Fast transient radiated and conducted electromagnetic interference measurement within power system substations

Radiated and conducted interference is a major concern in modern power systems as increasingly, control is being performed by highly susceptible electronic circuitry. It is therefore necessary to characterise this interference in order to guard against it. There are a number of methods of achieving this, and this paper looks at the method which has been developed and used by the University of Strathclyde in conjunction with work sponsored by Scottish Power plc and The National Grid Company plc. The measurement system consists of two parts, a radiated interference system and a conducted interference system. These two parts can be used independently or can be linked by a common trigger system to allow both sets of measurements to be referenced to a specific point in time. A number of sensors and probes are used to enable coincidental measurements at various points over a large range of frequencies, field levels, voltages and currents