Electric propulsion and braking system for automotive vehicles

An electric propulsion and braking system for an automotive vehicle having a plurality of wheels, said system comprising:

• a plurality of main electrical energy sources, each said main electrical energy source being adapted to provide a first dc voltage of a predetermined magnitude across a pair of terminals thereof;
• an auxiliary electrical energy source which is adapted to provide a second dc voltage of a predetermined magnitude across a pair of terminals thereof;
• a plurality of high-speed, dc electrical motors, each said motor being associated with one of the plurality of wheels of the vehicle and including:
• a rotor;
• a field winding supported on said rotor, said field winding having a pair of terminals;
• a stator;
• a multiphase armature winding supported on said stator, said armature winding having a plurality of terminals;
• and, a commutation circuit connected to said plurality of terminals of said armature winding, said commutation circuit having a pair of terminals and being operative, when enabled, to commutate a third dc voltage applied to said pair of terminals thereof so as to result in the application of potentials to said plurality of terminals of said armature winding which produce a magnetic field that rotates in substantial synchronism with a magnetic field produced by field current in said field winding, and being operative, when disabled, to couple one of said plurality of terminals of said armature winding to one of said pair of terminals of said commutation circuit whenever the potential on said one of said plurality of terminals of said armature winding that results from a voltage induced in said armature winding by the magnetic field of said field winding exceeds the potential on said one of said pair of terminals of said commutation circuit resulting from the third dc voltage applied to said pair of terminals of said commutation circuit;
• a plurality of transmission means, each said transmission means being adapted to mechanically couple one of said rotors to its associated wheel and having a fixed transmission ratio;
• first means for varying the third dc voltage applied across the pair of terminals of each said commutation circuit, said first means including:
• a positive main bus;
• a negative main bus;
• means coupled to said pair of terminals of each of said plurality of main electrical energy sources for selectively connecting said main electrical energy sources all in series, all in parallel, or in series/parallel with said positive and negative main busses;
• means coupled to said pair of terminals of each of said commutation circuits and responsive to a second control signal for selectively connecting said commutation circuits all in series, all in parallel, or in series/parallel with said positive and negative main busses;
• second means for varying the field current in each said field winding, said second means including:
• a positive auxiliary bus coupled to one of said pair of terminals of said auxiliary electrical energy source;
• a negative auxiliary bus coupled to the other of said pair of terminals of said auxiliary electrical energy source;
• and, means coupled to said pair of terminals of each of said field windings and responsive to a third control signal for selectively connecting said field windings all in series, all in parallel, or in series/parallel with said positive and negative auxiliary busses;
• and,
• third means for enabling propulsion of the vehicle by enabling each said commutation circuit, for enabling braking of the vehicle by disabling each said commutation circuit, and for varying the amount of propulsion and braking by providing said first and second control signals to said first means and said third control signal to said second means.