METHOD FOR CONTROLLING DC MOTOR FIELD FLUX Russian patent published in 2000 - IPC

FIELD: DC dual speed control thyristor drives for shock-load equipment including continuous hot-rolling mills. SUBSTANCE: controlled variable of field circuit causing reduction in motor field flux is set below rated value. Upon occurrence of shock load with electric drive operating at reduced field flux mentioned variable is increased to rated value. Assumed as field-circuit controlled variable is rectified electromotive force of thyristor converter and desired value of rectified electromotive force dictating reduction of motor field flux is found from specified dependence; aperiodic second- order law is used for raising field-circuit controlled variable to rated level. EFFECT: improved power characteristics at desired reliability and dynamic characteristics in harnessing shock loads. 4 dwg