US3909684A — A-C powered, thyristor-switched electric motors h…

Claim 1

Independent Claim 250 words

A superconducting motor adapted to connect to an N-phase polyphase a-c power system that comprises, in combination: an armature winding having coils connected in a closed-loop configuration; an M-pole superconducting field electromagnetically coupled to the armature winding; switch means comprising N-pairs of switching devices connected to each armature winding node, one device of the pair being adapted to conduct electric current in to each node of the armature winding and the other device of each pair being adapted to conduct electric current out from each node of the armature winding, each swinging-device pair comprising two thyristors connected in an anti-parallel emitter-to-base configuration; and sensing and logic means connected to determine, in part, the switching times of the switching devices, the switching devices being a function, as well, of the instantaneous voltage of the a-c system, switching being timed to cause the armature magnetic axis to lead the field magnetic axis by about 90 electrical degrees thereby to provide a motor that operates directly from an a-c line yet exhibits the speed control characteristic of a separately excited d-c motor, said sensing means comprising position indicator and logic device means connected to control gate signals to the thyristors and to relate gate signals to the relative angular positions of the two magnetic axes, the gate signal to one thyristor of each pair being derived from a line of the polyphase a-c power system and the gate signal to the other thyristor of the same pair being derived for a winding node.

Claim 2

Dependent Claim 250 words

A superconducting motor adapted to connect to an N-phase polyphase a-c power system that comprises, in combination: an armature winding having coils connected in a closed-loop configuration; an M-pole superconducting field electromagnetically coupled to the armature winding; switch means comprising N-pairs of switching devices connected to each armature winding node, one device of the pair being adapted to conduct electric current in to each node of the armature winding and the other device of each pair being adapted to conduct electric current out from each node of the armature winding, each swinging-device pair comprising two thyristors connected in an anti-parallel emitter-to-base configuration; and sensing and logic means connected to determine, in part, the switching times of the switching devices, the switching devices being a function, as well, of the instantaneous voltage of the a-c system, switching being timed to cause the armature magnetic axis to lead the field magnetic axis by about 90 electrical degrees thereby to provide a motor that operates directly from an a-c line yet exhibits the speed control characteristic of a separately excited d-c motor, said sensing means comprising position indicator and logic device means connected to control gate signals to the thyristors and to relate gate signals to the relative angular positions of the two magnetic axes, the gate signal to one thyristor of each pair being derived from a line of the polyphase a-c power system and the gate signal to the other thyristor of the same pair being derived for a winding node.

Claim 3

Dependent Claim 38 words

Apparatus as claimed in claim 1 in which N equals three, in which there are three thyristor pairs connected to each node, and in which the armature comprises at least six coils and, therefore, at least six nodes.

Claim 4

Dependent Claim 56 words

Apparatus as claimed in claim 1 in which the field is on the rotor of the machine and in which the sensing and logic means comprises mechanical position indicator and logic device means connected to control the introduction of gate signals to the thyristors and to relate said introduction to the angular position of the rotor.

Claim 5

Dependent Claim 50 words

Apparatus as claimed in claim 3 in which the mechanical position indicator and logic device means comprises a mechanical logic unit that logically effects switching so as to effect an approximately 90 electrical degree spread between the magnetic axis of the armature and the magnetic axis of the rotor field.

Claim 6

Dependent Claim 53 words

Apparatus as claimed in claim 4 in which the mechanical logic unit comprises logic elements connected to said nodes, further logic elements connected to the gates of the out thyristors, still further logic elements connected to the lines of the polyphase system, and still other elements connected to the gates of the in-thyristors.

Claim 7

Dependent Claim 40 words

Apparatus as claimed in claim 5 in which the logic unit comprises a first conductive element comprising conductive segments equal in number to the number of nodes of the armature and a second condUctive element like said first conductive element.

Claim 8

Dependent Claim 47 words

Apparatus as claimed in claim 6 in which the first conductive element and the second conductive elements are annular in shape and are closely, coaxially spaced from one another and in which a brush bridges the gap between the first conductive element and the second conductive element.

Claim 9

Dependent Claim 84 words

Apparatus as claimed in claim 7 in which the segments of the first conductive element are each connected to gates of the out-thyristors associated with one node of the armature and in which the segments of the second conductive element are each connected to one node, a conductive path from said one node and the gates of the out-thyristors associated with said one node being provided through said brush in a predetermined fashion as the shaft rotates to maintain said 90 electrical degree spread.

Claim 10

Dependent Claim 156 words

Apparatus as claimed in claim 8 that also includes N pairs of additional annular-shaped, conductive elements that function in pairs, one element of each pair of additional elements being a solid ring conductor that is connected to each of the N line phases and the other element of each pair of additional elements comprising a plurality of conductive segments disposed in the form of an annulus and whose number equals the number of nodes in the armature winding, the segments of each pair of additional elements being connected to the gates of the in-thyristors of one thyristor pair associated with each node, the elements of each pair of additional elements being closely axially spaced from one another, the apparatus including a brush associated with each pair of additional elements and bridging the gap therebetween thereby to provide a conductive path between a line phase and the gates of the in-thyristor associated with the particular winding node.

Claim 11

Dependent Claim 65 words

Apparatus as claimed in claim 9 in which the first named brush and each of the second-named brushes is replaced by a pair of brushes, each pair performing the function of the individual brush replaced, each brush of each pair being mechanically displaced from one another and being novable simultaneously toward or away from one another to effect changes in the speed of the motor.

Claim 12

Dependent Claim 120 words

Apparatus as claimed in claim 1 in which the field is on the rotor and in which the sensing and logic means acts to render active devices of the switch means operable to carry current in to a pair of nodes separated from one another by one or more coils and to render active devices of the switch means operable to carry current out from a pair of nodes separated 180 electrical degrees from the respective in nodes, thereby to separate the armature into current-carrying coil groups and non-current-carrying coil groups and to affect the speed of the motor on the basis of the ratio of the time average extent of the current-carrying coil groups and the non-current-carrying coil groups.

Claim 13

Dependent Claim 40 words

Apparatus as claimed in claim 11 in which the sensing and logic means is adjustable so as to vary the ratio of the time average extent of the current-carrying groups and the non-current-carrying groups to permit variation in motor speed.

Claim 14

Dependent Claim 54 words

Apparatus as claimed in claim 12 in which the field is on the rotor of the machine, and in which the sensing and logic means comprises mechanical position indicator and logic device means connected to control the introduction of gate signals to the thyristors and to relate to the angular position of the rotor.

Claim 15

Dependent Claim 97 words

Apparatus as claimed in claim 13 in which the mechanical position indicator comprises logic elements connected to said nodes, further logic elements connected to the gates of the out-thyristors, still further logic elements connected to the lines of the polyphase system, and still other elements connected to the gates of the in-thyristors, the first-hand logic elements, said further logic elements and the said still other logic elements each comprising conductive segments equal in number to the number of nodes in the winding and disposed in an annulAr configuration, and said still further logic elements comprising conductive rings.

Claim 16

Dependent Claim 74 words

Apparatus as claimed in claim 14 having three of said still further logic elements and one of said still other elements associated with each of the three, all of the annular-shaped logic elements units being coaxial and separated slightly from one another to operate in pairs, each pair of units having associated therewith two pairs of brushes bridging the associated pair and movable angularly with respect to one another to vary the motor speed.

Claim 17

Dependent Claim 215 words

A variable-speed rotary electric machine for connection to an N-phase polyphase power system that comprises, in combination: an armature winding having an even number of coils connected in a closed-loop configuration; an M-pole field electromagnetically coupled to the armature winding; switch means comprising N-pairs of thyristors connected to each armature winding node, one thyristor of each pair of conducting electric current to each armature winding node and the other thyristor of each pair conducting electric current away from each armature winding node; and sensing and logic means connected to determine, in part, the state of conduction of the thyristor pairs, thereby to determine the direction of electric current flow in each of the armature coils, said sensing means comprising angular position indicator and logic device means connected to control gate signals to the thyristors and to relate said gate signals to the relative angular positions of the magnetic fields of the armature and the M-pole field, the gate of one thyristor of each pair being adapted to connect to an incoming line of the polyphase power system to derive a gate signal from said incoming line and the gate of the other thyristor of the same pair being connected to its associated armature winding node to derive a gate signal from said associated winding node.

Claim 18

Dependent Claim 215 words

A variable-speed rotary electric machine for connection to an N-phase polyphase power system that comprises, in combination: an armature winding having an even number of coils connected in a closed-loop configuration; an M-pole field electromagnetically coupled to the armature winding; switch means comprising N-pairs of thyristors connected to each armature winding node, one thyristor of each pair of conducting electric current to each armature winding node and the other thyristor of each pair conducting electric current away from each armature winding node; and sensing and logic means connected to determine, in part, the state of conduction of the thyristor pairs, thereby to determine the direction of electric current flow in each of the armature coils, said sensing means comprising angular position indicator and logic device means connected to control gate signals to the thyristors and to relate said gate signals to the relative angular positions of the magnetic fields of the armature and the M-pole field, the gate of one thyristor of each pair being adapted to connect to an incoming line of the polyphase power system to derive a gate signal from said incoming line and the gate of the other thyristor of the same pair being connected to its associated armature winding node to derive a gate signal from said associated winding node.

Claim 19

Dependent Claim 15 words

Apparatus as claimed in claim 16 in which the field is an M-pole salient-pole field.

Claim 20

Dependent Claim 153 words

A superconducting motor adapted to connect to an N-phase polyphase a-c power system that comprises, in combination: an armature comprising N single-phase windings each having coils connected in a closed-loop configuration and mechanically staggered from one another by 1/N of a coil width; an M-pole d-c field electromagnetically coupled to the N armature windings; switch means comprising N-pairs of switching devices connected to each armature winding node, one device of the pair acting to conduct electric currents into each node of the armature winding and the other device of each pair acting to conduct electric current out from each node of the armature winding; and sensing means connected to determine, in part, the state of conduction of the switch-device pairs to determine the direction of electric current in each of the coils of the N single-phase windings, the switching times being a function, as well, of the instantaneous voltage of the a-c system.

Claim 21

Dependent Claim 153 words

A superconducting motor adapted to connect to an N-phase polyphase a-c power system that comprises, in combination: an armature comprising N single-phase windings each having coils connected in a closed-loop configuration and mechanically staggered from one another by 1/N of a coil width; an M-pole d-c field electromagnetically coupled to the N armature windings; switch means comprising N-pairs of switching devices connected to each armature winding node, one device of the pair acting to conduct electric currents into each node of the armature winding and the other device of each pair acting to conduct electric current out from each node of the armature winding; and sensing means connected to determine, in part, the state of conduction of the switch-device pairs to determine the direction of electric current in each of the coils of the N single-phase windings, the switching times being a function, as well, of the instantaneous voltage of the a-c system.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-09-29	1979-03-31	1979-09-30	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-09-29	1983-03-31	1983-09-30	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-09-29	1987-03-31	1987-09-30	$7700.00	Window Closed / Lapsed

A-C powered, thyristor-switched electric motors having superconducting fields

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