Drive system with electric motor, for driving a machine, stops motor in event of abnormal conditions by activating both armature short-circuit and mechanical braking

摘要

When the electric motor (EM) cannot be shut down in a regulated manner, both brakes are activated from a set time-point, after which they respond with their immanent dead time (T1,T2). The dead time (T1) of the armature short-circuit brake is less than that (T2) of the mechanical brake. The armature short-circuit is normally ended when the permitted thermal load limits are reached for the electric motor or its drive circuitry (U).