CVT capacitance on-line monitoring method based on zero sequence voltage monitoring

The invention discloses a CVT capacitance on-line monitoring method based on zero sequence voltage monitoring. The method comprises the steps of: S10, parallelly reading the zero sequence voltage of at least one CVT by a plant station monitoring system, wherein the zero sequence voltage is normal if only deviating from normal values; S20, querying each CVT for detecting whether each zero sequence voltage exceeds a first voltage threshold, and for one CVT, if the zero sequence voltage thereof is larger than or equal to the first voltage threshold, entering a step S30; and S30, counting the abnormity duration time of zero sequence voltage of the CVT, judging whether the zero sequence voltage of the CVT exceeds a second voltage threshold, if the zero sequence voltage is smaller than the second voltage threshold and the duration time is larger than a first set time, then determining that the capacitance of the CVT is broken down. The operation condition of the CVT capacitance is accurately judged by the utilizati