PHASE CONTINUOUS COMPARISON TYPE SYNCHRONIZING SIGNAL DETECTING CIRCUIT OF POWER CONVERTER

摘要

PURPOSE:To prevent the step-out of synchronization due to a decrease in a 3- phase AC voltage and to rapidly detect an AC synchronizing signal by standardizing the synchronizing signal and applying the synchronized signal directly or through a 3-phase/2-phase converter to a phase difference detecting arithmetic circuit. CONSTITUTION:A standardizing circuit 20 is provided between a 3-phase/2-phase converter 10 and a phase difference detecting arithmetic circuit 11. The circuit 20 is composed of an absolute value arithmetic circuit 21 and a divider 22. The circuit 21 inputs the output signal of the converter 10, calculates its absolute value and applies the calculated result to the divider 22. The divider 22 divides the output signal of the converter 20 by the output signal of the circuit 21, and applies the value to the circuit 11.