Electric propulsion and braking system for automotive vehicles
First Claim
1. 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.
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Accused Products
Abstract
An electric propulsion and braking system which includes a plurality of high-speed, dc commutatorless motors each coupled to a wheel of an automotive vehicle through an associated fixed-ratio mechanical transmission. Each motor includes a field winding, an armature winding, and a commutation circuit for the armature winding. During propulsion, each commutation circuit is enabled and, during braking, each commutation circuit is disabled. Control of the amount of propulsion and braking is afforded by varying the dc source voltage across each commutation circuit and by varying the field current in each field winding. The dc source voltage across each commutation circuit is varied by connecting the commutation circuits and a plurality of main electrical energy sources in selected series, series/parallel, and parallel combinations. The field current in each field winding is varied by connecting the field windings with an auxiliary electrical energy source in selected series, series/parallel and parallel combinations, and by duty-cycling the selected combination. The various series, series/parallel and parallel combinations are selected by, and the duty-cycling of the selected field winding combination is controlled by, a microprocessor receiving signals representing the magnitude of electrical energy transfer between the main electrical energy sources and the motors, the position of an acceleration pedal, the position of a brake pedal, the velocity of the vehicle, the dc source voltage across each commutation circuit, and the armature voltage across each armature winding.
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Citations
35 Claims
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1. An electric propulsion and braking system for an automotive vehicle having a plurality of wheels, said system comprising:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. An electric propulsion and braking system for an automotive vehicle having a plurality of wheels, said system comprising:
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a plurality of high-speed, dc motors, each of said motors including a rotatable output shaft, an armature winding, a field winding that is adapted for excitation separate from excitation of said armature winding, and a commutation circuit coupled with said armature winding, said commutation circuit having a pair of terminals and being adapted, when enabled, to commutate a dc source voltage applied across the pair of terminals of said commutation circuit so as to develop an armature voltage across said armature winding to accordingly enable transfer of electrical energy to said armature winding, whereby said motor exerts a rotational force on said output shaft, said commutation circuit being adapted, when disabled, to couple the armature voltage across said armature winding to said pair of terminals of said commutation circuit so as to enable transfer of electrical energy from said armature winding, whereby said motor exerts a braking force on said output shaft when said armature voltage exceeds the dc source voltage applied across said pair of terminals of said commutation circuit, the magnitude of said rotational and braking forces being dependent on the magnitude of the dc source voltage across said commutation circuit and the magnitude of field current through said field winding; a plurality of fixed-ratio mechanical transmissions each being adapted to couple the output shaft of one of said plurality of motors to one of the plurality of wheels; first control means including a plurality of main electrical energy sources for applying, in response to a first control signal, one of a plurality of dc source voltages to said pair of terminals of each of said commutation circuits, each said dc source voltage having a predetermined magnitude which represents a gear of the vehicle and which differs from the predetermined magnitude of each other said dc source voltage; second control means including an auxiliary energy source for varying, in response to a second control signal, the field current in each said field winding; and third control means for enabling propulsion and braking by respectively enabling and disabling said commutation circuits, and for varying the level of rotational and braking forces developed during propulsion and braking by providing said first and said second control signals to said first and said second control means, respectively. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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Specification