The characteristics of the marine environment such as salt spray, humidity, vibration, and limited space require earthing/grounding transformers to meet special design requirements: ① Insulation protection: Use salt spray and mold resistant insulation materials (such as salt spray resistant cast resin), and coat the winding surface with anti-corrosion coating; ② Structural design: Adopt a compact modular structure to adapt to the narrow space of ships/platforms; dry-type (oil-free) is preferred to avoid oil leakage polluting the marine environment; ③ Vibration resistance: Enhance the winding fixing and core clamping structure to meet the mechanical requirements of ship sway and vibration (vibration grade ≥ IEC 60076-5 Class 3); ④ Voltage and frequency: Need to adapt to ship-specific voltage (such as 6.6kV) and frequency (such as 60Hz), and the auxiliary winding needs to meet the power demand of the ship's power station (such as 440V/220V); ⑤ Cooling method: Adopt natural air cooling (KNAN) to avoid fan failure affecting operation and adapt to the closed cabin environment.

Six core parameters must be checked one by one during replacement to avoid compatibility issues: ① System line voltage: Must be consistent with the original (for example, 110kV grade must be replaced for the original 110kV); ② Zero-sequence impedance: The deviation from the original value must be ≤ ±10% to ensure that the protection setting value does not need to be adjusted; ③ Short-time capacity and fault withstand time: Must not be lower than the original grade (for example, the original 30 seconds/5MVA, the new product must meet or be better than this index); ④ Winding structure: Must be consistent with the original type (for example, the original zigzag type cannot be replaced with the wye-delta type) to avoid changes in grounding performance; ⑤ Insulation and cooling method: Must adapt to the original installation scenario (for example, the original outdoor oil-immersed type cannot be replaced with the indoor dry-type); ⑥ Auxiliary winding specifications (if any): The voltage level and capacity must match the original (for example, the original 400V/200kVA, the new product must be consistent) to ensure the normal power supply of the auxiliary load of the substation.