Electronic parallel coupling of AC networks - prevents damage due to coupling lines of differing frequency or phase

摘要

The electronic unit provides as the parallel coupling of AC networks or the connection into a network of a generator. The unit determines the difference in frequency or phase angle allowable between the systems to be coupled and has an auxiliary unit regulating the permited differences. The design is intended to prevent damage due to coupling into the networks lines carrying unacceptable frequency or angle excursions. The auxiliary circuit has a series of resistors connected by a switching system to a voltage source, the resistors forming with a common series resistance a potentiometer. The take-off point feeds a monitoring arrangement also being fed by a voltage proportional to the frequency or angle difference between the networks.