America Type Substation

The core electrical structure of the American variant features an integrated “transformer body + high-voltage switchgear + low-voltage distribution” design within a single enclosure. The high-voltage switchgear and transformer are housed in a sealed oil tank, eliminating the need for separate high-voltage switchgear cabinets, resulting in a compact and space-efficient configuration.

High-voltage side protection employs a “load switch + fuse” combination: the load switch handles normal energization/de-energization operations and isolation grounding, while the fuse ensures rapid short-circuit interruption. This coordinated system ensures operational reliability while providing effective protection for transformers and distribution systems, making it ideal for outdoor unattended scenarios.

The key difference lies in adapting system impedance requirements for different voltage levels: 10kV distribution systems may adopt short-circuit impedances of 4% or 4.5%, while 35kV systems can use 6% or 8%. Higher voltage levels require greater short-circuit impedances to limit short-circuit current amplitude. Selection criteria must consider two critical parameters: first, the three-phase short-circuit current value of the distribution system to ensure impedances keep currents within equipment tolerance limits; second, the system’s power supply distance – longer transmission distances necessitate higher impedances to minimize voltage drop and maintain stable power delivery.

Prioritizes oil-immersed fully sealed insulation design tailored for harsh outdoor environments. The sealed structure effectively prevents moisture, dust, and contaminants from intrusion, while the insulating oil delivers dual functions of insulation and heat dissipation without requiring periodic maintenance and offering excellent leak-proof performance. Power frequency withstand voltage standards: 10kV high-voltage side ≥42kV/1min, 35kV high-voltage side ≥95kV/1min, and low-voltage side uniformly ≥2kV/1min. Through optimized insulating oil selection, fully sealed encapsulation technology, and stringent partial discharge control, the system ensures long-term outdoor insulation reliability, making it suitable for high-humidity and dust-prone environments.

The selection of connection group types hinges on matching load types with power distribution system requirements. The Y,yn0 connection group features neutral line extraction and low zero-sequence impedance, making it suitable for three-phase four-wire distribution systems. It is ideal for lighting and civilian load applications in residential communities and commercial buildings, effectively balancing three-phase unbalanced loads. The D,yn11 connection group demonstrates superior interference resistance and enhanced overload/circuit-breaker capacity, catering to industrial heavy-load and inductive load scenarios in factories and industrial parks. This configuration minimizes voltage fluctuations’ impact on equipment performance.

Loss control strictly complies with GB/T 17467 standards: no-load losses range from 0.24kW to 4.0kW, while load losses vary between 1.25kW and 25.0kW, with higher capacity resulting in greater losses. No-load losses represent inherent energy consumption during transformer operation under empty conditions, whereas load losses fluctuate with operational loads. Both parameters directly impact operational efficiency—low-loss design significantly reduces energy waste, lowers long-term energy consumption costs, decreases equipment temperature rise, and extends transformer lifespan, making it particularly suitable for outdoor continuous operation scenarios.

Operational mechanism selection aligns with voltage levels and operational requirements: The 10kV Meibian substation adopts spring energy storage mechanisms featuring simple structure and reliable operation, compatible with manual/semi-automatic operations; the 35kV Meibian substation offers spring or electric mechanisms tailored for high-capacity and long-distance remote control applications.

Technical specifications: Mechanical durability must exceed 10,000 cycles to ensure fault-free operation during prolonged frequent use. Operational mechanisms must match the cabinet’s protection rating (IP33 or higher), incorporate misoperation prevention features to avoid accidental closing/opening, and guarantee outdoor operational safety.