GB523592A - Improvements in and relating to regenerative braking on electrically driven vehicles - Google Patents

Abstract

523,592. Control of D.C. motors. MALEY, A. W., and TAUNTON, E. M. Oct. 7, 1938, No. 29119. [Class 38 (iii)] Regenerative braking.-In traction equipment the armature circuit is opened should regeneration cease and motoring recommence due, for example, to the vehicle running on to a section of higher supply voltage. With the circuit-breaker 14 closed and the power controller " off," contacts 12 closed, regeneration is initiated by a braking controller closing contacts 13, thereby closing contactors 18, 19. The motor field 3, 4 are thus pre-excited from the supply through a resistance 21. When the voltage across the armatures 1 and 2 approaches that of the supply, contactors 9, 25 close, contactor 25 connects the fields across armature 2, and contactor 9 connects coil 7 and rectifier 8 between armature 1 and the supply. When the back E.M.F. of the motors exceeds the voltage of the supply, coil 7 is energized and contactor 5 closes the regenerative circuit, and is maintained by coil 6. Should at any time the motor armature current reverse, coil 26 in series with a rectifier 23 is energized, causing switch 15 to reverse, thereby not only de-energizing contactors 18, 19, but also energizing trip coil 27 of the circuit breaker 14. The coil 26 may itself be the trip coil of the circuit breaker 14. Specifications 430,029, 434,189, 458,132, 461,881 and 500,947 are referred to.