These clauses define how the EPC Contractor interfaces with Serbian transmission and distribution operators, ensuring grid-code compliance and seamless integration of energy assets into the national power system.
1. Grid Studies & Approvals
Contractor shall perform and submit all mandatory analyses for operator approval, including:
-
Load flow
-
Short-circuit calculations
-
Harmonic analysis
-
Flicker & voltage stability
-
Protection coordination
-
Dynamic simulations (when required)
All studies must be reviewed and accepted by the relevant TSO (EMS) or DSO (EPS/EDB).
2. Grid-Code Compliance Requirements
The EPC Contractor must ensure full compliance with Serbian grid codes, including:
-
Frequency response capability
-
Voltage control (AVR, Q-control modes)
-
LVRT and HVRT performance
-
SCADA communication protocols
-
Reactive power capability and power-factor limits
Any deviation is treated as a performance defect under the EPC Contract.
3. SCADA & Telecommunication Interface
Contractor delivers a complete SCADA integration package with:
-
Interface to EMS/DSO systems
-
Redundant telecom links
-
IEC 60870-5-104 or IEC 61850 compatibility
-
Real-time control signals (open/close, limiters, setpoints)
-
GPS or IRIG-B time synchronization
-
Cybersecurity compliance per operator standards
Testing must be witnessed jointly by Clarion and the system operator.
4. Substation Integration Responsibilities
Contractor is responsible for design and supply of:
-
Power transformer(s)
-
HV/MV switchgear
-
Protection & control panels
-
Busbar configuration
-
CT/PT selection
-
Earthing and lightning protection
-
Relay coordination aligned with TSO/DSO settings
5. Grid-Connection Works & Responsibility Split
Clear allocation of duties:
Contractor
-
All works within project boundary
-
Cables, ductbanks, substation, SCADA integration
Operator (EMS/EPS/DSO)
-
External grid reinforcement
-
Grid capacity allocation
Employer
-
Permits, land access, grid-connection fees
6. Grid Acceptance Tests
Required tests include:
-
Synchronisation test
-
Protection trip checks
-
Metering accuracy
-
Power quality (PQ) measurements
-
Voltage and frequency response tests
Failure of any grid acceptance test = non-completion under the EPC Contract.
7. Consequences of Grid Delay
If grid readiness is delayed due to reasons outside EPC Contractor control:
-
Milestones may be adjusted
-
Contractor is not liable for DLDs
-
Clarion (Owner’s Engineer) will verify and document cause of delay
8. Performance Guarantees Linked to Grid
EPC guarantees must reflect grid-connected conditions, including:
-
Output at Point of Common Coupling (PCC)
-
Grid losses
-
Reactive-power requirements
-
Availability of grid-facing equipment (substation, transformer, breakers, protection)