Development and application of a power-system digital transient recorder

This paper describes the features, hardware and software functions of a digital data-acquisition unit designed for monitoring and recording power-system transients. It has been configured for connection, via appropriate isolation units, to system voltage and current transformers. The raw digitised voltage and current quantities can either be stored directly onto magnetic data cartridges or be processed on-line to produce cycle-average voltage, power and frequency quantities before being stored onto the cartridges. These data, arranged in computer-compatible format, can then be readily accessed for off-line analysis work. Two application examples of this recorder, taken from recent field tests performed on a static-reactive-power compensated radial network, are included. The results are discussed and compared with those obtained from simulation studies.