Since many defects and faults of high voltage shunt capacitor during operation period

and the present maintenance and operation mode in power grid cannot effectively predict the faults in advance

the condition based maintenance is difficult to be implemented

thus causing the fault of single unit of capacitor to develop into complete bank fault and bigger safe operation hidden danger of equipments.According to the smart power grid construction and condition based maintenance requirements of State Grid of China Corp（SGCC）

it is necessary to develop a kind of on-line monitoring system for high voltage shunt capacitor in order to find out abnormalities of equipments and provide the basis for condition-based maintenance of high voltage shunt capacitor.In this paper

the on-line monitoring measurement method of high voltage shunt capacitors which based on the detection of temperature

capacitance and imbalance voltage is raised and its principle and structure are introduced.It is indicated by the actual operation that the on-line monitoring system for high voltage shunt capacitor can monitor the capacitance up to class 0.5

can find abnormalities of the equipment quickly and has important practical significance to reduce the defect and accident rate of high voltage shunt capacitor.