The core conclusion: Oilimmersed transformers have standardized capacity specifications globally, with common ranges from 10 kVA to 250,000 kVA, aligned with IEC or GB standards for power system matching.

　　Common Capacity Specifications (LowMedium Voltage, ≤35kV)

　　Small capacity: 10 kVA, 20 kVA, 30 kVA, 50 kVA, 80 kVA, 100 kVA.

　　Medium capacity: 125 kVA, 160 kVA, 200 kVA, 250 kVA, 315 kVA, 400 kVA, 500 kVA, 630 kVA, 800 kVA, 1000 kVA.

　　Large capacity: 1250 kVA, 1600 kVA, 2000 kVA, 2500 kVA, 3150 kVA, 4000 kVA, 5000 kVA.

　　LargeCapacity Specifications (High Voltage, ≥110kV)

　　Typical ratings: 6300 kVA, 8000 kVA, 10,000 kVA, 12,500 kVA, 16,000 kVA, 20,000 kVA.

　　Extralarge capacity: 25,000 kVA, 31,500 kVA, 40,000 kVA, 50,000 kVA, up to 250,000 kVA for ultrahigh voltage (UHV) applications.

　　Key Notes on Specifications

　　Capacities follow logarithmic progression (R10 series: 1.25x interval) for optimal power matching and cost control.

　　Standards differ slightly by region: IEC (global) and GB (China) are mostly consistent, while ANSI (US) has partial variations (e.g., 75 kVA, 150 kVA).

　　Custom capacities are available for special scenarios, but standardized models are preferred for supply chain and maintenance efficiency.