Patent GB-1402915-A (GB)
Title: Propulsion system for an automatic transport network using track-bound vehicles
IPC: B61L23/00
Filed: 1972-06-12
Abstract: 1402915 Control of D.C. motors KIEPE ELECTRIC AG 12 June 1972 [15 July 1971] 27384/72 Heading H2J [Also in Division B7] An automatic transport system comprises track-bound automatically-controlled electrically-driven vehicles running between stations where passengers can alight from and board the vehicles, each vehicle S being driven and braked by a D.C. traction motor whose armature 2 is supplied with D.C. from contact lines OV or MN alongside the track and whose field winding 3 is supplied from a battery 1 on the vehicle, the contact lines being divided into electrically isolated sections serving either to supply power to or brake the motor, each power-supplying section being fed by a stationary silicon controlled rectifier unit and those sections associated with a station being divided into braking sections on the entry side and accelerating sections on the exit side, the braking sections having impedances graduated to ensure that the vehicle is brought substantially to a stop in the final section and the accelerating sections supplying voltages graduated to rise by increments whereby the vehicle leaves the final section at full speed. As shown the braking sections are respectively connected to resistors R1 ... R7 of decreasing ohmic value and the accelerating sections are respectively supplied by SCR units A ... G, each having a pair of anti-parallel connected rectifiers whose firing angle is varied to progressively increase the voltage applied to the motor as it passes through the section, whereby the final voltage of one section is equal to the initial voltage of the next section. Resistors R1 ... R7 may be replaced or augmented by static inverters, electromechanical contactors, individual silicon controlled rectifiers, grid-controlled valves or chopper control, whereby braking is progressively varied in like manner to the acceleration. For running between or past stations, each main line track section i has its contact lines OV supplied by a respective SCR unit H designed to power a predetermined number of vehicles on the section with a constant voltage, controllable from zero in the event of a fault by a voltage regulator similar to the regulator I for the SCR unit A. Master control of the system.-A stationary cybernetic control unit Ky passes instruction signals to the regulators I for units A ... H and to a field controller 9 on each vehicle, transmission to the latter member being by way of a signal line L associated with an antenna 11 on the vehicle. Members L, 11 also serve to transmit signals from the vehicle to the unit Ky, which ensures that all the vehicles are correctly spaced, directed, accelerated and braked. The controller 9 also receives signals from sensers 4, 5 respectively responsive to armature and field current and controls the latter through a regulator 8 so that the motor always operates with the characteristics of a series wound motor. Regulators 1 and 8 are also controlled to produce regenerative braking of the motor through the units A ... H if desired. Controller 9 also receives a further signal 10 providing further control of the braking through regulator 8 to prevent wheel slip. Each station comprises a braking section a, a marshalling section b and an accelerating section c.