With the development of new energy and flexible power transmission technology

the demand of power system to the self-healing capacitor is more.Theoretically

the self-healing capacitor cannot avoid completely occurrence of the self-healing failure

which will develop gradually into such serious accidents as fire and explosion etc.Therefore

the self-healing failure must be removed from the power supply as soon as possible.The reason that the HV self-healing capacitor is not widely promoted and used in the power system is due to no protection measures for the self-healing failure.In this paper

the generated gas mount and the gas contents characteristic of the capacitor in case of self-healing failure is obtained by the selfhealing failure simulation

a kind of the self-healing failure protection is proposed on the basis of hydrogen contents variation

the corresponding monitoring circuit is developed and installed inside the capacitor unit for simulation test.It is shown by the test result that after self-healing failure

the hydrogen contents monitoring circuit can output signal around 15 mV

which can be used to trip the protection device and its sensitivity is higher than that of pressure protection device.