The key to improve the insulation level and accuracy of electronic voltage transformer is to improve the withstand voltage level and voltage division ratio of capacitive divider. Inner string type of metallized film capacitors is adopted

the low electrical field strength design of rated voltage of the film（1/3-1/2） is taken for the operating field strength and the design of 0.003A/m low line current density is used as well as a series of anti-oxidization measures are adopted

which can not only avoid effectively capacitance loss and operation life

but also assure long term operation accuracy of the divider. The inner capacitor units are installed as per the sequence of the magnitude of electrical potential so to assure the complete insulation performance of the capacitive divider.