The S18/20/22 series Renewable energy (wind/photovoltaic) china style transformer is a three-phase double winding oil immersed, self cooled, non excited voltage regulating, fully sealed structure. Composed of transformer body, oil tank, radiator, high and low voltage side insulation sleeves, oil level gauge, pressure relief valve, temperature control gauge, oil storage tank (generally equipped with capacity ≥ 630kVA), gas relay, moisture absorber, etc., it is an important core component of the Hua style box transformer. The Hua style box transformer is composed of high-voltage electrical components (high-voltage isolating switches, high-voltage fuses, etc.), low-voltage electrical components (low-voltage isolating switches, low-voltage current transformers, fuses, etc.), and the box body. Wide capacity range, with voltage levels of 40.5kV and below. Meets the latest national energy efficiency standards, has strong overload capacity, is energy-saving and environmentally friendly, and is used in urban and rural buildings, residential areas, high-tech development zones, small and medium-sized factories, mines, wind power projects, and single box mounted wind and photovoltaic projects with large capacity.