Measurement and analysis of switching transients in 500 kV substations

In high voltage substations, secondary equipment placed in the switchyard and inside the control house can be highly sensitive to transient electromagnetic disturbances due to switching operations. In order to evaluate transient electromagnetic environments (EME) and provide guidance for better immunity design of secondary equipment, it is necessary to measure and analyze these transient electromagnetic disturbances. While three new 500 kV substations were powered on, many transient electromagnetic disturbances were measured and recorded. Based on the FFT, an analysis program was developed and used to analyze characteristics of the disturbances. The results are summarized. Comparisons with IEC61000-4 series standards are made and recommendations are given.