GB470203A - Improvements relating to direct electric current traction equipments arranged for regenerative braking - Google Patents

Abstract

470,203. Control of D,C. motors. GRAY, W. T., and METROPOLITANVICKERS ELECTRICAL CO., Ltd. May 22, 1936, No. 14566. [Class 38 (iii)] Regenerative braking.- In a traction system in which the motors are supplied through a metadyne transformer, and in which provision is made for regenerative braking, a speed sensitive device driven by the train axle is arranged, when the speed falls below a predetermined value, to cut off the excitation of the metadyne and main motors, and also to disconnect the metadyne from the supply, means being provided for rendering the speed sensitive device ineffective during motoring. The speed sensitive device may be a centrifugal device or a generator acting through a relay. The motors may be connected to the metadyne as described in Specification 400,416, and during regeneration master controller segments RC are closed to energize a line switch LS and a switch ES in the circuit of the motor fields and the metadyne variator winding. When the motor speed falls below a predetermined higher speed an auxiliary speed sensitive device closes contacts C1 to energize a coil PB and cause partial application of the mechanical brakes, and when the speed falls to a predetermined lower speed contacts C2 open and contacts C3 close, the switches LS and ES being de-energized and a coil FB energized to effect full application of the mechanical brakes. During motoring contacts IC are effective to open the circuits through contacts C1, C3, and to shunt the contacts C2. Specification 403,464, [Group XXXV], also is referred to.