Prefabricated substations integrate high voltage control, protection, and transformation, and are widely used in the power grid. High voltage load switches and high voltage fuses are placed inside oil immersed transformers in substations, with two structural forms: shared oil tanks and split oil tanks. The oil tank is a fully sealed structure, equipped with components such as an oil temperature gauge, oil level indicator, pressure gauge, pressure gauge, oil pressure valve, and drain valve to monitor the operation of the transformer.