Applications of new technology in power substations
The authors describe the applications of some of the more modern technologies to instrument designed specifically to operate in utility substation environments. Particular emphasis is placed on the use of CMOS logic, processor, and memory circuits, high-density flexible magnetic disk media, and high-capacity Winchester technology storage devices. The operating history of a number of units over a five-year period is reported, as well as the steps taken to protect these devices in a hostile environment. In addition, areas requiring specific improvement and adaptation are noted.<<ETX>>
Field Experience of Digital Fault Recorders and Distance Relay in EHV Substations
Five samples of a digital fault recorder have been in use since 1981 in the EDF's 400 kV substations. After a description of their design and performances (5 kHz sampling frequency on each of the 8 analog and 16 logical inputs), this paper gives some examples of the data they have collected. Particularly, one recorder has monitored a digital distance relay, and allowed a precise analysis of its behaviour. An evaluation of operational and reliability results is given.
Substation Electromagnetic Interference, Part I: Characterization and Description of the Transient EMI Problem
The problem of electromagnetic interference with automation and control equipiment in power substations is defined in detail. Instrumentation techniques for measuring electric and Tmagnetic fields are reviewed and actual field data is presented. Several approaches to equipment protection and susceptibility testing are presented from the utility perspective. Examples of transient EHI and conducted interference are included and recommendations are miade as to equipment hardening and design techniques.