A new method of transient overvoltage monitoring for substation

The electromagnetic voltage transformer or capacitive divider is usually used to monitor overvoltage in power system. The transient response of electromagnetic voltage transformer is slow, so they can´t reflect transient overvoltage accurately. Optical voltage sensor is a new type of voltage measuring appliance, which measures voltage by crystal electro-optic effect, and transmit data through optical fiber. The authors bring forward a new method of transient overvoltage monitoring for substations. The paper stated that the working principle and characteristics of optical voltage sensor, data acquisition module, data processing and analyzing procedure, as well the method of overvoltage type judging. It is helpful to provide theoretical evidence for predicting apparatus insulation failure probability, the limit of life span, and improving insulation co-ordination.