Arrangement for regulation of current flow for parallel connected semi-conductor rectifiers

Claim 1

IN A SUPERVISED RECTIFIER SYSTEM FOR RECTIFYING A POLYPHASE ALTERNATING CURRENT THE COMBINATION COMPRISING A PLURALITY OF BRANCH RECTIFIER CIRCUITS FOR EACH PHASE TO BE RECTIFIED CONNECTED IN PARALLEL, A SEMICONDUCTOR RECTIFIER VALVE CONNECTED IN EACH SUCH BRANCH CIRCUIT, A CURRENT TRANSFORMER IN EACH SUCH BRANCH CIRCUIT AND HAVING THE PRIMARY THEREOF IN SERIES WITH ITS CORRESPONDING SEMICONDUCTOR RECTIFIER VALVE FOR MONITORING CURRENT FLOW THERETHROUGH IN THE FORWARD DIRECTION, A SUM CURRENT TRANSFORMER HAVING ITS PRIMARY IN SERIES WITH A PART OF SAID RECTIFIER SYSTEM CARRYING THE SUM OF ALL THE FORWARDLY FLOWING CURRENTS IN SAID BRANCH CIRCUITS, A FIRST CURRENT-COMPRISING DEVICE, CIRCUIT MEANS CONNECTING THE VOLTAGE IMPULSES OBTAINED FROM THE SECONDARIES OF SAID BRANCH CURRENT TRANSFORMERS RESPECTIVELY AS INPUT SIGNAL IMPULSES TO SAID FIRST CURRENT-COMPARING DEVICE, THE CHARACTER OF THE OUTPUT SIGNAL FROM SAID FIRST CURRENT-COMPARING DEVICE BEING DEPENDENT UPON WHETHER OR NOT ALL OF SAID INPUT SIGNAL IMPULSES ARE COINCIDENT, A SECOND CURRENT-COMPARING DEVICE, AND CIRCUIT MEANS CONNECTING THE VOLTAGE IMPULSES OBTAINED FROM THE SECONDRY OF SAID SUM CURRENT TRANSFORMER AND THE OUTPUT FROM SAID FIRST CURRENT-COMPARING DEVICE RESPECTIVELY AS INPUTS TO SAID SECOND CURRENT-COMPARING DEVICE, THE CHARACTER OF THE OUTPUT SIGNAL FROM SAID SECOND CURRENT-COMPARING DEVICE BEING DEPENDENT UPON WHETHER OR NOT ALL THE CURRENT FLOWS IN SAID BRANCH RECTIFIER CIRCUITS ARE COINCIDENT.