وحدات الربط الحلقي (RMU) للتوزيع الثانوي: البنية وتكوينات CCF وأتمتة القياس عن بعد

وحدات RMU المدمجة المعزولة بالغاز (24 kV / 36 kV)، وتكوينات CCF وCCCF، ومفاتيح فصل الحمل الآلية، ومؤشرات مرور العطل (FPI)، ودمج القياس عن بعد IEC 60870-5-104.

1. Secondary Distribution Ring Main Unit (RMU) Functions

Ring Main Units provide compact medium-voltage protection and switching in underground distribution loops (ring networks) for compact transformer kiosks and commercial facilities.

2. Standard Functional Module Configurations

RMU Configuration CodeComposition of Functional BlocksTypical Application
CCF2 Cable Switches (C) + 1 Fuse-Switch (F)Compact kiosks up to 1250 kVA
CCV2 Cable Switches (C) + 1 Vacuum Circuit Breaker (V)Substation transformers > 1250 kVA
CCCF / CCCV3 Cable Ring Switches + 1 Transformer FeederRing branch nodes and meshed grids
CCCC4 Cable Load-Break SwitchesSectionalizing and bus-tie loop stations

3. Smart Grid Automation & Telecontrol Protocols

To enable automated Fault Location, Isolation, and Service Restoration (FLISR):

  • Directional Fault Passage Indicators (FPI): Detect phase-to-phase and earth fault current paths.
  • 24 VDC Motorized Mechanisms: Actuate switches in < 3 seconds via SCADA commands.
  • Protocol Support: IEC 60870-5-104 (Ethernet TCP/IP) and DNP3 Secure.

4. Hermetic Sealed Tank Reliability

Primary live busbars, switches, and disconnectors are enclosed inside a laser-welded stainless steel tank with IP65 ingress protection and >30-year gas tightness per IEC 62271-200.

*Reference: IEC 62271-200:2021; IEC 60870-5-104; IEEE Std C37.20.3.*