Nuclear reactor control rod drive - with adjustable ac feed,dc locking and dynamic braking

摘要

A motor which drives the control rods of a nuclear reactor through a rope drive develops a counter torque which allows the rope to unwind from the pulley at a controlled rate. The motor, with a permanent magnet rotor and a wound stator, is fed an A.C voltage of adjust able amplitude to move the control rods up or down. In case of scram shut-offs this voltage is cut off, and resistors are connected in parallel to the stator, to brake the winch system dynamically.