselves are the culprit and that is simply not the case (as we have repeatedly explained).
These non-linear currents create corresponding non-linear voltage drops in the supply equipment's resistance and reactances. Since the output voltage of supply transformers and transmission lines includes these distorted voltage drops, the output waveform supplied to all connected loads is affected. None of this has anything to do with the 'back emf' generated internally in a motor. You've just proved that power supply harmonics are caused by something besides motors themselves. It has been an increasing problem because of the increased use of electronics (both in motor drive systems and non-motor related loads).
Even a resistive heating element can be a problem, *IF* it is controlled by a phase-controlled proportional heating controller. No motor, no moving parts or appreciable magnetic fields, just a simple resistor element. But the controller for it, applying a phase-controlled voltage to the resistor results in distorted current waveforms that can affect the supply in the same way. Same problem, same cause, and no 'back emf'.
This article is yet another reference you claim supports your position that 'back emf' generated inside motors 'leaks out to the grid', when in fact it does nothing of the kind. It explains the problem of harmonics in supply voltage created by the type of load connected and that of electronics introducing a high amount of harmonic content on supply systems by virtue of their non-linear *current* waveforms.
Charlie you are spinning here... My original remarks were that harmonics generated by the user, from many different sources, including motors and transofomers fed back into the power grid...which you denied flatly. Then tried to assert your correctness on the basis that you had a job at a utility company.
Now we see in this report that you were dead wrong and not only that but harmonic feed backs threaten the grid to a 50% level...its a massive problem...and this article address ONE of the causes... now you say its invalid because it doesnt mention others............... charlie there are many causes of harmonic distortions that FEED BACK INTO THE GRID.
thats just how it is pal..... now what do you expect me to do...find a journal article for each type of harmonic distortion and the range of its proximate causes, types of equipment etc and then post those? When I find an article that mentions a GE motor what will you do? Claim that only GE motors create a problem and that of course I am wrong because the article doesnt mention westinghouse motors or sychnorous motors or shaded pole motors or motors painted light green?
Is that it charlie.... you think thats an impressive argument? You assert that no way do harminics feed back into the grid to produce unwanted results... then here we are with an article mentioning ONE source of the problem...a not so common motor drive..but says the grid is threatened to a 50% level and you think there are not utterly common and pervasive harmonic feed backs from nay sources into the grid?
Charlie.. you can do a whole lot better than that.
Here is the article again Charlie... read it. Notice the comment on the pervasiveness of the *problem... a problem that you have been asserting for 3 days that doesne even exist ...you have asserted that harmonic distortions created by a user are *not an issue in the power grid,,, and these do not feed back... and also that harmonic distortions are not emf.... or 'back emf'.... you have spun yourself into a deep hole Charlie.
It doesnt take a rocket scientist to see it either. This article is from a totally credible source...and its quite clear on the threat harminic distortions are to the grid... now what do you want me to do charlie...find an article that states water is wet or something? Or that harmonic distortions and EMF are associated terms?
You know charlie this article doesnt mention computer power supplies either...but I had mentioned them. Do you think many types of those do not create harmonics that can screw up the grid?
Think again pal... this article is no those issues and choses to mention one source only...there are dozens. and Charlie its obvious to anyone that understands the physics of the issues..
Keep digging yer hole pal.
This is about harmonic distortions and the broader power grid from EC and M's ezine....
Paragraph 2 of the following article addresses these harmonics and power grid issues
formatting link
"However, just providing the raw power isn't enough these days. Motor drives present a nonlinear load to the power grid feeding them. Characteristically the diodes in an inverter's input stage create harmonic distortion as they switch on and off. Reflected back into the line, these harmonics tend to sap usable power and cause overload in transformer neutrals, circuit breakers, and motors. They can even damage other sensitive equipment connected to the same source. Some industry estimates predict that harmonics will eventually consume up to 50% of the energy on the nationwide power grid-clearly anunacceptable situation.
The solution, of course, is to suppress harmonics."
Charlie and his PhD wavng friend are presenting fragments that only mention some aspects of the power grid and metering issues and are trying to assert that there are NO harmonic feed back into the grid issues. They are utterly and totally wrong...and now trying to trash me for simply stating an oposite view.
How does this reference grab you in that case...it states that harmonic distortions fed back into the grid are estimated to reach 50% levels soon and threaten the power supply. Denial and abuse and calling me an idiot or trying to deny the utterly obvious is not working. Harmonics from MANY sources and causes are feeding back into the power grid....its a huge problem as Ive been stating...and its common knowledge... both statements flatly denied by Charlie and his PhD waiving pal who claim to be experts in the field.
Sorry..these two have then tried to spin defenitions of emf and harmonics ... not impressive at all. Sorry. Harmonics are compreised of Electo Magnetic Forces//
amazing these two guys. What will be next from them... will they deny what they have typed earlier or just say they have killfiled me and dont speak to idiots.
None of that will fly. We have here two guys long on record asserting no harmonic feed backs of any consequence to the grid... denying the industry wide notice of this massive and fast growing problem from many sources as I have stated... including motors and power supplies for computers.. but not given as examples in this article...so now Charlie is trying to asert that this massive 50% threat only comes from a few electronic motor drives because thats the example they used?
Adhominem is not an argument. either. .. its and evasion of the issues... what will Charlie and his PhD waiving pal say in response to this report? amazing. Do they want one on computer power supplies too? Induction motors? Lighting transormers? When will these guys recognise this utterly massive and well known issue in thier own industry instead of tryging to spin that Im an idiot and presenting articles addressing only the vars issues or whatever.
***** This is about harmonic distortions and the broader power grid from EC and M's ezine....
Beyond that there are harmonic distortions that any large facility can feed back into the power grid, screwing things up... the utility companies just hate that....motors and transformers can both create unwanted harmonic effects.
Paragraph 2 of the following article addresses these harmonics and power grid issues
formatting link
"However, just providing the raw power isn't enough these days. Motor drives present a nonlinear load to the power grid feeding them. Characteristically the diodes in an inverter's input stage create harmonic distortion as they switch on and off. Reflected back into the line, these harmonics tend to sap usable power and cause overload in transformer neutrals, circuit breakers, and motors. They can even damage other sensitive equipment connected to the same source. Some industry estimates predict that harmonics will eventually consume up to 50% of the energy on the nationwide power grid-clearly anunacceptable situation.
The solution, of course, is to suppress harmonics."
How 'rich' is this bud? This article mentions ONE uncommon source of harmonic distortions that feed back into the grid..(harmonics of course ARE a form of electro magnetic force EFM.. also denied by our two genius friends)... there are many other causes of this harmonic distortin//// in agregate they are predicted to present a 50% waste of generated power... they are already a serious problem as Ive stated on grids serving industry for half a century. Computer power supplies seem to be the fastest growing source of such feedback although not used as an example in this article.
Come on now tell me? is this 'rich'....
This is about harmonic distortions and the broader power grid from EC and M's ezine....
Beyond that there are harmonic distortions that any large facility can feed back into the power grid, screwing things up... the utility companies just hate that....motors and transformers can both create unwanted harmonic effects.
Paragraph 2 of the following article addresses these harmonics and power grid issues
formatting link
"However, just providing the raw power isn't enough these days. Motor drives present a nonlinear load to the power grid feeding them. Characteristically the diodes in an inverter's input stage create harmonic distortion as they switch on and off. Reflected back into the line, these harmonics tend to sap usable power and cause overload in transformer neutrals, circuit breakers, and motors. They can even damage other sensitive equipment connected to the same source. Some industry estimates predict that harmonics will eventually consume up to 50% of the energy on the nationwide power grid-clearly anunacceptable situation.
The solution, of course, is to suppress harmonics."
long article balance at URL above
(back emf,
woods') as 'proof' of
EMF of course is a very very generic term... all negative harmonics, all phase power, *all current IS EMF. Harmonics are EMF. a dead short is EMF... the energizer bunny runs on EMF... Electro magnetic forces ... you see?
These guys trying to split off a generic generic description such as EMF from its more specific terms just ***boggle ones mind. Then they deny there is any harmonic distortion of significance feeding back into the grid?
amazin' ain't it? I suggest that you avoid stepping into this hole our two certificate waiving friends have dug for themselves.
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.