During the operation of the shunt capacitor bank in a substation

various faults may occur inside the capacitor due to the influence of such factors as dielectric insulation aging

the overvoltage with large amplitude may generate and threaten insulation of the shunt capacitor bank. ATP-EMTP is used to simulate the voltage and current variation characteristics of the shunt capacitor bank in the 66 kV substation at such four fault conditions as capacitor component breakdown and arcing

reliable fusing of faulty components

capacitor multi-explosion

capacitor multi-explosion and reignition. It is shown by the study result in case of the first two faults

the node voltage of the shunt capacitor bank is basically unchanged and the current flowing on the healthy capacitor element has a slight increase. While

in case of the latter two faults

the remarkable over voltage and over current will occur on the node of capacitor bank

which threatens the insulation of capacitor bank and shall be protected.