Work procedure
33 KV project with MPLS structure
RTU panel in the plant control room, IEC-104 over a BSNL or Airtel MPLS VPN to the SLDC.
Scope
What this project involves
A solar or wind plant evacuating power at 33 KV must report real-time generation data to the State Load Despatch Centre. In the MPLS structure, an RTU panel in the plant control room acquires the data and delivers it in IEC 60870-5-104 protocol over a BSNL or Airtel MPLS VPN circuit to the SLDC SCADA.
Typical application
- Solar and wind plants connected to the grid at 33 KV
- No utility PLCC or fibre path available from the plant
- An ISP can deliver an MPLS circuit to site — wired or RF last mile
System architecture
Procedure
8 stages, survey to handover
- 01
Site survey & data collection
STEL- Study the plant single line diagram, the 33 KV evacuation feeder and the connecting substation.
- Confirm control-room space, DC supply (station battery / UPS) and earthing for the RTU panel.
- List meters and transducers with CT / PT ratios; confirm Modbus availability on the MFMs.
- Check MPLS feasibility at site with BSNL / Airtel — wired or RF last mile.
Survey report Preliminary BOQ - 02
Point list & scheme approval
STEL + SLDC- Prepare the signal list in the SLDC format — MW, MVAR, kV, Hz, feeder currents, breaker and isolator status, energy.
- Prepare the RTU scheme and communication drawing.
- Submit to SLDC / TRANSCO and obtain approval.
- Obtain IP addressing and IEC-104 parameters (common address, IOA map) from the SLDC.
Approved point list Scheme drawing IP plan - 03
MPLS VPN circuit provisioning
STEL + ISP- Apply for the MPLS VPN circuit between plant and SLDC — as empanelled BSNL system integrator for AP & TS circles.
- Arrange the last mile to the plant — copper, fibre or RF link.
- Install the router / CPE and complete the circuit acceptance test.
- Verify VPN reachability to the SLDC front-end.
Circuit ID Acceptance test report - 04
RTU panel engineering & FAT
STEL- Panel GA and wiring drawings; RTU (Schneider MiCOM C264C / Siemens / Synergy) with DI / DO cards.
- Modbus interface to the MFMs, GPS time synchronisation, SMPS / DC-DC supply and MCBs.
- Panel assembly and factory acceptance test (FAT) before dispatch.
FAT report Panel drawings - 05
Installation at site
STEL- Erect and earth the RTU panel in the control room.
- Lay and terminate control cables (status / commands), CT / PT to meters and transducers, and the RS485 bus — ferruled and dressed.
- Connect the DC supply; place and patch the router.
Installation checklist Cable schedule - 06
RTU configuration
STEL- IEC 60870-5-104 slave configuration — IP address, TCP port 2404, common address and IOA map as per the approved point list.
- Modbus master polling of the MFMs; scaling and deadbands.
- Time synchronisation (GPS / SNTP) and event logging.
RTU configuration backup - 07
Point-to-point & end-to-end testing
STEL + SLDC- Point-to-point test of every signal, from field device to RTU.
- End-to-end test with the SLDC over MPLS — every IOA checked on the SLDC SCADA display.
- Compare MW / MVAR on the meter and at the SLDC; verify scaling.
- Link failure and reconnection test.
Point-to-point test report End-to-end test report - 08
Commissioning & handover
STEL + SLDC + Client- Joint commissioning with SLDC engineers and SLDC confirmation of data availability.
- As-built drawings, final point list, O&M manual and operator training.
- Annual Maintenance Contract.
Commissioning report Handover dossier
Testing & commissioning checklist
- Insulation resistance of control cables before energising
- Panel earthing continuity
- DC supply polarity and voltage at the RTU
- Every digital input operated from the field and seen at the RTU and at the SLDC
- Analog values compared with the meter display at different load levels
- Time-stamp accuracy against GPS
- IEC-104 connection re-established after a link or power interruption
Documents handed over
- Approved point list and IOA map
- RTU scheme and communication drawings
- Panel GA and wiring drawings (as built)
- FAT, point-to-point and end-to-end test reports
- RTU configuration backup
- MPLS circuit details and ISP escalation contacts
- O&M manual and training record
Reference projects
Delivered by STEL
17 plants integrated to the SLDC over MPLS VPN circuits:
- Bhagyanagar India Limited, Munipally5 MW SolarAirtel MPLS VPN TS SLDC
- RMR Solar Energy Pvt. Ltd.1 MW SolarAirtel MPLS VPN TS SLDC
- MLR Industries Private Limited2 MW SolarBSNL MPLS VPN TS SLDC
- MSR Mega Bio Power Limited7.5 MW SolarBSNL MPLS VPN TS SLDC
- Hyderabad Chemical Products Private Limited1.5 MW SolarBSNL MPLS VPN TS SLDC
- Peritus Corporation Private Limited2 MW SolarBSNL MPLS VPN TS SLDC
- Tropical Flavours Pvt. Ltd.1 MW SolarBSNL MPLS VPN TS SLDC
- Valens Molecules Pvt. Ltd.1 MW SolarBSNL MPLS VPN TS SLDC
- Heritage Foods Ltd.2.34 MW SolarBSNL MPLS VPN TS SLDC
- Hetero Labs Pvt. Ltd.4 MW SolarBSNL MPLS VPN TS SLDC
- Pragathi Group9 MW SolarBSNL MPLS VPN TS SLDC
- Prashanth Narayan G (PNG Solar Power Plant, Sirgapoor)7 MW SolarBSNL MPLS VPN TS SLDC
- M/s. Srinivasa Green Energies Private Limited2 MW SolarBSNL MPLS VPN TS SLDC
- VCarve Renewable Energy Pvt. Ltd.3 MW SolarMPLS VPN TS SLDC
- Hyderabad Institute of Oncology Pvt. Ltd., Khammam1 MW SolarBSNL MPLS VPN TS SLDC
- Dartyens Power Pvt. Ltd.1 MW SolarAirtel MPLS VPN TS SLDC, Vidyutsoudha
- Photon Energy5.5 MW SolarAirtel MPLS VPN TS SLDC, Vidyutsoudha
Next: 132 KV project with OPGW
Main & standby RTUs, PDH MUX and OPGW fibre on the 132 KV line — data, tele-protection and voice.