METHOD AND APPARATUS FOR SUB-HARMONIC PROTECTION

摘要

A method and device for detecting damaging sub-harmonic frequencies in a power system, and recording data or initiating protective action. A microprocessor based sub-harmonic protection relay (S-PRO) monitors system voltages and currents from voltage and current transformers on the power system that may be present in the 5 Hz to 25 Hz frequency window. The user of S-PRO has full programming control to select bandwidths of frequencies or specific frequency components of the collected system voltages and currents. S-PRO can be user programmed to either detect the sub-harmonic power quantities and record them for future use in simulations or to initiate protective action. Protective action may include initiating output contact closure on the device to shut down equipment or to initiate corrective actions to prevent damage.