Projects

power transmission and transformation
  • CLIENT

    Abroad

  • DATE

    April 16th ,2025

  • PROJECT TYPE

    power transmission

power transmission and transformation

The national grid upgrade project aims to build a high-reliability transmission network, integrate renewable energy generation and improve cross-regional power transmission capabilities. The project covers the construction of high-voltage transmission lines and the transformation of intelligent substations, and needs to adapt to complex geographical environments and diverse power grid standards.

Project scale and technical solution

1. High-voltage power transmission project

  • (1) Transmission type: 500kV AC (HVAC) and ±800kV DC (HVDC) hybrid system.


  • (2) Line design:

    • Cross-mountainous lines: Use high towers (tower height 80-120 meters) and helicopters to deploy guide ropes to reduce vegetation damage.

    • Coastal lines: Composite crossarm anti-salt spray design, insulator creepage distance ≥31mm/kV.

  • (3) Key equipment:

    • DC converter valve: IGBT-based modular multilevel converter (MMC), loss ≤ 0.8%.

    • Smart conductor: Carbon fiber composite core conductor (ACCC), current carrying capacity increased by 30%, sag reduced by 20%.

2. Intelligent substation transformation

  • (1) Main device upgrade:

    • 750kV GIS: Integrated intelligent monitoring unit (partial discharge, SF6 gas density online monitoring).

    • Transformer: On-load voltage regulation (OLTC) intelligent transformer, supporting bidirectional power flow (adapting to the reverse transmission of new energy).

  • (2) Digital system:

    • Digital Twin Platform: Real-time simulation of power grid faults (such as short circuits, harmonic oscillations) and preview of protection strategies.

    • Inspection Robot: Indoor track-type robot (infrared temperature measurement + ultrasonic partial discharge detection), replacing 90% of manual inspections.

Core Challenges and Solutions

Challenge Innovative Solutions
Construction on complex terrainUAV 3D mapping + BIM modeling optimizes the path and reduces earthwork by 40%.
New energy grid-connected fluctuationsSynchronous condenser (300Mvar) is configured to provide inertia support, and the frequency response time is ≤50ms.
Multi-standard equipment compatibilityFlexible interconnection transformer (FIT) realizes seamless connection of different voltage levels (220kV/500kV).
Extreme climate resistanceSpray anti-icing paint (RTV-II) on outdoor equipment of substations, and add ice melting devices (DC short-circuit current ice melting) on transmission lines.

Implementation results and value

1.  Power transmission efficiency improvement:

    • The HVDC line has a transmission capacity of 8000MW and a loss of ≤3.5% (the traditional AC solution is about 7%).

    • The reliability of cross-regional power transmission reaches 99.99%, and the annual power outage time is <5 minutes.

2. Environmental and economic benefits:

    • Annually deliver 18 billion kWh of clean energy, replace 5.4 million tons of standard coal, and reduce CO₂ emissions by 14.5 million tons.

    • Modular substation construction shortens construction period by 40% and reduces life cycle cost by 25%.

3. Social benefits:

    • The proportion of local procurement (tower materials, cable accessories) exceeds 50%, creating more than 1,200 jobs.

    • Train 200 local operation and maintenance teams to achieve technology transfer and knowledge sharing.

Core service capabilities

1. Full chain technology coverage:

    • Design end: electromagnetic transient simulation (PSCAD/EMTDC), lightning intrusion wave analysis (ATP-EMTP).

    • Construction end: tension wire laying technology (to prevent wire wear), high-precision laser calibration (GIS installation error ≤1mm).

    • Operation and maintenance side: Wide area measurement system (WAMS) + blockchain technology to achieve fault tracing.

2. Compliance with international standards:

    • Meets IEC 62271 (high voltage switchgear), IEEE C37.234 (protection system) and other standards.

    • Passed the World Bank ESF (Environmental and Social Framework) assessment and completed the biodiversity compensation plan.

3. Localization support:

    • Regional spare parts center (48-hour emergency response), multi-language operation and maintenance manual and training system.

    • Adapt to local power grid dispatching protocols (such as IEC 60870-5-104, DNP3.0).

Technology Innovation and Future Expansion

  • Superconducting cable pilot: -196℃ liquid nitrogen cooling superconducting power transmission (loss close to zero), reserved interface compatible with future upgrades.

  • Hydrogen energy coupling: Electrolyzers are integrated in the substation to produce hydrogen using surplus electricity (efficiency ≥ 75%).

  • AI predictive maintenance: Machine learning analyzes equipment aging trends, and the accuracy of spare parts replacement prediction is ≥ 90%.