Monitoring circuitry checking performance of pulsed power rectifier - gives comprehensive evaluation of functional faults using comparator with PLL referencing

摘要

A three phase system (UVW) drives a D.C. rectifier unit (1) supplying a load (4). A representative current (I) or voltage (U) signal from the rectifier (1) is subjected to band-pass filter (A) and results in regular rectangular pulses of frequency in times supply frequency under healthy conditions from a comparator (B). A phase locked loop unit (C) contg. phase comparators (DE) filter (F) and independent voltage controlled reference oscillator (G) enables actual rectified output pulses to be compared for shape and number against a stored norm. A logic unit (H) evaluates any divergence from norm. for fault recognition and correction. USE/ADVANTAGE - Is less inexpensive than other systems of its type. Affords comprehensive check of semiconductor firing sequence, phase disconnection, phase angle drift or incipient failure of components.