Harmonic resonance control and protection system for switched power factor control capacitor devices

摘要

A method and system for preventing sustained resonance conditions in a power system involves measuring voltage and current samples on a conductor to which a plurality of controlled capacitors are operatively coupled. The measured voltage and/or current is utilized to identify a resonance condition. The method or system determines whether the resonance condition is due to switching of a controlled capacitor and, if so a corrective switching operation is performed after a first time delay. If the resonance condition is determined not to be due to the switching of a capacitor, then a second switching operation, in which a second controlled capacitor is switched after a second time delay, is performed. The second time delay is preferably greater than the first time delay.