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Electrical Efficiency

Power Quality and Harmonics: From Measurement to Mitigation

Power quality concerns whether voltage, frequency and waveform remain within conditions that support correct equipment operation. Harmonics matter, but sags, swells, interruptions, flicker and phase imbalance should be evaluated in the same event record.

Published: 6 min readSTR Energy
1

Sources of harmonics

Variable-speed drives, UPS systems, rectifiers, LED drivers and switch-mode power supplies can draw non-linear current. Current harmonics can produce voltage distortion across network impedance and affect other equipment.

2

A sound measurement plan

Choose analyser location, current-transformer ratio, recording duration and event thresholds for the problem under study. Compare the affected equipment, point of common coupling and multiple operating conditions rather than relying on one short measurement at the main panel.

3

Find the cause before selecting a filter

Do not select passive or active filters before understanding spectrum, resonance and load variability. Cabling, grounding, transformer loading and capacitor-stage issues can create similar symptoms.

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