Optimal Application of Prefabricated Substations in Industrial Projects
Time：2025-09-23 Auther：ZTelec-www.ztelectransformer.com
Prefabricated substations integrate high-voltage switches, transformers, low-voltage switches, energy meters, and reactive power compensation equipment in compact boxes connected through specific wiring schemes. They are primarily used in three-phase AC systems with rated voltages of 10/0.4 kV, handling line control and power distribution. Optimal application requires careful design tailored to the project’s specific requirements.
Core Advantages of Prefabricated Substations
1. High Stability and Reliability
Fully insulated design with no exposed live parts eliminates electric shock risks. Oil-free operation reduces fire hazards. The enclosure uses aluminum-zinc-coated steel with fireproof thermal insulation materials and includes air conditioning and dehumidification devices. It can operate stably in environments from -40℃ to +40℃, suitable for harsh industrial climates.
2. Flexible Combination and Rapid Deployment
Compact design allows a single box to form a standalone system. Configurations include:
Full-box structure: Integrates 35kV and 10kV equipment within the box. Ideal for space-constrained industrial projects like factories and data centers.
Hybrid structure: 35kV equipment outdoors, 10kV and control inside the box. Suitable for upgrading rural grids or retrofitting old substations, reducing investment costs by 40%-50%.
Modular expansion: Box-type transformer units can be added in phases to meet construction needs without high upfront investment.
3. Intelligent Operation, Maintenance, and Cost Optimization
Equipped with microcomputer-based automation systems, prefabricated substations implement “four remote” functions (telemetry, telesignaling, remote control, and remote adjustment). Features include remote monitoring, fault warning, automatic temperature and humidity control. Intelligent systems in large industrial sites, such as steel mills or chemical parks, enable real-time monitoring, proactive fault detection, and reduced unplanned downtime. Prefabrication shortens on-site installation to 5-8 days, improving efficiency by over 90% and reducing labor and time costs.
Typical Industrial Applications and Optimal Configurations
Scenario 1: Main Step-Down Substation
Draws 10kV or 20kV from the grid, steps down to 400V, and distributes power to workshops or power centers.
High-voltage side: Dual-circuit incoming lines with a ring main unit (RMU), ensuring backup and interlocking for uninterrupted supply.
Transformer: SCB series epoxy resin cast dry-type transformer, flame-retardant, explosion-proof, low-noise, with strong overload capacity. Typical capacities: 800kVA to 2500kVA, with optional backup transformers.
Low-voltage side: Fixed or drawer-type switchgear (MNS, GCS series), intelligent circuit breakers, overcurrent, and grounding protection. Reserve generator interface for automatic transfer switches (ATS).
Intelligent system: Integrated monitoring for temperature, humidity, over-temperature protection, access control alarms, and remote management for unmanned operation.
Scenario 2: Large Factory Workshop Distribution
Prefabricated substation at the load center reduces low-voltage line losses and voltage drop.
High-voltage side: Single-circuit radial supply with load switch + fuse combination.
Transformer: Dry-type transformer, 400kVA to 1000kVA.
Low-voltage side: Multiple outgoing circuits based on equipment distribution; motor protection breakers for heavy motor loads.
Special considerations: Enhance sealing and heat dissipation with forced ventilation for harsh environments.
Scenario 3: Dedicated Substation for Specific Equipment
For central air conditioning, water pumping stations, sewage plants, or R&D centers.
High-voltage side: Simple load switch-fuse system.
Transformer: Capacity matches equipment load; adjust for starting currents if necessary.
Low-voltage side: Connect directly to equipment control cabinets for fewer circuits but higher current loads.
Optimal application of prefabricated substations in industrial projects requires a customized, systematic approach. By analyzing project-specific needs, selecting appropriate structures, reliable electrical configurations, protection measures, and intelligent designs, prefabricated substations provide safe, reliable, economical, efficient, and intelligent power supply solutions for industrial environments.
