Parallel Resonance in Power System

Click For Summary
SUMMARY

The discussion centers on the effects of a parallel circuit resonant at the 7th harmonic in a power system with a passive filter designed to eliminate the 5th harmonic. It is established that the parallel circuit does not impede the flow of 7th harmonic currents, rendering it "invisible" at that frequency. Additionally, while the 5th harmonic is bypassed by a series circuit resonant at its frequency, fundamental currents and all other harmonic frequencies can still flow freely between points A and B.

PREREQUISITES
  • Understanding of harmonic frequencies in electrical systems
  • Knowledge of passive filters and their applications
  • Familiarity with resonance in electrical circuits
  • Basic principles of power system analysis
NEXT STEPS
  • Research the effects of parallel resonance on power quality
  • Learn about passive filter design and implementation
  • Explore harmonic analysis techniques in power systems
  • Study the behavior of series circuits at resonant frequencies
USEFUL FOR

Electrical engineers, power system analysts, and professionals involved in harmonic mitigation and power quality improvement will benefit from this discussion.

LagCompensator
Messages
24
Reaction score
1
Hi,
imagine we have the following circuit shown in the figure below. There are installed a passive filter to filter the 5th harmonic. Now, after installation this creates a parallel path with a generator connected, let's say that this parallel circuit has a resonance frequency at the 7th harmonic. Then it turns out that some load further away causes 7th harmonic currents to flow and thus exciting the parallel resonance circuit.

  1. Would this cause Z to go to infinity in theory assuming ideal components and thus stop the flow of 7th harmonic currents from A to B shown in the figure below?
  2. Would fundamental currents and other harmonic currents except for the 7th be able to flow between A and B?
parallel resonance.png
 

Attachments

  • parallel resonance.png
    parallel resonance.png
    10.9 KB · Views: 492
Engineering news on Phys.org
LagCompensator said:
Hi,
imagine we have the following circuit shown in the figure below. There are installed a passive filter to filter the 5th harmonic. Now, after installation this creates a parallel path with a generator connected, let's say that this parallel circuit has a resonance frequency at the 7th harmonic. Then it turns out that some load further away causes 7th harmonic currents to flow and thus exciting the parallel resonance circuit.

  1. Would this cause Z to go to infinity in theory assuming ideal components and thus stop the flow of 7th harmonic currents from A to B shown in the figure below?
  2. Would fundamental currents and other harmonic currents except for the 7th be able to flow between A and B?
View attachment 109704
1) If the line is shunted by a parallel circuit resonant at the 7th harmonic, it will not impede the flow of 7th harmonic currents in the line. It is invisible at this frequency.
2) The 5th harmonic will be bypassed by the parallel circuit resonant at its frequency but the fundamental and all other frequencies can freely pass between A and B.
 
  • Like
Likes   Reactions: LagCompensator
tech99 said:
1) If the line is shunted by a parallel circuit resonant at the 7th harmonic, it will not impede the flow of 7th harmonic currents in the line. It is invisible at this frequency.
2) The 5th harmonic will be bypassed by the parallel circuit resonant at its frequency but the fundamental and all other frequencies can freely pass between A and B.
Correction:
2) The 5th harmonic will be bypassed by the SERIES! circuit resonant at its frequency but the fundamental and all other frequencies can freely pass between A and B.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
2
Views
3K
Replies
2
Views
2K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 28 ·
Replies
28
Views
2K
  • · Replies 41 ·
2
Replies
41
Views
7K
  • · Replies 13 ·
Replies
13
Views
4K
  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 9 ·
Replies
9
Views
2K