An Improved Technique for Calibrating and Testing Power System Generator Automatic Synchronizing and Speed Hatching Relays

The design of a unique special purpose instrument for calibrating and testing power system automatic synchronizing and speed matchiing relays is described. The unit is constructed using inexpensive integrated circuit components and provides a direct digital readout of slip frequency from 0.05 Hz to 0.50 Hlz resolution and advance angle from 0 to 99.9 degrees with 0.1 degree resolution. This device eliminates the need for expensive test equipment previously required, expedites the test procedure and solves the problem of referencing against a variable bus frequency source.