Parallel Resonance in Power System

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LagCompensator
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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?
Single-line diagram of a power line between points A and B with impedance Z(ω) marked; below the line, two dashed boxes show shunt branches of series inductors Lo and a tuned filter with inductor L and capacitor C, each to a circle symbol.
 
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  • Single-line circuit diagram of a power system bus with a generator branch of series inductors L0 and an harmonic filter branch with inductors L and capacitors C in parallel, each shown in dashed boxes.
    parallel resonance.png
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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.
 
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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.