Reactive Power Compensation Solution
Manufacturing Plant: A Plastic Company in Zhejiang
Case Introduction:The main loads of this company are air compressors and injection molding machines. Load characteristics: high starting current, large current fluctuation amplitude, high speed, and generation of harmonics.The capacitors in the power distribution room's capacitor bank resonated with the load, causing severe damage; The power factor fluctuated significantly during photovoltaic operation, averaging around 0.2; And there was severe three-phase imbalance, with the neutral wire overheating.
On-site Test Results:The capacitors in the power distribution room's capacitor bank resonated with the load, causing severe damage; The power factor fluctuated significantly during photovoltaic operation, averaging around 0.2; And there was severe three-phase imbalance, with the neutral wire overheating.
Solution:The modification involved removing the capacitors from the original capacitor bank and replacing them with an SVG static var generator.
Photos Of The Mitigation Equipment Installation:
Comparison Of Mitigation Data:
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Before mitigation: The three-phase current waveforms were distorted. |
After mitigation: The three-phase current waveform tends to be sinusoidal. |
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Before mitigation: Phase A 3rd harmonic current content: 34.83A Phase A 5th harmonic current content: 19.84A Phase A 7th harmonic current content: 12.18A Phase A 9th harmonic current content: 4.98A Phase A 11th harmonic current content: 3.82A
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After mitigation: Phase A 3rd harmonic current content 1.9A Phase A 5th harmonic current content 0.73A Phase A 7th harmonic current content 0.52A Phase A 9th harmonic current content 0.38A Phase A 11th harmonic current content 0.46A
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Before mitigation: N-phase fundamental current content: 53.78A N-phase 3rd harmonic current content: 99.59A N-phase 5th harmonic current content: 14.09A N-phase 9th harmonic current content: 16.49A
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After mitigation: N-phase fundamental current content: 13.26A N-phase 3rd harmonic current content: 3.79A N-phase 5th harmonic current content: 1.33A N-phase 9th harmonic current content: 1.92A
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Before mitigation: Phase A current was 330.63A Phase B current was 413.72A Phase C current was 409.74A Power factor was 0.9559
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After mitigation: Phase A current is 386.43A Phase B current is 391.63A Phase C current is 392.31A Power factor is 0.9991
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After mitigation, the three-phase current curves (A, B, and C) were highly integrated, indicating that the three phases were completely balanced and synchronized, and the N-phase current rapidly approached 0A. |
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After mitigation, the distortion rate of the three-phase current (A, B, and C) decreased rapidly and remained at around 1.5%. |
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After the correction, the power factor of the three phases ABC rapidly increased to 1 and remained at 1. |
Mitigation Result:
The power factor remains constant at 1 (PF=1).
Current distortion rate is less than 1.5% (THDi≤1.5%).
All three phases are perfectly balanced (almost no current in the neutral wire).