Rated voltage is an important parameter of capacitor in shunt capacitor installation.Too low rated voltage will increase the fault rate and decrease the operation reliability

while higher rated voltage will cause the low utilization ratio of resource and equipments.In this article

the selection principle of the rated voltage of shunt capacitor in engineering is introduced

and the calculation formula of the rated voltage of shunt capacitor is derived out by using the circuit theory.At the same time

the increasing coefficient of capacitor operation voltage caused by parameter variation of capacitor installation has been derived out and some applied fault criterions have been presented

which offer reference for the design and operating of capacitor installation.