Rotating alternating current generator system

Abstract

Abstract A ROTATING, ALTERNATING CURRENT GENERATOR SYSTEM IS DESCRIBED IN WHICH AN EXCITER DRIVEN WITH THE GENERATOR SHAFT SUPPLIES GENERATOR FILED CURRENT AS WELL AS THE ENTIRE FIELD CURRENT REQUIRED BY THE EXCITER. D-C FIELD CURRENT FOR THE EXCITER IS OBTAINED FROM THE EXCITER OUTPUT, RECTIFIED BY A CONTROLLED RECTIFIER UNIT. REGULATION OF GENERATOR OUTPUT VOLTAGE (OR SOME OTHER VARIABLE MEASURABLE IN THE SYSTEM AS A VOLTAGE OR CURRENT) IS OBTAINED THROUGH CONTROL OF THE FIRING ANGLE OF THE CONTROLLED RECTIFIER UNIT, THERBY VARYING THE LEVEL OF EXCITER FIELD CURRENT TO ADJUST FOR CHANGES IN GENERATOR OUTPUT CONDITIONS. TO OBTAIN REGULATION OVER A WIDE RANGE OF EXCITER OUTPUT VOLTAGES CONTAINING SUBSTANTIALLY DISTORTION, FIRING VOLTAGE FOR FIRING THE CONTROLLED RECTIFIERS IN THE CONTROLLED RECTIFIER UNIT IS OBTAINED BY AMPLITUDE-CLIPPNG THE EXCITER OUTPUT VOLTAGE AT A CONSTANT LEVEL INDEPENDENT OF EXCITER OUTPUT AMPLITUDE. THE FIRING VOLTAGE WAVEFORM GENERATOR CONTAINS A CLIPPING CIRCUIT CAPABLE OF ACHIEVING SUCH CLIPPING TO THE SAME LEVEL FOR ALL RECTIFIERS. THE FIRING VOLTAGE WAVEFORM GENERATOR FIRES THE RECTIFIERS THROUGH MAGNETIC CORE FIRING CIRCUITS. CONTROL OF THE EXCITER FIELD CURRENT, AND THUS OF A PARTICULAR SYSTEM VARIABLE (E.G., GENERATOR OUTPUT VOLTAGE) IS ACHIEVED THROUGH CONTROL OF THE RESET FLUX PRODUCED IN THE MAGNETIC CORES IN THE FIRING CIRCUITS. A MANUAL REGULATOR UNIT IS PROVIDED FOR REGULATING EXCITER FIELD CURRENT TO PROVIDE CONSTANT EXCITER OUTPUT VOLTAGE. AN AUTOMATIC REGULATOR UNIT IS PROVIDED FOR REGULATING EXCITER FIELD CURRENT TO PROVIDE CONSTANT GENERATOR OUTPUT VOLTAGE. THE AUTOMATIC REGULATOR UNIT, WHICH INCLUDES A NON-LINEAR RATE FEEDBACK LOOP, INCLUDES SEVERAL REGULATORS, EACH RESPONSIVE TO A PARTICULAR SYSTEM VARIABLE FOR CONTROLLING EXCITER FIELD CURRENT IN ACCORDANCE WITH THAT VARIABLE WHEN ITS VALUE GOES BEYOND CERTAIN PREDETERMINED LIMITS, IN ORDER TO PREVENT SYSTEM FAILURE. THE INDIVIDUAL REGULATORS ARE CONNECTED TO CONTROL THE RECTIFIER UNIT THROUGH AN ANALOG OR-GATE WHICH PASSES ONLY THAT REGULATOR OUTPUT SIGNAL HAVING THE GREATEST AMPLITUDE. THE REGULATORS IN THE AUTOMATIC REGULATOR UNIT ARE: (1) THE MAIN CONTROL REGULATOR, (2) THE UNDERVOLTAGE LIMIT REGULATOR, (3) THE CURRENT LIMIT REGULATOR, (4) THE UNDEREXCITED REACTIVE CURRENT LIMIT REGULATOR, AND (5) THE PHASE-BACK LIMIT REGULATOR. FOR PREVENTING COLLAPSE OF EXCITER SELF-EXCITATION, A CURRENT BOOST RECTIFIER UNIT IS PROVIDED FOR MAINTAINING MINIMUM EXCITER FIELD CURRENT UNDER PREDETERMINED CONDITIONS WHICH OTHERWISE MIGHT RESULT IN SUCH COLLAPSE. PARTICULARLY HIGH RELIABILITY IS ACHIEVED BY PROVIDING TWO INDEPENDENT EXCITER FIELD CURRENT SUPPLIED AND BY PROVIDING A SELECTIVE FAILURE CIRCUIT FOR PREVENTING FAILURE IN ONE SUCH SUPPLY FROM ADVERSELY AFFECTING THE OTHER.

Inventors

• 👤 Edward H Dinger

Bibliographic Details