Comprehensive Analysis of Transmission and Substation Engineering Construction

Comprehensive Analysis of Transmission and Substation Engineering Construction

I. Basic Concepts

The construction of transmission and transformation projects is a core component of power engineering. It refers to the process of transmitting high-voltage electricity generated by power plants through transmission lines to substations, where transformers step down the voltage to low-voltage electricity before it is finally distributed to end-users. This process encompasses both transmission-line engineering—such as overhead lines and cable lines—and substation engineering, which includes civil construction and installation of electrical equipment. It serves as the critical link connecting power generation with electricity consumption.

II. Construction Process

1. Project Initiation and Planning
   • Project Approval Clearly define the construction objectives, scale, voltage level, and investment budget.
   • Feasibility Study Assess technical, economic, and environmental feasibility, and develop a preliminary design plan.
   • Design refinement Complete the electrical design (circuit routing, tower and pole selection), civil engineering design (substation layout), and environmental design (ecological impact assessment).
2. Construction Preparation
   • Tendering and Procurement Select the construction contractor and procure materials and equipment that meet the standards.
   • On-site inspection Review geological conditions and develop a construction plan (customized design required for special terrains).
3. Construction phase
   • Foundation construction Select the pile foundation type based on geological conditions (e.g., use anchor piles for rocky foundations and cast-in-place piles for soft soils), and control the depth error of the pile foundation to within ±50 mm.
   • Pole and Tower Erection Use segmented lifting (for steel towers) or overall erection (for concrete poles); the verticality deviation shall be ≤ 0.3% of the tower height.
   • Wire laying During tension stringing, the conductor shall be kept at least 3 meters above the ground, and the sag error shall be within ±2.5%. For critical crossing points (such as railways), double safety measures shall be implemented.
   • Equipment installation After installation, the transformer shall be left undisturbed for 72 hours before testing. The error in the circuit breaker’s closing and opening times shall be no more than 0.02 seconds. GIS equipment shall be filled with SF6 gas for protection.
4. Debugging and Acceptance
   • System debugging Test voltage stability and current load capacity.
   • Acceptance Review Organize expert acceptance and put it into operation only after confirming that it meets design and safety standards.
5. Post-operation and maintenance
   • Equipment maintenance Regular maintenance, fault troubleshooting, and data analysis to extend equipment lifespan.
   • Smart Monitoring Utilize digital twin technology to build a 3D operations and maintenance model, integrating data across the entire lifecycle.

III. Key Technologies

1. Foundation construction
   • Rock foundation: anchor rod foundation + high-pressure grouting reinforcement.
   • Soft Soil Foundation: Bored Piles + Topsoil Removal and Replenishment Technology.
2. Pole and Tower Erection
   • Special terrain: In river-crossing areas, the suspended pole-lifting method is employed; in mountainous regions, the internal suspension with external guy lines approach is used.
   • Bolt tightening: Use the diagonal tightening method, applying force in three stages, with a final tightening torque error of ≤ ±5%.
3. Wire laying
   • Tension stringing: The traction machine and the tensioner work in coordinated control to manage the sag.
   • Drone Inspection: Equip with an infrared thermal imager to detect overheating points on equipment.
4. Equipment installation
   • Transformer: Verification of impulse recorder data and partial discharge testing after installation.
   • Secondary wiring: Dedicated wire-stripping tool, wire number labels printed on both sides, with zero tolerance for error rates.

IV. Safety Management

1. Responsibility System Clearly define the safety responsibilities of the project department, the supervisor, and the contractor, and establish a “Site Safety Committee.”
2. Risk management High-risk operations (such as work at heights or in deep pits) shall be conducted under a dual-supervisor system, and construction machinery shall be equipped with collision-avoidance systems.
3. Emergency Management Develop emergency response plans and conduct regular drills for scenarios such as electric shock and falls from heights.
4. Safety Training All personnel must be certified before taking up their posts, and workers performing high-altitude operations undergo daily blood pressure monitoring.

V. Quality Control

1. Material inspection Three sets of specimens shall be randomly selected from each batch of steel strands for testing, and the samples will be submitted in a blinded manner.
2. Construction technology ：
   • Reinforcement work: Before tying, verify the drawings and use No. 20 iron wire to tie reinforcing bars with diameters greater than 12 mm.
   • Concrete placement: The curing period shall be ≥7 days, and backfilling shall be carried out after acceptance of concealed works.
3. Digital Management BIM technology simulates concurrent operations, and electronic fencing provides early warnings for critical nodes.

VI. Environmental Protection

1. Air Pollution Prevention Dust suppression using mist cannons; exposed ground surfaces covered with close-mesh netting.
2. Water Environmental Protection Wastewater from sedimentation ponds is treated to handle construction wastewater, while domestic sewage is discharged into the municipal sewer network.
3. Ecological conservation Topsoil removal and restoration, vegetation recovery (broadcasting grass seeds, tree planting).
4. Noise Control Soundproof barriers are installed, and equipment layout is optimized to keep it away from sensitive areas.

VII. Development Trends

1. Mechanization and Intelligentization ：
   • Develop all-terrain adaptive equipment (such as miniature foundation construction machinery for mountainous areas).
   • Promote drone inspections and 5G remote monitoring to reduce human intervention.
2. Green construction ：
   • Adopting modular substation technology shortens the construction period by 60%.
   • Carbon fiber conductors enhance current-carrying capacity by 40%.
3. Technological innovation ：
   • Develop intelligent tensioning equipment to achieve automatic adjustment of conductor tension.
   • Explore Beidou positioning technology to adjust sag in real time.

The construction of transmission and transformation projects is evolving toward safety, environmental protection, and intelligence. Technological innovation and full-lifecycle management have become the core drivers for upgrading the industry.