US3584276A — Vehicle electric motor drive system

Claim 1

Independent Claim 257 words

An electric drive providing constant output power over a speed range and adapted to be energized from an alternating current source comprising, in combination, a synchronous electric motor having a stator winding, a rotor, and means for generating magnetic poles in said rotor, means for generating a speed signal which is a function of the speed of said motor, first function generating means responsive to said speed signal for deriving a first alternating signal in accordance with one of the rectangular coordinates of a variable parameter curve whose parameter is speed of said motor and whose radius vector and vectorial angle polar coordinates are the magnitude and phase angle of the terminal voltage to be applied to said stator winding to keep said magnetic poles on said rotor locked in with the rotating magnetic field generated by said stator winding over said speed range, second function generating means responsive to said speed signal for deriving a second alternating signal in accordance with the other rectangular coordinate of said curve, vector adder means operatively connected to said motor for vectorially adding said first and second signals and generating an output signal whose magnitude is the vector sum and whose phase angle is a function of the quotient of said first and second alternating signals and for modulating said output signal at a frequency which is a function of the speed of said motor, means for demodulating said output signal, and a frequency converter between said alternating current source and stator winding and controlled by the demodulated output signal.

Claim 2

Dependent Claim 257 words

An electric drive providing constant output power over a speed range and adapted to be energized from an alternating current source comprising, in combination, a synchronous electric motor having a stator winding, a rotor, and means for generating magnetic poles in said rotor, means for generating a speed signal which is a function of the speed of said motor, first function generating means responsive to said speed signal for deriving a first alternating signal in accordance with one of the rectangular coordinates of a variable parameter curve whose parameter is speed of said motor and whose radius vector and vectorial angle polar coordinates are the magnitude and phase angle of the terminal voltage to be applied to said stator winding to keep said magnetic poles on said rotor locked in with the rotating magnetic field generated by said stator winding over said speed range, second function generating means responsive to said speed signal for deriving a second alternating signal in accordance with the other rectangular coordinate of said curve, vector adder means operatively connected to said motor for vectorially adding said first and second signals and generating an output signal whose magnitude is the vector sum and whose phase angle is a function of the quotient of said first and second alternating signals and for modulating said output signal at a frequency which is a function of the speed of said motor, means for demodulating said output signal, and a frequency converter between said alternating current source and stator winding and controlled by the demodulated output signal.

Claim 3

Dependent Claim 76 words

An electric drive in accordance with claim 1 wherein said vector adder means is a rotary inductor and has displaced first and second energizing windings coupled to said first and second function generating means respectively, an output winding inductively linked to said energizing windings and in which said output signal is induced, and rotor means operatively connected to the motor rotor for cyclically varying the flux linkage between said energizing and output windings as it rotates.

Claim 4

Dependent Claim 206 words

An electric drive in accordance with claim 1 wherein the variable parameter of said curve has a coefficient and said motor has a plurality of said curves all of which are of the same shape but each of which has a different coefficient for said parameter and represents a different output power from said motor, and wherein the radius vector and vectorial angle polar coordinates of each of said curves are the magnitude and phase angle of the terminal voltage to be applied to said motor stator winding to keep said magnetic poles on said rotor locked in with the rotating magnEtic field generated by said stator winding over the speed range for the output power represented by said curve, and including means for selectively generating a power signal which is a function of the desired power output from said motor, wherein said first and second function generating means are also responsive to said power signal and vary said first and second alternating signals as functions of said power signal, and wherein said means for generating magnetic poles on said motor rotor includes a field winding and also including means for applying a voltage to said field winding which is a function of said power signal.

Claim 5

Dependent Claim 89 words

An electric drive in accordance with claim 1 wherein said second function generating means includes means responsive to said speed signal for deriving a third signal which is a function of the radius vector polar coordinate of said curve, means for deriving a fourth signal which is the vector sum of said first and second alternating signals, and means for comparing said third and fourth signals, the output of said comparing means being said second alternating signal which is in accordance with said other rectangular coordinate of said curve.

Claim 6

Dependent Claim 77 words

An electric drive in accordance with claim 4 wherein said first function generating means includes means responsive to said speed signal for deriving a first DC signal in accordance with said one rectangular coordinate of said curve, means for generating a carrier signal, and a first modulator coupled to said carrier signal generating means and to said first DC signal deriving means for varying the magnitude of said carrier signal in accordance with said first DC signal.

Claim 7

Dependent Claim 133 words

An electric drive in accordance with claim 5 wherein said second function generating means includes means responsive to said speed signal for deriving a second DC signal which is a function of the radius vector polar coordinate of said curve, means for vectorially adding said first and second alternating signals to produce a resultant signal, means for rectifying said resultant signal, means for comparing said second DC signal with the rectified signal from said rectifying means to derive a difference signal, and a second modulator coupled to said carrier signal generating means and to said comparing means for varying the magnitude of said carrier signal in accordance with said difference signal, whereby the output from said second modulator is said second alternating signal in accordance with the other rectangular coordinate of said curve.

Claim 8

Dependent Claim 85 words

An electric drive in accordance with claim 6 wherein said vector adder means is a rotary inductor and has first and second energizing windings in quadrature coupled to said first and second function generating means respectively, an output winding inductively linked to said energizing windings in which said output signal is induced, and ferromagnetic rotor means operatively connected to said motor rotor for modulating the flux linkage between said energizing and output windings as a function of the speed of said motor as it rotates.

Claim 9

Dependent Claim 43 words

An electric drive in accordance with claim 7 wherein said means for vectorially adding includes means for shifting the phase of said second alternating signal 90*, and means for summing the output signal from said phase shifting means and said first alternating signal.

Claim 10

Dependent Claim 172 words

An electric drive in accordance with claim 7 wherein said motor has a plurality of said variable parameter curves in which motor speed is the variable parameter and said parameter has a coefficient and all of said curves are of the same shape and each curve has a different coefficient for said parameter and represents a different power output from said motor, the radius vector and vectorial angle polar coordinates of each said curve being the magnitude and phase angle of the terminal voltage to be applied to said stator winding to keep said magnetic poles on said motor rotor locked in with the rotating magnetic field Generated by said stator winding over the speed range for the motor output power represented by said curve, and including means for selectively deriving a power signal which is representative of said coefficient and the desired power output from said motor; said means for deriving said first DC signal and said means for deriving said second DC signal also being responsive to said power signal.

Claim 11

Dependent Claim 48 words

An electric drive in accordance with claim 9 wherein said means for generating magnetic poles on said motor rotor includes a field winding on the stator of said motor and including means for applying to said field winding a voltage which is a function of said power signal.

Claim 12

Dependent Claim 72 words

An electric drive in accordance with claim 2 wherein said rotary inductor, vector adder means includes a ferromagnetic stator having radially extending teeth and said first and second energizing windings and said output winding have turns encircling said teeth and said ferromagnetic rotor means revolves within said ferromagnetic stator and cyclically modulates the permeances of the paths for the magnetic fluxes generated in said teeth by said turns of said energizing windings.

Claim 13

Dependent Claim 79 words

An electric drive in accordance with claim 3 wherein said first and second function generating means derive first and second in-phase alternating signals which increase approximately equally as a function of said speed signal from zero motor speed up to the base speed at the lower limit of said speed range and whose magnitude is proportional to said power signal, whereby the phase angle of said output signal is substantially constant from zero motor speed to said base speed.

Claim 14

Dependent Claim 84 words

An electric drive in accordance with claim 12 wherein said first and second function generating means derive first and second in-phase alternating signals which vary in opposite directions in accordance with said speed signal from said base speed up to a higher predetermined motor speed and which maintain said output signal constant for a selected power signal over said speed range, whereby the phase of said output signal varies as a function of motor speed from said base speed to said higher predetermined speed.

Claim 15

Dependent Claim 48 words

An electric drive in accordance with claim 6 wherein said means for deriving a second DC signal generates a signal which varies linearly with motor speed from zero speed to said base speed and has a fixed magnitude proportional to said power signal over said motor speed range.

Claim 16

Dependent Claim 51 words

An electric drive in accordance with claim 8 and including first switching means for selectively reversing the energization of said second energizing winding, whereby the phase of the voltage supplied by said frequency converter to said stator winding is shifted to control the direction of rotation or torque of said motor.

Claim 17

Dependent Claim 66 words

An electric drive in accordance with claim 15 and including second switching means for selectively reversing the energization of said first energizing winding, whereby the displacement angle between said magnetic poles on said motor rotor and said magnetic field generated by said motor stator winding is changed from positive to negative and said motor is regeneratively braked when said first and second switching means are operated.

Claim 18

Dependent Claim 60 words

An electric drive in accordance with claim 3 wherein said motor rotor is solid and ferromagnetic and has circumferentially spaced salient pole portions forming low reluctance airgaps with the motor stator and wherein said salient pole portions are also spaced axially and said field winding generates axially spaced magnetic poles of opposite polarity in said axially spaced salient pole portions.

Claim 19

Dependent Claim 75 words

An electric drive in accordance with claim 11 wherein said rotary inductor ferromagnetic stator has first and second radially extending teeth displaced ninety electrical degrees apart surrounded respectively by turns of said first and second energizing windings and wherein serially connected turns of said output winding surround both said first and said second teeth and said ferromagneTic rotor means has a lobe and varies sinusoidally the airgap between it and said teeth as it rotates.

Claim 20

Dependent Claim 74 words

An electric drive in accordance with claim 2 and including means for supplying a signal to one of said energizing windings at zero speed of said motor having a magnitude which is a function of said power signal and which decreases as a function of said speed signal as said motor accelerates from zero speed to the base speed at the lower limit of said speed range, whereby motor torque is available at starting.

Claim 21

Dependent Claim 96 words

The electric drive of claim 2 wherein said source of alternating current, said motor stator winding, said demodulating means and said output winding of said rotary inductor, vector adder means are polyphase and wherein said frequency converter is a cycloconverter and includes a set of controlled rectifiers between each phase of said stator winding and said alternating current source, each said set including a pair of oppositely-poled rectifiers connected to each phase of said source, and also including firing circuit means controlled by said polyphase demodulated output signal for deriving gating signals for said controlled rectifiers.

Claim 22

Dependent Claim 62 words

The electric drive of claim 20 wherein said firing circuit means includes means for deriving reference signals which are functions of the phase voltages of said alternating current source, means for combining said reference signals and the phase demodulated output signals to derive composite sequence signals, and means controlled by said sequence signals for deriving said gating signals for said controlled rectifiers.

Claim 23

Dependent Claim 117 words

An electric drive in accordance with claim 20 wherein said rotary inductor output winding includes n phase output windings displaced 360/n degrees apart and said rotor means sinusoidally modulates the flux linkages between said energizing and phase output windings as it revolves, said demodulating means receive the output signals induced in said phase output windings to derive demodulated phase output signals, and including means for deriving reference signals which are functions of the phase voltages of said source, and wherein said firing circuit means includes means for superimposing said demodulated phase output signals and said reference signals to derive composite sequence signals and means controlled by said sequence signals for generating gating signals for said controlled rectifiers.

Claim 24

Dependent Claim 42 words

An electric drive in accordance with claim 22 and including clipping circuit means between said demodulating means and said firing circuit means for limiting the amplitude of said demodulated phase output signals, whereby the voltage rating of said controlled rectifiers is reduced.

Claim 25

Dependent Claim 84 words

An electric drive in accordance with claim 23 wherein said cycloconverter includes a reactor having a midtap between each phase of said motor stator winding and each set of controlled rectifiers and wherein the anodes of all the controlled rectifiers of each said set having one polarity are commoned and connected to one end of said reactor and the cathodes of all of the controlled rectifiers of said set having the oppositely polarity are commoned and connected to the opposite end of said reactor.

Claim 26

Dependent Claim 108 words

An electric drive in accordance with claim 22 wherein said gating signal generating means includes a plurality of zero voltage crossing detecting means associated with each said set of controlled rectifiers and each of said zero crossing detecting means receives one of said sequence signals as an input, and a plurality of means, each of which is controlled by one of said zero voltage crossing detecting means, for deriving gating signals for one of said pair of oppositely poled rectifiers which one pair is connected to a phase of said source different than the phase from which the sequence signal input to the corresponding detecting means was derived.

Claim 27

Dependent Claim 118 words

An electric drive in accordance with claim 25 wherein each said zero crossing detecting means provides first and second outputs when said sequence signaL crosses zero in the positive-going and negative-going directions respectively and each said means for generating gating signals for one of said pair of oppositely poled rectifiers includes first and second flip-flops coupled to said zero crossing detecting means and controlled by said first and second outputs respectively, first and second oscillators controlled by said first and second flip-flops, and means including rectifiers for coupling said first and second oscillators to the gates of said pair of oppositely controlled rectifiers respectively, whereby successive DC firing pulses are applied to the gates of said controlled rectifiers.

Claim 28

Dependent Claim 104 words

An electric drive in accordance with claim 26 wherein all of said first flip-flops are connected as a ring counter and each said first flip-flop associated with one pair of controlled rectifiers is reset by said second output from a zero crossing detecting means associated with a different pair of oppositely poled rectifiers of said set and all of said second flip-flops are connected as a ring counter and each said second flip-flop associated with one pair of controlled rectifiers is reset by said first output from a zero crossing detecting means associated with a different pair of oppositely poled flip-flops of said set.

Claim 29

Dependent Claim 252 words

An electric drive having selectively variable power output levels and providing constant output power over a speed range for each power level and adapted to be energized from a source of alternating current, comprising, in combination: a synchronous electric motor having a stator winding, a rotor, and a field winding for generating magnetic poles in said rotor; means for deriving a speed signal which is a function of the speed of said motor; first function generating means responsive to said speed signal for deriving a first alternating signal in accordance with one parametric equation of a variable parameter curve whose variable parameter is speed of said motor and whose polar coordinates are the magnitude and phase angle of the terminal voltage to be applied to said stator winding to keep said magnetic poles in said rotor locked in with the rotating magnetic field generated by said stator winding over the speed range, second function generating means responsive to said speed signal for deriving a second alternating signal in accordance with the other parametric equation of said curve, vector adder means operatively connected to said motor rotor for deriving an output signal whose magnitude is the vector sum and whose phase angle is a function of the quotient of said first and second alternating signals and for modulating said output signal at a frequency which is a function of the speed of said motor, and a frequency changer connected between said alternating current source and said stator winding controlled by said output signal.

Claim 30

Dependent Claim 252 words

An electric drive having selectively variable power output levels and providing constant output power over a speed range for each power level and adapted to be energized from a source of alternating current, comprising, in combination: a synchronous electric motor having a stator winding, a rotor, and a field winding for generating magnetic poles in said rotor; means for deriving a speed signal which is a function of the speed of said motor; first function generating means responsive to said speed signal for deriving a first alternating signal in accordance with one parametric equation of a variable parameter curve whose variable parameter is speed of said motor and whose polar coordinates are the magnitude and phase angle of the terminal voltage to be applied to said stator winding to keep said magnetic poles in said rotor locked in with the rotating magnetic field generated by said stator winding over the speed range, second function generating means responsive to said speed signal for deriving a second alternating signal in accordance with the other parametric equation of said curve, vector adder means operatively connected to said motor rotor for deriving an output signal whose magnitude is the vector sum and whose phase angle is a function of the quotient of said first and second alternating signals and for modulating said output signal at a frequency which is a function of the speed of said motor, and a frequency changer connected between said alternating current source and said stator winding controlled by said output signal.

Claim 31

Dependent Claim 80 words

An electric drive in accordance with claim 28 wherein said second function generating means includes means responsive to said speed signal for deriving a third signal which is a function of the radius polar coordinate of said curve, means for deriving a fourth signal which is the vector sum of said first and second alternating signals, and means for comparing said third and fourth signals to derive said second alternating signal which is in accordance with said other parametric equation.

Claim 32

Dependent Claim 74 words

An electric drive in accordance with claim 29 wherein said first function generating means includes means responsive to said speed signal for deriving a first DC signal in accordance with said one parametric equation, means for generating a carrier signal, and a first modulator coupled to said carrier signal generating means and to said first DC signal deriving means for varying the amplitude of said carrier signal in accordance with said first DC signal.

Claim 33

Dependent Claim 123 words

An electric drive in accordance with claim 30 wherein said second function generating means includes means responsive to said speed signal for deriving a second DC signal which is a fuNction of the radius polar coordinate of said curve, means for vectorially adding said first and second alternating signals to produce a resultant signal, means for rectifying said resultant signal, means for comparing said second DC signal and the rectified signal from said rectifying means to derive a difference signal, and a second modulator coupled to said carrier signal generating means and to said comparing means for varying the amplitude of said carrier signal in accordance with said difference signal to derive said second alternating signal in accordance with said other parametric equation.

Claim 34

Dependent Claim 81 words

An electric drive in accordance with claim 29 wherein said vector adder means includes a rotary inductor having angularly displaced first and second energizing windings coupled to said first and second function generating means respectively, an output winding inductively linked to said first and second energizing windings in which said output signal is induced, and ferromagnetic rotor means operatively connected to said motor rotor for cyclically varying the flux linkage between said output winding and said energizing windings as it revolves.

Claim 35

Dependent Claim 155 words

An electric drive in accordance with claim 32 wherein said motor has a plurality of said curves each of which represents a different power output from said motor and wherein all of said curves are of the same shape and the radius vector and vectorial angle polar coordinates of each curve are the magnitude and phase angle of the terminal voltage to be applied to said stator winding to keep the output power represented by said curve constant over the speed range and including means for selectively deriving a power signal which is a function of the desired power output from said motor and wherein said first and second function generating means are also responsive to said power signal and vary the magnitude of said first and second alternating signals in accordance with said power signal, and including means for applying a voltage to said field winding which is a function of said power signal.

Claim 36

Dependent Claim 104 words

An electric drive in accordance with claim 32 wherein said rotary inductor vector adder means includes a ferromagnetic stator having first and second teeth angularly displaced apart, said first and second energizing windings have turns which respectively surround said first and second teeth, said output winding has turns surrounding said first tooth connected in series with turns surrounding said second tooth, and said rotor means is disposed adjacent said rotary inductor stator and is rotatable relative thereto and forms a portion of the paths for magnetic fluxes generated in said teeth and cyclically varies the permeances of said magnetic flux paths as it rotates.

Claim 37

Dependent Claim 64 words

An electric drive in accordance with claim 34 wherein said rotor means is a ferromagnetic rotor member having a lobe portion which has the smallest magnetic reluctance gap from said teeth and a dale portion having a greater magnetic reluctance gap from said teeth than said lobe portion and said rotor means sinusoidally varies the permeances of said magnetic flux paths as it rotates.

Claim 38

Dependent Claim 146 words

An electric drive in accordance with claim 35 wherein said rotary inductor stator has a set of said first teeth angularly displaced from each other and a set of said second teeth angularly displaced from each other, said set of first teeth is angularly displaced from said set of second teeth, said first energizing winding has serially connected turns surrounding each of said first teeth and said second energizing winding has serially connected turns surrounding each of said second teeth, and said output winding has serially connected turns surrounding teeth of said first set and teeth of said second set, whereby said output signal induced in said output winding is a function of the magnitude of said first and second signals applied to said first and second energizing windings, the angle between said first and second set of teeth, and the position of said rotor member.

Claim 39

Dependent Claim 40 words

An elEctric drive in accordance with claim 36 wherein said rotary inductor stator is annular, said first and second teeth extend radially inward, and said set of first teeth is displaced 90 electrical degrees from said set of second teeth.

Claim 40

Dependent Claim 73 words

An electric drive in accordance with claim 37 wherein said output winding has turns surrounding a pair of said first teeth angularly displaced 180 electrical degrees apart and arranged in series opposition to cancel the base component of the magnetic flux and connected in series with turns surrounding a pair of said second teeth displaced 180 electrical degrees apart and arranged in series opposition to cancel the base component of the magnetic flux.

Claim 41

Dependent Claim 131 words

An electric drive in accordance with claim 37 wherein said source, said motor stator winding, and said rotary inductor output winding have n phases, said first teeth are angularly displaced 60 electrical degrees apart and said second teeth are displaced 60 electrical degrees apart and positioned between said first teeth, said output winding includes n phase output windings each of which has turns surrounding a pair of said first teeth displaced 180 electrical degrees apart and arranged in series opposition connected in series with turns surrounding a pair of said second teeth displaced 180 electrical degrees apart and arranged in series opposition and wherein said turns of each said phase output winding surround teeth displaced 360/n electrical degrees from the teeth surrounded by the turns of the other phase output windings.

Claim 42

Dependent Claim 82 words

An electric drive in accordance with claim 37 wherein said source, said motor stator winding, and said rotary inductor output winding have n phases and each rotary inductor phase output winding includes turns surrounding one of said first teeth connected in series with turns surrounding one of said second teeth and said one first tooth and said one second tooth are displaced by 360/n electrical degrees from the corresponding teeth surrounded by the turns of the other rotary inductor output phase windings.

Claim 43

Dependent Claim 92 words

An electric drive in accordance with claim 40 wherein each rotary inductor phase output winding has turns surrounding a pair of said first teeth angularly displaced 180 electrical degrees apart and arranged in series opposition connected in series with turns surrounding a pair of said second teeth angularly displaced 180 electrical degrees apart and arranged in series opposition and said pair of first and said pair of second teeth are displaced by 360/n electrical degrees from the pairs of corresponding teeth surrounded by turns of the other rotary inductor phase output windings.

Claim 44

Dependent Claim 114 words

An electric drive in accordance with claim 40 wherein said motor has P poles and said rotary inductor output winding has P/2 pole pairs and each rotary inductor phase output winding includes turns surrounding one of said first teeth in each pole pair connected in series with turns surrounding one of said second teeth in said pole pair and being connected in series with similarly arranged turns surrounding first and second teeth of the other pole pairs, and wherein said rotary inductor rotor means has P/2 lobes with dales between said lobes and sinusoidally varies the permeances of the magnetic flux paths through the teeth in all of said pole pairs as it rotates.

Claim 45

Dependent Claim 111 words

An electric drive having selectively variable power output levels and providing constant output power over a speed range for each power level and adapted to be energized from a source of alternating current comprising, in combination: a synchronous electric motor having a stator winding, a rotor, and means for generating magnetic poles in said rotor; means operatively connected to said rotor for generating an output signal having a frequency which is a function of the speed of said motor; a static frequency changer connected between said source of alternating current anD said stator winding controlled by said output signal; and control means for selectively varying a condition of said output signal.

Claim 46

Dependent Claim 111 words

An electric drive having selectively variable power output levels and providing constant output power over a speed range for each power level and adapted to be energized from a source of alternating current comprising, in combination: a synchronous electric motor having a stator winding, a rotor, and means for generating magnetic poles in said rotor; means operatively connected to said rotor for generating an output signal having a frequency which is a function of the speed of said motor; a static frequency changer connected between said source of alternating current anD said stator winding controlled by said output signal; and control means for selectively varying a condition of said output signal.

Claim 47

Dependent Claim 17 words

The electric drive of claim 43 wherein said control means varies the phase of said output signal.

Claim 48

Dependent Claim 17 words

The electric drive of claim 43 wherein said control means varies the magnitude of said output signal.

Claim 49

Dependent Claim 29 words

The electric drive of claim 45 wherein said control means regulates the magnitude and shifts the phase of said output signal as functions of the speed of said motor.

Claim 50

Dependent Claim 134 words

The electric drive of claim 46 wherein the magnitude and phase angle of the terminal voltage to be applied to said motor stator winding to keep the magnetic poles generated in said rotor locked in with the rotating magnetic field generated by said stator winding over the speed range are the radius vector and vectorial angle polar coordinates of a variable parameter curve having motor speed as the variable parameter and wherein said electric drive includes means for generating a speed signal which is a function of the speed of said motor and said control means is responsive to said speed signal and regulates the magnitude of said output signal in accordance with said radius vector and shifts the phase of said output signal in accordance with said vectorial angle over said speed range.

Claim 51

Dependent Claim 37 words

The electric drive of claim 43 including means for selectively providing a power signal which is a function of the desired power output of said motor and wherein said control means is responsive to said power signal.

Claim 52

Dependent Claim 53 words

The electric drive of claim 48 and including means for generating a speed signal which is a function of the speed of said motor and wherein said control means regulates a condition of said output signal as a function of the magnitude of said power signal and the magnitude of said speed signal.

Claim 53

Dependent Claim 35 words

The electric drive of claim 48 wherein, for a given magnitude of said speed signal, said control means varies the magnitude of said output signal as a function of the magnitude of said power signal.

Claim 54

Dependent Claim 34 words

The electric drive of claim 48 wherein, for a selected magnitude of said power signal, said control means shifts the phase of said output signal as a function of the speed of said motor.

Claim 55

Dependent Claim 30 words

The electric drive of claim 48 wherein said electric motor also has a field winding and including means for energizing said field winding as a function of said power signal.

Claim 56

Dependent Claim 182 words

The electric drive of claim 48 wherein said motor has a plurality of variable parametric curves of the same shape whose parameter is the speed of said motor and each of which represents a different power output from said motor and the radius vector and vectorial polar coordinates of each said curve are the magnitude and phase angle of the terminal voltage to be applied to said stator winding to keep the rotor poles generated in said motor rotor locked in with the rotating magnetic field generated by said stator field, and thus keep the motor power output constant, over the speed range and wherein said electric drive includes means for deriving a speed signal which is a function of the speed of said motor and said control means is responsive to both said speed signal and to said power signal and, for a selected power signal, regulates the magnitude of said output signal and shifts the phase of said output signal in accordance with the radius vector and vectorial angle polar coordinates of the curve corresponding to said selected power signal.

Claim 57

Dependent Claim 58 words

The electric drive of claim 51 wherein, for said selected magnitude of power signal, said control means also maintains the magnitude of said output signal substantially constant from the base speed at the lower limit of the speed range at which constant maximum power is developed by said motor up to the upper limit of said speed range.

Claim 58

Dependent Claim 71 words

The electric drive of claim 43 wherein said means for generating an output signal is a rotary inductor having a primary winding and a secondary winding inductively linked to said primary winding and in whiCh said output signal is induced and said control means includes said primary and secondary windings and shifts the phase and regulates the magnitude of said output signal as a function of the speed of said motor.

Claim 59

Dependent Claim 48 words

The electric drive of claim 55 wherein said rotary inductor means for generating said output signal includes ferromagnetic rotor means operatively connected to said motor rotor for modulating the flux linkage between said primary and secondary windings as said ferromagnetic rotor means is rotated by said motor rotor.

Claim 60

Dependent Claim 31 words

The electric drive of claim 56 wherein said rotary inductor means includes a stator, said rotor means turns within said stator, and said primary and secondary windings are on said stator.

Claim 61

Dependent Claim 28 words

The electric drive of claim 57 wherein said rotor means has a lobe and sinusoidally varies the flux linkage between said primary and secondary windings as it rotates.

Claim 62

Dependent Claim 52 words

The electric drive of claim 56 wherein said rotary inductor means is a vector adder and has a pair of displaced primary windings inductively linked to said secondary winding and said ferromagnetic rotor means cyclically modulates the flux linkage between each of said primary windings and said secondary winding as it rotates.

Claim 63

Dependent Claim 89 words

The electric drive of claim 54 wherein the displacement angle between said magnetic poles on said motor rotor and the magnetic field generated by said motor stator winding varies with motor speed from the base speed at the lower limit of said speed range up to a higher predetermined speed, and wherein said control means shifts the phase of said output signal as a function of the speed of said motor from said base speed to said higher predetermined speed while maintaining the magnitude of said output signal constant.

Claim 64

Dependent Claim 95 words

An electric drive in accordance with claim 49 wherein said alternating current source, said stator winding, and said frequency converter have n phases, said output signal generating means includes means for deriving n phase, alternating output signals modulated at a frequency which is a function of the speed of said motor, and said control means includes a demodulator receiving said phase output signals as an input to derive demodulated output signals and means for regulating the phase and magnitude of said phase output signals as functions of both said speed signal and said power signal.

Claim 65

Dependent Claim 133 words

An electric drive in accordance with claim 43 wherein said alternating current source and said stator winding have n phases, said frequency converter is a cycloconverter and includes a set of controlled rectifiers between each phase of said stator winding and said alternating current source and each set includes a pair of oppositely poled rectifiers connected to each phase of said source, said output signal generating means includes means for deriving n phase output signals having a frequency which is a function of the speed of said motor, and said control means includes means for regulating the phase and magnitude of said phase output signals as a function of the speed of said motor and firing current means controlled by said regulated phase output signals for deriving gating signals for said controlled rectifiers.

Claim 66

Dependent Claim 103 words

An electric drive in accordance with claim 62 wherein said output signal generating means derives n phase, alternating output signals modulated at a frequency which is a function of the speed of said motor and said control means includes discriminator means for demodulating said phase output signals, and said firing circuit means includes means for deriving reference signals which are functions of the phase voltages of said alternating current source, means for combining said reference signals and the demodulated phase output signals to derive composite sequence signals and means controlled by said sequence signals for generating said gating signals for said controlled rectifiers.

Claim 67

Dependent Claim 58 words

An electric drive in accordance with claim 48 wherein said synchronous motor is of the inductor type and said moTor rotor is solid and ferromagnetic and said means for generating magnetic poles in said rotor includes a field winding on said motor stator and including means for energizing said field winding as a function of said power signal.

Claim 68

Dependent Claim 71 words

An electric drive in accordance with claim 64 wherein said motor rotor has circumferentially spaced salient pole portions providing a low reluctance path to the motor stator and chordlike portions between said pole portions forming a high reluctance airgap with said motor stator and said salient pole portions are also axially spaced apart and said field winding generates axially spaced magnetic poles of opposite polarity in said axially spaced pole portions.

Claim 69

Dependent Claim 125 words

An electric drive having selectively variable power output levels and providing constant output power over a speed range for each selected power level and adapted to be energized from a source of alternating current comprising, in combination: a synchronous electric motor having a stator winding, a rotor, and means for generating magnetic poles in said rotor; means operatively connected to said motor rotor for generating an output signal having a frequency which is a function of the speed of said motor, control means for selectively shifting the phase and regulating the magnitude of said output signal as a function of the speed of said motor; and a frequency converter connected between said source of alternating current and said stator winding controlled by said output signal.

Claim 70

Dependent Claim 125 words

An electric drive having selectively variable power output levels and providing constant output power over a speed range for each selected power level and adapted to be energized from a source of alternating current comprising, in combination: a synchronous electric motor having a stator winding, a rotor, and means for generating magnetic poles in said rotor; means operatively connected to said motor rotor for generating an output signal having a frequency which is a function of the speed of said motor, control means for selectively shifting the phase and regulating the magnitude of said output signal as a function of the speed of said motor; and a frequency converter connected between said source of alternating current and said stator winding controlled by said output signal.

Claim 71

Dependent Claim 41 words

An electric drive in accordance with claim 66 wherein said means for generating an output signal is a rotary inductor having an energizing winding and a secondary winding inductively linked to said energizing winding in which said output signal is induced.

Claim 72

Dependent Claim 105 words

An electric drive in accordance with claim 67 wherein said rotary inductor is a vector adder having displaced first and second energizing windings inductively linked to said secondary winding and said control means includes said energizing and secondary windings and vectorially adds first and second signals applied to said first and second energizing windings and induces said output signal in said secondary winding whose magnitude is equal to the vector sum of said first and second signals and whose phase is shifted relative to said first and second signals by an angle which is a function of the ratio of said first and second signals.

Claim 73

Dependent Claim 39 words

An electric drive in accordance with claim 68 wherein said rotary inductor includes ferromagnetic rotor means operatively connected to said motor rotor for cyclically modulating the flux linkage between said secondary winding and said energizing windings as it rotates.

Claim 74

Dependent Claim 67 words

An electric drive in accordance with claim 69 wherein said secondary winding includes first and second serially connected coils and the paths of the magnetic fluxes generated by said first and second energizing windings link said first and second coils respectively and said rotary inductor rotor means is solid and cyclically varies the permeances of said magnetic flux paths as it is revolved by said motor rotor.

Claim 75

Dependent Claim 40 words

An electric drive in accordance with claim 70 wherein said control means includes function generating means for providing in-phase, first and second alternating signals to said first and second energizing windings which are functions of the speed of said motor.

Claim 76

Dependent Claim 127 words

An electric drive in accordance with claim 71 wherein said function generating means provides first and second signals to said first and second energizing windings respectively which vary in the same direction as functions of the speed of said motor from zero speed up to the base speed at the lower limit of said speed range at which maximum constant power is delivered by said motor and which vary in opposite directions as functions of the speed of said motor from said base speed up to a higher predetermined speed, whereby the phase of said output signal is constant from zero speed to said base speed and is varied as a function of thE speed of said motor from said base speed to said higher predetermined speed.

Claim 77

Dependent Claim 93 words

An electric drive in accordance with claim 72 wherein the magnitude and phase angle of the voltage to be applied by said cycloconverter to said stator winding to keep said magnetic poles generated in said motor rotor locked in with the rotating magnetic field generated by said stator winding over said speed range are the polar coordinates of a curve whose variable parameter is the speed of said motor and wherein said function generating means derive in-phase first and second signals in accordance with the x and y parametric equations of said curve.

Claim 78

Dependent Claim 113 words

An electric drive in accordance with claim 71 wherein the displacement angle between said magnetic poles on said motor rotor and the magnetic field generated by said motor stator winding varies with motor speed along a displacement angle versus speed characteristic from the base speed at the lower limit of said speed range up to a higher predetermined speed, and wherein said function generating means provides in-phase first and second alternating signals to said first and second energizing windings which maintain the magnitude of said output signal constant and shift the phase of said output signal in accordance with said characteristic in the range from said base speed to said higher predetermined speed.

Claim 79

Dependent Claim 44 words

An electric drive in accordance with claim 66 wherein said synchronous motor is of the inductor type and said motor rotor is solid and said means for generating magnetic poles in said motor rotor includes a field winding on the stator of said motor.

Claim 80

Dependent Claim 48 words

An electric drive in accordance with claim 75 wherein said motor rotor is of ferromagnetic material and has circumferentially spaced salient pole portions providing a low reluctance path to the motor stator and chordlike portions between said pole portions forming a high reluctance airgap with said motor stator.

Claim 81

Dependent Claim 40 words

An electric drive in accordance with claim 76 wherein said salient pole portions on said motor rotor are also axially spaced apart and said field winding generates axially spaced magnetic poles of opposite polarity in said axially spaced pole portions.

Claim 82

Dependent Claim 101 words

An electric drive in accordance with claim 72 wherein said means for generating magnetic poles on said motor rotor includes a field winding, and including means for selectively deriving a power signal which is proportional to the desired power output level of said motor, means for energizing said field winding as a function of the magnitude of said power signal, and wherein said function generating means is responsive to said power signal and provides in-phase first and second alternating signals to said first and second energizing windings which are functions of both said power signal and the speed of said motor.

Claim 83

Dependent Claim 60 words

An electric drive in accordance with claim 78 wherein said function generating means provides in-phase first and second alternating signals to said first and secondary energizing windings which vary in magnitude as a function of said power signal and which provide a fixed magnitude of said output signal over a speed range for each selected magnitude of said power signal.

Claim 84

Dependent Claim 117 words

An electric drive in accordance with claim 79 wherein said function generating means provides first and second signals to said first and second energizing windings which vary in the same direction as functions of motor speed from zero speed up to the base speed at the lower limit of said speed range and which vary in opposite directions as functions of motor speed from said base speed up to a higher predetermined speed and shift the phase of said output signal as a function of motor speed from said base speed to said higher predetermined speed and maintain the magnitude of said output signal constant over said speed range for each selected magnitude of said power signal.

Claim 85

Dependent Claim 56 words

An electric drive in accordance with claim 80 and including regulating means for providing a signal to one of said energizing windings whOse magnitude is a function of said power signal from zero motor speed to said base speed, whereby said output signal is induced in said secondary winding and motor torque is available at starting.

Claim 86

Dependent Claim 41 words

An electric drive in accordance with claim 81 wherein said regulating means varies the magnitude of said signal to said one energizing winding inversely as a function of motor speed as said motor accelerates from zero speed to said base speed.

Claim 87

Dependent Claim 94 words

An electric drive in accordance with claim 80 wherein the displacement angle between said magnetic poles on said motor rotor and the magnetic field generated by said motor stator winding varies with motor speed up to said higher predetermined speed along a displacement angle versus speed characteristic and wherein said function generating means provides alternating in-phase first and second signals to said first and second energizing windings which vary in opposite directions and shift the phase of said output signal in accordance with said characteristics from said base speed to said higher predetermined speed.

Claim 88

Dependent Claim 49 words

An electric drive in accordance with claim 69 wherein said rotary inductor includes a stator, said energizing windings and said secondary winding are on said stator and said ferromagnetic rotor means is solid and varies the flux linkage between said secondary winding and said energizing windings as it rotates.

Claim 89

Dependent Claim 93 words

An electric drive in accordance with claim 70 wherein said rotary inductor includes a ferromagnetic stator having displaced first and second teeth surrounded respectively by said first and second energizing windings and also surrounded respectively by said first and second coils and wherein said ferromagnetic rotor means is contoured to sinusoidally vary the gap it has with said first and second teeth as it is rotated by said motor rotor, whereby the permeances of the magnetic flux paths through said teeth and into said rotor means are varied as said rotor means revolves.

Claim 90

Dependent Claim 148 words

An electric drive in accordance with claim 68 wherein said rotary inductor includes a ferromagnetic stator having a set of first teeth angularly displaced from each other and a set of second teeth angularly displaced from each other, said set of first teeth is angularly displaced from said set of second teeth, said first energizing winding has serially connected turns surrounding each of said first teeth, said second energizing winding has turns surrounding each of said second teeth connected in series, and said secondary winding has serially connected turns surrounding teeth of said first set and teeth of said second set, whereby said output signal induced in said secondary winding is a function of the magnitude of said first and second signals applied to said first and second energizing windings, the displacement angle between said sets of first and second teeth, and the position of said rotor means.

Claim 91

Dependent Claim 40 words

An electric drive in accordance with claim 86 wherein said rotary inductor stator is annular, said first and second teeth extend radially inward, and said set of first teeth is displaced 90 electrical degrees from said set of second teeth.

Claim 92

Dependent Claim 86 words

An electric drive in accordance with claim 87 wherein said alternating current source and said motor stator winding have n phases and said rotary inductor secondary winding includes n phase output windings each of which includes turns surrounding one of said first teeth connected in series with turns surrounding one of said second teeth and said one first tooth and said one second tooth are displaced by 360/n electrical degrees from the corresponding teeth surrounded by the turns of the other rotary inductor phase output windings.

Claim 93

Dependent Claim 111 words

An electric drive in accordance with claim 88 wherein each said rotary inductor phase output winding has turns surrounding a pair of said first teeth angularly displaced 180 electrical degrees apart and arranged in series opposition to cancel the base component of the magnetic flux connected in series with turns suRrounding a pair of said second teeth angularly displaced 180 electrical degrees apart and arranged in series opposition to cancel the base component of the magnetic flux and said pair of first and said pair of second teeth are displaced by 360/n electrical degrees from the pairs of corresponding teeth surrounded by turns of the other rotary inductor phase output windings.

Claim 94

Dependent Claim 109 words

An electric drive in accordance with claim 78 wherein said alternating current source and said motor stator winding have n phases and said rotary inductor secondary winding includes n phase output windings and said frequency converter is a cycloconverter and includes a set of controlled rectifiers between each phase of said stator winding and said alternating current source with each set including a pair of oppositely poled controlled rectifiers connected to each phase of said source, and wherein said control means includes firing circuit means controlled by the polyphase output signal from said n phase output windings of said rotary inductor for deriving gating signals for said controlled rectifiers.

Claim 95

Dependent Claim 75 words

An electric drive in accordance with claim 90 and including means for deriving reference signals which are functions of the phase voltages of said alternating current source and wherein said firing circuit means includes means for combining said reference signals and the phase output signals from said phase output windings of said rotary inductor to derive composite sequence signals, and means controlled by said sequence signals for deriving said gating signals for said controlled rectifiers.

Claim 96

Dependent Claim 96 words

An electric drive in accordance with claim 90 wherein said rotor means sinusoidally modulates the permeances of said magnetic flux paths, and including discriminator means for demodulating said phase output signals from said rotary inductor phase winding to derive demodulated output signals, means for generating reference signals which are functions of the phase voltages of said source, and wherein said firing circuit means includes means for superimposing said demodulated output signals and said reference signals to derive composite sequence signals, and means controlled by said sequence signals for deriving said gating signals for said controlled rectifiers.

Claim 97

Dependent Claim 43 words

An electric drive in accordance with claim 92 and including clipping circuit means between said discriminator means and said firing circuit means for limiting the amplitude of said demodulated phase output signals, whereby the voltage rating of said controlled rectifiers may be reduced.

Claim 98

Dependent Claim 95 words

An electric drive in accordance with claim 90 wherein said cycloconverter includes a reactor having a midtap between each phase of said motor stator winding and each set of controlled rectifiers, said motor stator phase winding being connected to said midtap, and wherein the anodes of all of the controlled rectifiers of each said set having one polarity are commoned and connected to one end of said reactor and the cathodes of all of the controlled rectifiers of said set having the opposite polarity are commoned and connected to the opposite end of said reactor.

Claim 99

Dependent Claim 112 words

An electric drive in accordance with claim 92 wherein said gating signal deriving means includes a plurality of zero voltage crossing detecting means associated with each said set of controlled rectifiers and each of said zero crossing detecting means receives one of sequence signals as an input, and also including a plurality of means, each of which is controlled by one of said zero voltage detecting crossing means, for deriving gating signals for one of said pairs of oppositely poled controlled rectifiers which one pair is connected to a phase of said alternating current source other than the phase from which the sequence signal input to the corresponding detecting means was derived.

Claim 100

Dependent Claim 123 words

An electric drive in accordance with claim 95 wherein each said zero crossing detecting means provides first and second outputs when said sequence signal input crosSes zero in the positive-going and negative-going directions respectively and each of said means for deriving gating signals for one of said pairs of oppositely poled controlled rectifiers includes first and second flip-flops coupled to said zero crossing detecting means and adapted to be set by said first and second outputs respectively, first and second oscillators controlled by said first and second flip-flops, and rectifier means for coupling said first and second oscillators to the gates of said pair of oppositely-poled controlled rectifiers respectively, whereby successive DC firing pulses are applied to the gates of said controlled rectifiers.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1974-06-07	1974-12-07	1975-06-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1978-06-07	1978-12-07	1979-06-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1982-06-07	1982-12-07	1983-06-08	$7700.00	Window Closed / Lapsed

Vehicle electric motor drive system

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