Project Overview

The Ningxia-Hunan ±800kV Ultra High Voltage Direct Current (UHVDC) Transmission Line Project is a critical power infrastructure initiative designed to enhance long-distance electricity transmission from Ningxia to Hunan Province. This project plays a vital role in optimizing China’s west-to-east electricity transmission strategy, ensuring stable and efficient power supply to central and eastern regions while promoting clean energy utilization.

This UHVDC transmission line spans approximately 1,500 kilometers, making it one of the longest and most advanced HVDC transmission projects in the country. The project consists of:
• Multiple converter stations at sending and receiving ends for efficient DC-AC conversion.
• High-capacity DC transmission conductors designed for minimal power loss over long distances.
• Hundreds of transmission towers optimized for high-altitude, desert, and complex terrains.

The project significantly improves grid stability, transmission efficiency, and energy security, while reducing dependency on fossil fuel-based power generation in the receiving region.
Construction Plan & Execution

1. Route Survey & Planning

Given the massive scale of this project, detailed topographic, meteorological, and geological surveys were conducted to optimize the transmission route. The line passes through:
• Desert and arid regions in Ningxia, requiring advanced anti-corrosion coatings and sandstorm-resistant structures.
• Mountainous terrains in western China, where rock-anchor foundations and helicopter-assisted tower installation were used.
• Dense forest regions and urban zones in Hunan, where the route was optimized to minimize environmental and social impact.

Advanced GIS mapping technology and electromagnetic compatibility studies were used to minimize transmission losses and prevent electromagnetic interference with existing infrastructure.
2. Tower Foundations & Structural Engineering

Due to the vast geographical diversity, multiple foundation types were implemented to ensure tower stability:
• Rock-anchor foundations in mountainous areas to resist high winds and seismic activity.
• Deep pile foundations in sandy and loose-soil regions to prevent shifting.
• Concrete raft foundations in urban areas to reduce land disturbance.

For transmission towers, we utilized:
• Ultra-high-strength steel lattice towers, capable of supporting ±800kV voltage levels and handling extreme weather conditions.
• Anti-corrosion and anti-wind coatings to withstand the harsh desert climate and monsoon conditions.
• Aerodynamically designed towers to reduce wind resistance and mechanical stress.

Tower installation methods included aerial lifting with helicopters in mountainous regions and crane-assisted assembly in accessible areas.
3. Conductor Installation & Stringing

As one of the highest-capacity transmission projects in the world, the conductor installation process involved:
• Specialized high-performance conductors designed to reduce energy loss and improve efficiency.
• Tension stringing techniques to ensure precise conductor alignment and minimal sag.
• High-altitude insulation design to prevent flashover risks in areas with high humidity and pollution.

To enhance performance, high-voltage polymer insulators were used, offering superior electrical insulation and mechanical strength.
4. Converter Stations & Grid Integration

This UHVDC system includes converter stations at both the sending (Ningxia) and receiving (Hunan) ends to efficiently convert AC power to DC and vice versa. The stations incorporate:
• High-efficiency thyristor valves for precise voltage and power flow control.
• State-of-the-art cooling systems to maintain optimal performance in extreme temperatures.
• Harmonic filtering and reactive power compensation to ensure smooth integration into the existing AC grid.

The project enables real-time power flow adjustments, reducing transmission losses and stabilizing the grid in both provinces.
Design & Technical Services

1. Power System Optimization & Electrical Engineering

Our team provided comprehensive electrical design services, including:
• Load flow analysis and fault current studies to ensure grid reliability.
• Electromagnetic compatibility (EMC) solutions to prevent interference with communication and control systems.
• High-voltage insulation coordination to withstand extreme weather conditions.

2. Smart Monitoring & Control Systems

The project integrates advanced digital monitoring and control technologies, including:
• Real-time fault detection for rapid maintenance response.
• Remote SCADA (Supervisory Control and Data Acquisition) systems for centralized monitoring.
• Automated relay protection systems to enhance grid stability and prevent overload.

3. Environmental & Sustainability Measures

As part of our commitment to sustainability, several eco-friendly measures were implemented:
• Low-impact routing to avoid environmentally sensitive areas.
• Reforestation and land restoration programs in affected regions.
• Bird protection devices on towers to minimize wildlife disruption.
After-Sales Service & Maintenance

We provide comprehensive maintenance and after-sales support to ensure the long-term performance of this UHVDC system.

1. Scheduled Maintenance & Inspection

Regular system-wide inspections include:
• Converter station equipment diagnostics (thyristor valves, transformers, and filters).
• Tower structural integrity assessments to prevent corrosion or mechanical failure.
• Conductor and insulator cleaning programs to maintain efficiency.

2. Emergency Response & Fault Repair

A dedicated 24/7 emergency response team is available to address unexpected issues, including:
• Power flow disruptions or voltage fluctuations.
• Structural repairs due to extreme weather or seismic events.
• Rapid replacement of damaged components to minimize downtime.

3. System Upgrades & Future Expansion

Our team offers continuous system improvement solutions, such as:
• Upgrading conductors for increased power capacity.
• Enhancing converter station technology with next-generation semiconductor devices.
• Implementing AI-driven predictive maintenance for improved efficiency.

4. Training & Technical Support

We provide:
• On-site and remote training for power system operators.
• Technical workshops on UHVDC system management.
• 24/7 expert support for troubleshooting and performance optimization.

The Ningxia-Hunan ±800kV UHVDC Transmission Line Project is a game-changing initiative that strengthens China’s national power grid, supports renewable energy integration, and enhances long-distance power transmission efficiency. With cutting-edge engineering solutions, smart monitoring systems, and comprehensive after-sales services, this project ensures a stable, efficient, and sustainable energy supply for decades to come.

For inquiries regarding our UHVDC transmission solutions, engineering design services, or maintenance plans, please contact us today!