DEVICE AND METHOD FOR PROTECTING FULL WAVE POLYPHASE OR MONOPHASE RECTIFIERS IN CASE OF NON-FUNCTIONING OF SEMICONDUCTOR DEVICES INCLUDED THEREIN

摘要

The invention relates to a device and a method for protecting full-wave polyphase and monophase rectifiers in case of non-functioning of semiconductor devices included therein, such as diodes, thyristors, transistors, etc and also in case of occurrence of an overload. According to the invention, the device is designed to protect a three-phase rectifier in case of non-functioning of semiconductor elements (ES1...ES6) included therein, said device comprising two current transducers (TC1 and TC2) for measuring the current in two phases, an adder-inverter (barred sigma 1) for the recovery of the current on the third phase, three precision rectifiers (RP1, RP2, RP3) for the rectification of the signal obtained at the output of the current transducers (TC1, TC2) and of the first adder-inverter (barred sigma 2) for the addition of rectified signals furnished by the precision rectifiers (RP1, RP2, RP3) and a decision block (BD) for processing the signal obtained at the output of the second adder-inverter (barred sigma 2). According to the invention, the method consists in tracking the value of the current through load, verifying the lack of pulses by comparing the maximal value of the current with the average value, knowing that, when pulses are absent, the difference between the Imax value and the Imed value of the current rises and in the numbering of the pulses with in a time interval, respectively.