The photovoltaic box-type inverter-transformer unit is a device that combines high-voltage switchgear, oil-immersed or dry-type transformers, inverters, monitoring and control systems, UPS backup power, control transformers, measurement and protection components, and indicating instruments within a high-protection-level enclosure. It converts DC power generated by photovoltaic systems into AC power for transmission to the grid. It features high efficiency, convenience, reliability, and intelligent management. It is suitable for photovoltaic power generation, energy storage, and similar applications. Commonly used transformer capacities for 35kV and below include 2000kVA, 2500kVA, 3125kVA, 4000kVA, and 5000kVA.