Ultra-High Voltage (UHV) transmission projects are essential infrastructure for optimising energy resource allocation, facilitating the large-scale integration of clean energy, and developing China’s new power system. As China continues to expand its UHV power grid, project construction is growing in scale, while technical complexity and management requirements are also increasing. Improving construction quality and efficiency through standardised management, refined project control, and digital technologies has therefore become a key priority in promoting the high-quality development of UHV projects.

1. Strengthening Standardisation to Establish a Solid Foundation for UHV Project Quality

UHV projects are characterised by long construction periods, demanding technical requirements, a wide range of specialised disciplines, and complex construction environments. These characteristics place high demands on engineering design, equipment manufacturing, construction and installation, as well as operational management. Establishing unified technical standards and management systems is essential to ensuring project quality and improving construction efficiency.

In UHV project development, standardised management covers multiple stages, including project planning, engineering design, equipment procurement, construction and installation, acceptance, and commissioning. By improving standardised management procedures, regulating project documentation, and unifying technical requirements and operational processes, potential inconsistencies between different project stages can be reduced, thereby improving the standardisation and consistency of project delivery.

For UHV DC transmission projects, engineering measures must also be tailored to the geographical, climatic, and environmental conditions of different regions. For example, when carrying out construction in deserts, Gobi regions, and high-altitude areas, particular attention must be paid to ground settlement, sand erosion, and the impact of harsh environmental conditions on equipment and transmission lines. Targeted design and construction measures can help improve project adaptability and ensure long-term operational reliability.

2. Enhancing Refined Management to Strengthen Full-Lifecycle Project Control

UHV project construction involves numerous critical pieces of equipment, complex construction procedures, and coordination among multiple stakeholders. This places systematic demands on safety, quality, and cost management. Moving from traditional experience-based management towards comprehensive, refined project management is an important guarantee of high-quality construction.

In terms of safety management, greater emphasis should be placed on identifying risks and investigating potential hazards at construction sites. Technologies such as drone inspections and intelligent monitoring can be used to improve the timeliness and accuracy of on-site management.

In terms of quality management, a comprehensive quality control mechanism should cover equipment manufacturing, incoming inspections, construction and installation, and final project acceptance. Third-party testing, equipment quality traceability, and supervision of critical construction procedures help ensure that materials, equipment, and construction work comply with relevant technical standards. Meanwhile, the adoption of intelligent construction equipment can improve the standardisation and precision of installation operations.

In terms of cost management, cost control should be integrated throughout the entire project lifecycle, covering feasibility studies, engineering design, tendering and procurement, construction, and final settlement. Full-process budget management and dynamic cost analysis can improve resource allocation efficiency and help achieve a balance between construction quality, project schedules, and investment returns.

3. Advancing Digitalisation and Intelligent Construction to Upgrade UHV Project Management

As digital technologies become increasingly integrated with power infrastructure development, digitalisation and intelligent technologies are emerging as important directions for the future of UHV project construction.

By establishing digital project management platforms and integrating information on project schedules, construction quality, safety management, equipment status, and cost control, project stakeholders can achieve comprehensive data collection, dynamic monitoring, and coordinated management throughout the construction process. The application of technologies such as digital modelling, intelligent construction equipment, drone inspections, and AI-powered analysis can also improve on-site management efficiency, accelerating the transition from traditional project management towards digital and intelligent construction models.

At the same time, advances in prefabricated construction, digital design, and intelligent construction technologies are helping optimise construction organisation, reduce on-site operations, and improve the standardisation of project delivery. Promoting independent innovation in key technologies and equipment, while increasing the localisation of core equipment and supporting systems, will also provide strong support for the continued development of China’s UHV projects. 

Refined inspection through human-machine collaboration at a substation. 

Source: State Grid Corporation of China.

4. Strengthening the Coordination of Key Equipment to Ensure the Safe and Stable Operation of UHV Grids

The high-quality development of UHV projects depends not only on advanced transmission technologies and comprehensive project management systems but also on the coordinated integration of various critical power equipment. In addition to key equipment such as transformers, converter valves, and switchgear, reactors are also important components of power systems, playing a significant role in grid regulation and operational stability.

Depending on system configurations and operational requirements, reactors can perform functions such as limiting short-circuit currents, regulating reactive power, and mitigating harmonics. Among them, dry-type air-core reactors feature an iron-core-free structure and use air as their primary insulating medium. They offer advantages including the absence of magnetic core saturation, good linear operating characteristics, and no requirement for oil insulation. Depending on the applicable voltage level and system configuration, they can be used in applications such as current limitation, shunt reactive power compensation, and harmonic filtering, providing important technical support for power system operation.

As UHV networks continue to expand and large-scale renewable energy sources, including wind and solar power, are increasingly integrated into the grid, power system operating conditions and power flow patterns are becoming more complex. This creates higher demands on grid regulation capabilities, equipment adaptability, and operational reliability. Supporting equipment such as reactors can contribute to electrical parameter regulation and operational control in accordance with system requirements, providing important equipment support for the development of safe, stable, and efficient power grids.

Therefore, UHV project development must focus not only on technological innovation in major infrastructure, such as transmission lines and converter stations, but also on the design compatibility, manufacturing quality, and operational performance of supporting equipment such as reactors. Strict quality control is required at every stage, from technical design and material selection to manufacturing, factory testing, and on-site installation, ensuring that equipment is fully compatible with grid systems and the overall operational requirements of each project.

5. Promoting the Development of China’s New Power System Through High-Quality Engineering

Looking ahead, as China continues to adjust its energy mix and expand its installed renewable energy capacity, UHV networks will play an increasingly important role in cross-regional energy resource allocation, clean energy integration, and the development of a unified national electricity market.

During the 15th Five-Year Plan period (2026–2030), UHV project development is expected to advance further towards larger-scale, standardised, digitalised, and intelligent construction. Through continuous improvements to engineering standards, stronger full-lifecycle management capabilities, innovation in key technologies, and better coordination among power equipment systems, China’s UHV transmission projects are expected to achieve higher construction quality and operational efficiency, providing solid support for the development of the new power system.

As a power equipment supplier, DKNC will continue to monitor developments in UHV technology and China’s new power system. With a focus on grid safety and stability as well as renewable energy integration, DKNC will follow technological developments and emerging applications for power equipment, including dry-type air-core reactors. The company will continue to enhance its product adaptability and supporting service capabilities, contributing to power infrastructure development and the green and low-carbon energy transition.

Reference: State Grid Corporation of China