Misalai da take zama matsala a tsarin kammala na kisan jirgin kuli na vakansu?
Sabuwar da aka fi sani wajen gane da dielectric withstand a cikin vacuum circuit breakers:
Takwacin darajar: Ya kamata a dogara shi daidai kafin a yi dielectric withstand test don bincika da haraji ko takwacin darajar.
Dielectric withstand tests na circuit breakers sun hada da power-frequency withstand voltage da lightning impulse withstand voltage. Wadannan tests suna da shirya su masu yawan phase-to-phase da pole-to-pole (karkashin vacuum interrupter) configurations.
Yana taimaka a yi insulation test na circuit breakers a kan switchgear cabinets. Idan a yi amfani da haka, abubuwa da ake fada maza suna bukatar insulating da shielding, musamman tare da heat-shrink tubing ko insulating sleeves. Don fixed-type circuit breakers, an yi testing a nan bayan a yi direct bolting ta test leads zuwa pole column terminals.
Don solid-insulated pole columns da vacuum interrupters, vacuum interrupter baki da shugaban shed (skirts) don samun zama ba. Vacuum interrupter ya kasance a cikin epoxy resin tare da silicone rubber, saboda haka, karamin fina-finan interrupter bai da shugabanci. Amma, flashover ya faru a kan karamin fina-finan solid-insulated pole column. Saboda haka, creepage distance daga karamin fina-finan zuwa karamin fina-finan solid-insulated pole column yana da kyau a tabbatar. Don pole-to-pole spacing da 210 mm, idan a cike diameter da contact arm ya haɗa 50 mm, creepage distance bai iya saukar 240 mm idan ba a yi shed ba.
Saboda ba a iya kafa contact arm da pole column terminal daidai, sheds a kan wannan yanayi suna da muhimmanci sosai. Don 40.5 kV applications, da pole-to-pole spacing da 325 mm, hakan ya fi shi a yi shed ba zai iya taimaka waɗanda suka neman. Saboda haka, ana buƙaci a yi amfani da compressed silicone rubber don kafa sealed solid insulation a kan joint da ke contact arm da pole column, don kafa surface tracking da ke karamin fina-finan pole column. Bayan wannan treatment, creepage distance daga karamin fina-finan zuwa karamin fina-finan via contact arm zai iya tabbatar, inda ake iya kawo discharge.
Idan external insulation clearance da creepage distance na solid-insulated pole column suka duba da yawa, discharge ba zai faru ba. Dielectric strength reduction yana faru ne saboda loss of vacuum a cikin interrupter ko complete failure na pole assembly. Cracks ko housing defects na gaba-gaban design ko manufacturing, early material aging saboda processing issues, ko vibration-induced flashover/breakdown zai iya taimaka da equipment damage.
Don insulation-cylinder-type pole columns, karamin fina-finan da karamin fina-finan na insulating cylinder suna buƙaci da creepage distance. Saboda haka, products da pole spacing da 205 mm ba suka daɗe ba. Kuma, vacuum interrupter baki da shugaban creepage distance da za su iya kafa flashover daga karamin fina-finan zuwa karamin fina-finan.
Kuma, hygroscopicity na material zai iya taimaka da insulation test failure. Idan epoxy resin ya da water resistance, exposure da tsari da take da ruwa ya iya taimaka da water molecules suka faru a cikin resin, wanda yake taimaka da hydrolysis da ya kasa chemical bonds da ya kawo performance—saboda adheesion da mechanical strength.
| Test Item | Unit | Test Method | Index Value | |
| Color | / | Visual Inspection | As per specified color palette | |
| Appearance | / | Visual Inspection | Within limit | |
| Density | g/cm³ | GB1033 | 1.7-1.85 | |
| Water Absorption | % | JB3961 | ≤0.15 | |
| Shrinkage | % | JB3961 | 0.1-0.2 | |
| Impact Strength | JK/m² | GB1043 | ≥25 | |
| Bending Strength | Mpa | JB3961 | ≥100 | |
| Insulation Resistance | Normal State | Ω | GB10064 | ≥1.0×10¹³ |
| After Immersion for 24h | ≥1.0×10¹² | |||
| Electrical Strength | GB1408 | ≥12 | ||
| Arc Resistance | S | GB1411 | 180+ | |
| Comparative Tracking Index | / | GB4207 | ≥600 | |
| Flammability | / | GB11020 | FV0 | |
Ruwa yana da shugaban conduction da kula. Ba a yi absorption da ruwa, dielectric constant na epoxy resin yana ɗauki da insulation resistance yake ƙare, wanda yake taimaka da electrical leakage, breakdown, da wasu failures a kan electrical equipment. Epoxy resin da ya samu moisture a cikin circuit breaker pole columns zai iya taimaka da partial discharge, wanda yake ci gaba da tsarin equipment service life.
A kan high electric fields, moisture yana taimaka da growth na electrical trees, wanda yake ƙare da insulation performance. Wannan shine babban sababi na epoxy resin insulation failure a cikin power equipment.
Moisture absorption yana taimaka da reactions bayan epoxy resin da wasu environmental factors (kamar oxygen, acidic ko alkaline substances), wanda yake taimaka da material aging, wanda yake ci gaba da yellowing da embrittlement.
Don high-current solid-insulated pole columns, heat sinks suna da shugaban aiki a cikin upper part. Waɗannan heat sinks suna da aluminum da karamin fina-finan epoxy fluidized insulation. Saboda thin walls na heat sink fins, electric field intensity yana da yawa a top—even though rounded edges are provided—making discharge likely.
Gaskiya, discharge zai faru a kan heat sink da metal shutter. A lokacin wannan, ya kamata a taimaka da electrical clearance bayan su. Shutter ya kamata a koyar da sharp edges; instead, bent flat surfaces ko similar designs zai iya taimaka da electric field distribution.
Tambayar Da Yawanci
