TWELVE-PULSE AUTOTRANSFORMER RECTIFIER UNITS Russian patent published in 2017 - IPC G01R31/40 

FIELD: electricity.

SUBSTANCE: invention relates to the twelve-pulse autotransformer rectifier units (ATRU) and, more specifically although not exclusively, to the methods and instruments for the monitoring the concrete states while supplying three-phase power and/or the concrete states of the units' work. The method and instrument for the monitoring the phase retardation in the three-phase twelve-pulse autotransformer rectifier units (ATRU), which receives three-phase input signal when using and provides the direct current nominal output signal, on which the common-mode voltage is superimposed. At least one of the frequency and excursion of the mentioned common-mode voltage is under control in order to determine whether there is phase retardation in the input signal or not. The frequency and/or excursion of the common-mode voltage may also be controlled in order to determine whether there is drop in input voltage or not.

EFFECT: increase in speed of the noted supply voltage anomaly recognition with no need for the direct connection to the three-phase power supply.

12 cl, 3 dwg