Harmonics: A Sign of Problem or Stability? Thinking of Models
In electrical engineering harmonics are just mathematical / artificial components which can help us to analyze and understand certain electrical phenomena. But is this the end of the story? I humbly submit there is more than that behind the scenes.
Harmonics may have indeed some much more profound meaning. They seem to be related and express the stability and order of the physical process that generates them. And for this simple analysis let us go back to ancient scientific models.
From antique Greece to the medieval times - circular / harmonic movements are related to the eternal stability of the Unmoved Mover. The idea of a desire, love or appetite of the physical reality to be closer to the Source - led them to think of perpetual motions - for which the most perfect figure was a circle and hence, harmonically built.
These spherical movements are the basis for planetary harmonics - carried “by love, by intellectual desire, never satisfied because they know they can never completely assimilate themselves to their object, and never frustrated because they continually do so to be the fullest extent which their nature admits or requires. Their existence is thus one of delight. The motions of the universe are to be conceived not as those of a machine or even an army, but rather as a dance, a festival, a symphony, a carnival, or all these in one. They are the unimpeded movement of the most perfect impulse towards the most perfect Object.”
Can this perspective be of any help for power engineering?
In electrical engineering, however, the thing is a little more complicated, but nevertheless, let us try.
When a quasi-perfect sinusoidal voltage source is disturbed by a non-linear excitation (resulting from an energy conversion process, for example) the resulting current can be visualized as a sum of harmonic components (a fundamental + higher frequencies – thanks to Fourier). And although the higher frequencies can be annoying to the electric grid they themselves maybe a sign of the stability of the energy conversion process.
Thus, using the medieval model, they can be seen as a symbol of the harmony within the physical energy conversion process and the desire of all higher frequency components to maintain closer to the original source, via integer multiples of its circular movements.
Perhaps one could go even further and explain resonance as the natural / self-ability in nature to maintain, within bounds, and for as long as possible, the energy available between physical elements, via the production of a harmonic exchange of energy.
Anyway, the ancient and medieval models are certainly scientifically outdated, but they can still delight us - - - few constructions of imagination have such integrated splendor, sobriety and coherence – and perhaps, sometimes, they can still help us to visualize certain things by giving us intuition insights that cannot be derived purely from mathematics.
Some may say this is totally irrelevant and too philosophical, religious and metaphorical and that modern physics is direct and objective - - - but what about the “curvature of space”? - - - - I accept it, but it sounds more like the old definition of God – “a circle whose center is everywhere and whose circumference is nowhere. “
Without parables and metaphorical language modern science cannot speak to the masses.
I hope no one will think that I am recommending a return to the medieval model to study electrical engineering :-) – I am only re-affirming that different models may reveal different aspects and all models should be respected (even when they are obsolete) and non-idolized.
Meanwhile, let us continue to unfold the physical reality of electrical engineering and create more detailed models for harmonic studies and the grid of the future, but let us not forget that “nature gives most of her evidence in answers to questions we ask her. Here, as in the courts, the character of the evidence depends on the shape of the examination, and a good cross-examiner [or power engineering researcher] can do wonders. He will not indeed elicit falsehoods from an honest witness. But, in relation to the total truth in the witness’ s mind, the structure of the examination is like a stencil. It determines how much of the total truth will appear and what pattern it will suggest.”
Harmonics can indeed be a sign of problem, but they also express a profound order - - - "The beauty of electricity - - - [is] that it is under law " said the great Michael Faraday.
Cheers,
Paulo
PS – Phrases under quotes are from The Discarded Image (CS Lewis)
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