本指南介绍了当电压水平高于1 kV时，三相交流电力系统中瞬态过电压的在线监测和记录方法。它适用于变电站、发电站和输电线路中瞬态过电压的定性测量。结果可用于电力系统运行状况分析。本指南不包括GIS隔离开关操作引起的快速瞬态过电压（VFTO）的在线监测和记录。

This guide presents methods for online monitoring and recording of the transient overvoltages in a three-phase AC power system when the voltage level is higher than 1 kV. It applies to the qualitative measurement of transient overvoltages in substations, power stations, and transmission lines. The results are used for power system operating condition analyses. This guide does not include online monitoring and recording of very fast transient overvoltage (VFTO) caused by operation of GIS disconnectors.