ES336784A1 - A Traction Drive and Transmission Assembly comprising a Heat Engine and an Electric Transmission - Google Patents

Abstract

A diesel-electric or turbo-electric traction assembly comprises an engine-driven generator 8 supplying at least one traction motor 12, a control device 26 combining the setting of generator speed and generator power output, a control element 16 sensitive to the generator power output, an adjustable control element 32 sensitive to the torque developed by the traction motor and a transducer 18, coupled to the control elements 16, 32, which increases the electric power transmitted to the traction motor when the power does not attain the generator power output set value or the value set by the torque sensitive device or reduces the electric power transmitted to the traction motor when the power exceeds the generator power output set value or the value set by the torque sensitive device. The engine 2, e.g. a diesel or gas turbine engine, has an adjustable speed controller 4 and drives a D.C. generator or alternator 8 which supplies, via a single phase or polyphase power circuit 10, at least one traction motor 12 and auxiliary circuit 14 e.g. feeding a train heating system. The generator can be a permanent magnet type alternator supplying the traction motor via rectifiers or transformers. Supervisory element 16, e.g. an adjustable wattmeter relay, which is sensitive to the generator power output, acts through a mechanical, electrical or pneumatic connection 20 on transducer 18. The output 22 of transducer 18 controls the electrical consumption of the load by acting on one of the parameters e.g. voltage, current, frequency. Thus output 22 may control the excitation of generator 8 or the voltage adjustment of current converter 24 or the system for shunting or varying the torque of each traction motor 12. Speed regulator 4 and supervisory element 8 are conjointly controlled at 26. A manual or automatic element 32, sensitive to traction motor torque acts through connection 34 on system 18 so that the driver can set the maximum tractive effort to avoid wheel slip. The complete system functions so that when any one of the parameters detected by elements 16 or 32 is being exceeded the supervisory element acts on system 18 even though the other supervisory element gives a contradictory instruction. In a preferred means for compensating for the actual instantaneous power and the power theoretically available at the speed set by the speed regulator 4, a relay 38 receives a speed signal from tachometer 46 and a supercharging pressure signal via manometer 50 and acts on supervisory element 16 which in turn is only responsive to the smaller of the two signals it receives (i.e. from conjoint control 26 or relay 38). Operation. The driver operates control 26 to set the speed regulator 4 to a desired speed N and to set element 16 to a desired generator output W. If the power drawn by the traction motors or auxiliaries exceeds W, the element 16 acts on system 18 so that the power drawn by the traction motors decreases until the total power taken is restored to the predetermined value W.