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La détection des décharges partielles (DP) constitue une technologie clé pour surveiller l’état de l’isolation et alerter en cas de défauts affectant les équipements électriques.Voici plusieurs méthodes principales d’identification :
1. »Hear » Electrical Signals (Most Common):Measure Current Pulses: Use sensors on equipment ground wires or capacitors to detect high-frequency current pulses from PD (Standard method, accurate but often requires power-off).Measure Electromagnetic Waves: Use antennas (UHF sensors) to capture ultra-high-frequency radio waves emitted by PD (Ideal for online monitoring of metal-enclosed equipment like GIS/transformers, good noise immunity).Measure Surface Voltage: Scan equipment metal surfaces with a probe to detect transient earth voltages (TEV) induced by PD (Simple for live inspections, but prone to interference).
<span></span><br><strong><span style= »white-space-collapse: preserve; font-size: 20px; »>3. Changements chimiques détectables par l’odorat (recommandé pour les équipements remplis d’huile) :</span></strong>
Analyser les gaz dissous dans l’huile de transformateur. Les décharges partielles produisent des gaz caractéristiques. Déterminer la présence et le type de décharge par analyse chromatographique.
4. »See » Light (Limited Use):Use UV cameras to detect ultraviolet light from external corona discharge (e.g., on insulators) during live inspections.Internal PD is usually invisible.
Key Points:Professional instruments are essential: Senses alone cannot reliably identify or assess PD.Choose method based on scenario: Consider equipment type (transformer, switchgear, cable), power-on/off needs, and whether qualitative or quantitative data is required.Combine methods for reliability: Often use electrical + ultrasonic or other combinations to confirm findings.Safety first: Live detection MUST be done by trained professionals following safety protocols.Trends matter: Regular checks or online monitoring to track signal changes over time is more valuable than a single test.
En résumé :