Electronic controller for electrically-propelled vehicle - uses power transistor chopper circuit with rheostatic braking and thyristor reversible field supply

摘要

The electronic drive circuit uses a separately excited DC motor with the armature (I) supplied by a step-up/step-down chopper circuit. A rheostatic braking circuit a field inversion circuit are also incorporated. The chopper circuit has a first switching transistor (TR1) with a reverse diode (D2) connected in series across the DC supply line. A second power transistor (TR2) is connected via a split inductor (L1,L2) to the emitter of the first transistor (TR1) and through a reverse diode to the positive supply. The motor armature (I) is supplied from the mid-point (7) of the split inductor. An electronic controller circuit (E) determines the switching of the chopper transistors (TR1,TR2) and also the rheostatic braking transistor (TR4). The same controller switches a thyristor converter (T5-T8) to determine the direction of field (J) current.