Test results and system performance

SYSTEM DISTURBANCES due to the tests were not serious and caused but little trouble and but few complaints except from consumers at points nearby. Recording voltmeters were installed during the tests at all of the important 132-kv. substations on the system. Typical charts from these recorders are shown in Fig. 4. While inertia and over-travel in a voltmeter of this type are responsible for some of the variations in the charts, nevertheless a clear comparison may be noted between the severity of disturbances caused by high speed and by ordinary circuit breakers. The most striking comparison is revealed by the charts obtained at points close to the Philo plant, such as those taken at Crooksville. Here again the inertia of the moving pen instrument plays a large part in the record obtained, but at the same time a fairly accurate comparison may be drawn. In addition it is felt that a dip, the duration of which is too short for the recording voltmeter pen to follow, may also be too short to cause a synchronous machine to fall out of step.