(1) the selection and configuration of the voltage transformer shall be subject to the following conditions [6] :6 -- 20kV power distribution device in the house, generally adopts oil-immersed insulation structure, or adopts resin pouring insulation and common voltage transformer.35 -- 110kV power distribution device generally adopts voltage transformer with oil-immersed insulation structure.When the capacity and accuracy level of 220kV and above distribution devices meet the requirements, capacitive voltage transformers are generally used.When it is necessary to check and monitor the single-phase grounding of the primary circuit, three-phase five-column voltage transformers or single-phase voltage transformers with a third winding should be selected.