Mga Essential nga Tipo Routine ug Site Acceptance Tests alang sa Modernong Eco-Friendly RMUs
1. Sistema ug mga Standard sa Type Test
Ang type testing nagpatunay sa rasonable nga disenyo ug kalambigitan sa eco-friendly insulated ring main units (RMUs), batasan sa IEC 62271-200 ug GB/T 3906, ug kinahanglan:
Kalambigitan sa Insulation: Para sa 12kV RMUs, ang power frequency withstand voltage mao ang 42kV (1 min) para sa main circuits ug 48kV para sa breakers. Ang lightning impulse withstand mao ang 75kV (12kV system) o 125kV (24kV system), ngadto sa 15 standard impulses (1.2/50μs) bawat polarity. Ang partial discharge kinahanglan ≤10pC sa 1.2× rated voltage—mas mahigpit kay sa SF₆ units tungod sa mas mababa nga insulation strength sa eco-gases (e.g., nitrogen, ~1/3 of SF₆). Kinahanglan usab ang gas insulation strength tests, kasama ang evaluation sa "hump phenomenon" sa nitrogen.
Mechanical Performance: Ang circuit breakers kinahanglan magdugay 5,000 operation cycles, isolators ≥2,000. Ang mechanical characteristics (timing, speed, synchronicity) gisukod. Ang internal arc testing nangangailigan sa pagdugay 20–50kA sa 0.1–1s, ngadto sa internal pressure ≤50kPa ug enclosure integrity maintained. Ang IP67-level protection gipagtungha pinaagi sa double EPDM seals ug stainless steel.
Environmental Adaptability: Ang temperature/humidity cycling (40°C/93%RH sa 56 days) limita ang insulation resistance drop sa ≤50%. Ang salt spray testing (IEC 60068-2-52) nangangailigan sa 500 hours ngadto sa corrosion <0.1μm/year. Ang high-altitude operation (1,000–1,800m) nangangailigan sa 5–15% derating per 1,000m. Ang seismic testing sa 0.5g sigurado sa structural integrity ug contact resistance fluctuation <3%.
2. Routine Tests ug Execution
Ang routine tests sigurado nga mosatisfy ang basic requirements ang bawat unit:
Main Circuit Resistance: Gisukod pinaagi sa DC voltage drop o bridge method; ang values kinahanglan compliant sa specifications ug differ ≤20% gikan sa type test results.
Power Frequency Withstand Voltage: 42kV (12kV system) gipasabot sa 1 second; walay breakdown o flashover. Ang auxiliary/control circuits gisubok sa 2kV/1min.
Sealing Test: Kritikal para sa gas-insulated units. Ang leakage rate ≤1×10⁻⁷ Pa·m³/s (IEC 62271-200), gipagtungha pinaagi sa 24-hour pressure monitoring o helium leak detection para sa mas taas nga precision.
Mechanical Operation: 5–10 operation cycles gisubok ang flexibility ug correct function sa mechanical interlocks ("five prevention" rules).
Visual ug Electrical Checks: Inspect appearance, coating, labels, fasteners, ug electrical connections. Ang solid-insulated units (e.g., epoxy-coated modules) nangangailigan og special attention sa insulation integrity (walay cracks o damage).
3. Site Acceptance ug Special Environmental Tests
Final verification human sa installation:
Insulation Resistance: >1,000MΩ (gisukod pinaagi sa megohmmeter). Kritikal para sa pagtumong sa moisture, contamination, o defects—espesyalmente importante para sa gas-insulated units sa humid environments.
Protection Function Test: Simulate overcurrent ug ground faults para sa pagtumong sa protection device response ug tripping reliability.
Temperature Rise Test: Sa rated current, busbar temperature rise ≤70K ug contact rise ≤80K (GB/T 3906). Crucial tungod sa poor heat dissipation sa eco-gases (thermal conductivity ~1/4 of SF₆).
Special Environmental Tests:
High Altitude: Derate withstand voltage (e.g., 42kV ×1.15 ≈48.3kV sa 1,800m).
High Humidity: Anti-condensation testing para sa pagtumong sa internal dryness.
Low Temperature: Operation tests sa -40°C para sa pagtumong sa reliable switching.
4. Gas System Specialized Tests
Key differentiator gikan sa SF₆-based units:
Sealing Test: Helium leak detection (human sa vacuuming ug helium injection) achieves 1×10⁻⁷ Pa·m³/s sensitivity. Pressure decay method gamit ang 24-hour monitoring.
Pressure-Insulation Relationship: Para sa nitrogen-insulated units (0.12–0.13MPa operating pressure), subok ang insulation performance sa reduced pressure (e.g., <90% rated) ug evaluate "hump phenomenon" under impulse voltage.
Gas Purity ug Humidity: Ang moisture sa dry air units kinahanglan <150ppm. Gamit ang dew point meters o humidity sensors para sa monitoring.
Gas Chamber Integrity: X-ray inspection para sa weld quality (walay pores/cracks), mechanical load tests para sa deformation resistance, ug long-term pressure monitoring para sa seal stability.
5. Thermal Stability ug Innovations
Critical tungod sa poor heat dissipation sa eco-gases (e.g., nitrogen):
Temperature Rise Test: Long-term operation sa rated current; measure busbar, contact, ug joint temperatures. Kinahanglan compliant sa GB/T 3906 limits (≤70K for busbars, ≤80K for contacts).
Short-Circuit Temperature Rise Test: Apply rated short-time current (e.g., 20kA/3s); verify temperature rise ug thermal distribution under compact designs.
Innovative Cooling Solutions:
Radiative Cooling Coatings: Reduce surface temperature by up to 30.9°C; durable ug corrosion-resistant.
Smart Cooling/Dehumidification: Fan ug dehumidifier systems reduce temperature by 40% ug humidity by 58%.
Design Improvements: Optimized ventilation ug high-thermal-conductivity insulation materials enhance overall heat dissipation.
