Project Overview
Project Type: Medium Voltage Distribution Network Upgrade & Expansion
Completion Date: November 2024
Location: Limassol, Cyprus
Client: Cyprus Distribution Network Operator (Local DSO)
Technical Solution
TSTYNICE delivered a comprehensive 11 kV MV distribution upgrade package, including 1 MVA oil-immersed transformers and SF6 gas-insulated Ring Main Units (RMUs), to enhance power supply capacity and reliability in an urban commercial district.
Equipment Supplied
RMUs: 11 kV, SF6 insulated, 630A, 25 kA, 4-panel (incoming-metering-transformer feeder-outgoing feeder)
Transformers: 1 MVA, 11 kV / 400-230 V, Dyn11, oil-immersed, ONAN cooling, low-loss design
Quantity: 8 sets of combined RMU + transformer units
Enclosure: Transformers pad-mounted outdoor; RMUs in stainless steel cabinets with IP67 rating
Key Features
Compact Design: RMU features fully sealed, maintenance-free design with small footprint for urban constrained spaces.
High Reliability: Transformer with DYN vector group effectively suppresses harmonics; RMU with fully shielded, touch-safe cable terminations ensures operational safety.
Smart Interface: RMU equipped with DTU for SCADA remote monitoring, fault indication, and auto-isolation.
Environmental Resilience: Equipment with C4 corrosion protection rating, suitable for coastal high-salinity and high-humidity conditions.
Local Compliance: Meets Cyprus EAC technical specifications and EN/IEC standards.
Project Execution
Delivery Timeline: 5 months (from design finalization to on-site commissioning)
Key Phases:
Network Analysis: Assisted client with load flow and short-circuit analysis to optimize equipment parameters.
Customized Manufacturing: Integrated design of RMU and transformer for interface compatibility and installation ease.
On-site Support: Provided installation supervision, commissioning services, and local technician training.
Testing & Verification: All equipment underwent full type testing prior to shipment, including transformer temperature-rise tests and RMU mechanical/electrical endurance tests.
Operational Results
Capacity Increase: Added 8 MVA of supply capacity to Limassol's growing commercial zone, supporting connection for over 500 commercial customers.
Reliability Improvement: Ring network configuration enables N-1 supply redundancy, estimated to reduce SAIDI by 40%.
Loss Reduction: New low-loss transformers expected to decrease total network losses by 3-5%.
O&M Simplification: Remote monitoring functionality reduces average fault location and restoration time by 60%.
