THYRISTOR ASYNCHRONOUS DRIVE Russian patent published in 1998 - IPC

FIELD: control of electric drive speed. SUBSTANCE: thyristor asynchronous drive uses a short-circuiting switch and a short-circuit switching unit connected to the drive units. Contactless change-over of the electric motor is ensured first to the short-circuit operation and back without current inrushes due to synchronization of the supply line and motor emf, and switching-on of the motor first to the line voltage amplitude and then to the third phase voltage amplitude. EFFECT: enhanced reliability, expanded functional abilities of the electric drive. 2 wdgr