Infinite Voltage & Frequency in Power Grids: What's the Reason?

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Discussion Overview

The discussion revolves around the concepts of voltage and frequency in power grids, specifically addressing the claim that they can be considered infinite. Participants explore the implications of high voltage on power loss and seek to clarify the meaning of infinite frequency in this context.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant asserts that higher voltage reduces losses, suggesting that infinite voltage would minimize losses, but questions the reasoning behind infinite frequency.
  • Another participant counters that neither voltage nor frequency can be infinite, stating that AC transmission frequency aligns with distribution frequency and that the concept of infinity is fictional.
  • A participant suggests that the term "infinite grid" may have been misunderstood, indicating a possible confusion about the terminology used in power systems.
  • It is proposed that the concept of "short-circuit power" could be interpreted as infinite in certain calculations, although this is described as a conservative approximation.
  • Several participants express skepticism about the accuracy of the information provided by the original poster's professor, with some suggesting that the misunderstanding lies with the OP.
  • One participant introduces the concept of an "infinite bus," explaining that it is a theoretical construct used in power analysis to simplify calculations, maintaining constant voltage and frequency while supplying any current or power.

Areas of Agreement / Disagreement

Participants generally disagree on the interpretation of voltage and frequency as infinite, with some asserting that the original claim is based on misunderstanding. Multiple competing views exist regarding the terminology and theoretical constructs in power systems.

Contextual Notes

The discussion highlights potential confusion surrounding the terminology used in power systems, particularly the concept of an "infinite bus" and its application in load flow analysis. There are unresolved assumptions about the definitions and implications of infinite voltage and frequency.

ranju
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I have got to know that the voltage and frequency of the supply in the power grids is kept as infinity.>! But what is the reason behind it..??
Well for the voltage to be infinity , I have studied that losses are inversely proportional to square of supply voltage ..so higher is the voltage , lesser will be the losses..!
But what is the reason behind infinite frequency..please explain.>!
 
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Neither voltage nor frequency are ever infinite or maintained at infinity. AC Transmission frequency is the same as distribution frequency. Voltage may be much higher, but infinity is a fiction.
 
I think that you might have heard the phrase, an infinite grid, and don't understand what it means.
 
ranju said:
I have got to know that the voltage and frequency of the supply in the power grids is kept as infinity.>! But what is the reason behind it..??
Well for the voltage to be infinity , I have studied that losses are inversely proportional to square of supply voltage ..so higher is the voltage , lesser will be the losses..!
But what is the reason behind infinite frequency..please explain.>!

As has been pointed out, you seem to have some confusion on how AC power is distributed. Can you post links to the reading that you have been doing that is causing these questions?
 
In my opinion what you heard –may be-it is that short-circuit power of a grid could be considered infinity if you calculate short-circuit current down stream a transformer. It will be a little bit conservative but for a rough appreciation it is ok. As already it is written in above posts the system frequency and the voltage would stay as rated.
 
Bu this is what told to us by our prof. !
 
Then he be wrong. I was once told by someone who should have known better that the reason the load was placed in the collector on grounded emitter BJT switch circuits (relay coil, LED, etc.) was because the collector typically has more heat sink area. Just because they should know does not mean they do know.
 
Or he be right and the OP misheard...
 
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OP misunderstood -I think. We be callin' the grid the infinite machine or the infinite grid (even though it is not).
 
  • #10
I think the OP misheard slightly. In power analysis, it is common to use the concept of an infinite bus.

An infinite bus is one that will maintain constant magnitude, phase, and frequency of voltage, while supplying any current or any power. It is a simplifying concept, not something that we find in real life.

In "load flow" analysis where we calculate the voltages, current, and power flows for an entire power grid, it is necessary for one node in the network to be treated as an infinite bus.
 

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