Three-phase, pole-changing motor

Claim 2

A three-phase, alternating-current, speed-changing dynamo electric machine, in which pole-changing is effected by poleamplitude modulation, having a composite three-phase stator winding comprising two similar component windings each with three phase-windings and having the corresponding phase-windings of the component windings connected together as a phase-winding of the composite winding and having corresponding phase-windings of the two component windings spaced apart from each other around the stator winding periphery.

Claim 3

An electric machine as claimed in claim 1, in which pole-changing is effected by an even-cycle, overall modulation wave, each of the two said component windings comprising a substantially balanced three-pHase winding and, in each of the three phase-windings of the composite stator winding, an equal number of coils are reversed in current-carrying sense as the number of coils remaining unchanged, for speed-changing of the machine.

Claim 4

A three-phase, alternating-current, speed-changing dynamo electric machine, in which pole-changing is effected by pole-amplitude modulation, having a composite three-phase stator winding comprising two similar component windings each with three phase-windings and having the corresponding phase-windings of the component windings connected together as a phase-winding of the composite winding and having corresponding phase-windings of the two component windings spaced apart from each other around the stator winding periphery, in which pole-changing is effected by an even-cycle, overall modulation wave, each of the two said component windings comprising a substantially balanced three-phase winding and, in each of the three phase-windings of the composite stator winding, an equal number of coils are reversed in current-carrying sense as the number of coils remaining unchanged, for speed-changing of the machine, and in which each of the two said component windings is made up from three unbalanced winding elements, the three said elements being arranged with corresponding coil groups in the three phases, respectively, of the component winding.

Claim 5

A three-phase, alternating-current, speed-changing dynamo electric machine, in which pole-changing is effected by pole-amplitude modulation, having a composite three-phase stator winding comprising two similar component windings each with three phase-windings and having the corresponding phase-windings of the component windings connected together as a phase-winding of the composite winding and having corresponding phase-windings of the two component windings spaced apart from each other around the stator winding periphery, in which pole-changing is effected by an even-cycle, overall modulation wave, each of the two said component windings comprising a substantially balanced three-phase winding and, in each of the three phase-windings of the composite stator winding, an equal number of coils are reversed in current-carrying sense as the number of coils remaining unchanged, for speed-changing of the machine, and in which each of the two said component windings is made up from three unbalanced winding elements, the three said elements being arranged with corresponding coil groups in the three phases, respectively, of the component winding.

Claim 6

A three-phase, alternating-current, speed-changing dynamo electric machine, in which pole-changing is effected by pole-amplitude modulation, having a composite three-phase stator winding comprising two similar component windings each with three phase-windings and having the corresponding phase-windings of the component windings connected together as a phase-winding of the composite winding and having corresponding phase-windings of the two component windings spaced apart from each other around the stator winding periphery, each of the two said component windings comprising a substantially balanced three-phase winding and, in each of the three phase-windings of the composite stator winding, an equal number of coils being reversible in current-carrying sense as the number of coils remaining unchanged, for speed-changing of the machine, the said composite stator winding being wound in a stator having a slot-number divisible by ''''6'''' and comprising coils of the said two component windings located in alternate slots thereof.

Claim 7

A three-phase, alternating-current, speed-changing dynamo electric machine, in which pole-changing is effected by pole-amplitude modulation, having a composite three-phase stator winding comprising two similar component windings each with three phase-windings and having the corresponding phase-windings of the component windings connected together as a phase-winding of the composite winding and having corresponding phase-windings of the two component windings spaced apart from each other around the stator winding periphery, each of the two said component windings comprising a substantially balanced three-phase winding and, in each of the three phase-windings of the composite stator winding, an equal number of coils being reversible in current-carrying sense as the number of coils remaining unchanged, for speed-changing of the machine, the said composite stator winding being wound in a stator having a slot-number divisible by ''''6'''' and comprising coils of the said two component windings located in alternate slots thereof.

Claim 8

An electric machine as claimed in claim 4, in which corresponding coils of the two component windings are spaced apart around the winding periphery by a uniform number of stator slots substantially equal to a whole number of pole-pitches for both pole-numbers of the machine, an odd number for one pole-number and an even number for the other.

Claim 9

An electric machine as claimed in claim 4, in which corresponding coils of the two component windings are spaced apart by an odd number of stator slots, the slot spacing for the first half of each component winding differing by two slots from the slot spacing for the second half of each component winding.

Claim 10

An electric machine as claimed in claim 4, in which each of the two said component windings is made up from three sub-component windings, the three sub-component windings being arranged with corresponding coil groups in the three phases, respectively, of the component winding and each of the three said sub-component windings is made up from three unbalanced winding elements, the three said elements being arranged with corresponding coils in the three phases, respectively, of the sub-component winding.

Claim 11

An electric machine as claimed in claim 4, in which each of the said two component windings comprises a substantially balanced three-phase, pole-changing winding, corresponding coils of the two component windings being uniformly spaced apart in the composite winding by a number of stator slots which approximates to a single pole-pitch for both the alternative pole-numbers.

Claim 12

An electric machine as claimed in claim 4, in wHich each of the said two component windings comprises a substantially balanced three-phase, pole-changing winding, corresponding coils of the two component windings being uniformly spaced apart in the composite winding by a number of stator slots which is substantially an integral number of pole-pitches for both the alternative pole-numbers, corresponding coils of the two said component windings being energised in the same current-carrying sense when the said integral number is even and being energised in the opposite current-carrying sense when the said integral number is odd.

Claim 13

An electric machine as claimed in claim 4, in which each of the said two component windings comprises a substantially balanced three-phase, pole-changing winding, corresponding coils of the two component windings being uniformly spaced apart in the composite winding by a number of stator slots which is substantially an integral and even number of pole-pitches of an unwanted harmonic pole-number, corresponding coils of the two component windings being energised in opposite current-carrying sense. sense.

Claim 14

A three-phase, alternating-current, speed-changing dynamo electric machine, in which pole-changing is effected by pole-amplitude modulation, having a composite three-phase stator winding comprising two similar component windings each with three phase-windings and having the corresponding phase-windings of the component windings connected together as a phase-winding of the composite winding and having corresponding phase-windings of the two component windings spaced apart from each other around the stator winding periphery, in which each of the said two component windings comprises a substantially balanced three-phase winding in which pole-changing is effected by an odd-cycle overall modulation wave and by six-terminal series/parallel switching of phase-winding parts of the component winding.

Claim 15

A three-phase, alternating-current, speed-changing dynamo electric machine, in which pole-changing is effected by pole-amplitude modulation, having a composite three-phase stator winding comprising two similar component windings each with three phase-windings and having the corresponding phase-windings of the component windings connected together as a phase-winding of the composite winding and having corresponding phase-windings of the two component windings spaced apart from each other around the stator winding periphery, in which each of the said two component windings comprises a substantially balanced three-phase winding in which pole-changing is effected by an odd-cycle overall modulation wave and by six-terminal series/parallel switching of phase-winding parts of the component winding.

Claim 16

A three-phase, alternating-current, speed-changing dynamo electric machine, in which pole-changing is effected by pole-amplitude modulation, having a composite three-phase stator winding comprising two similar component windings each with three phase-windings and having the corresponding phase-windings of the component windings connected together as a phase-winding of the composite winding and having corresponding phase-windings of the two component windings spaced apart from each other around the stator winding periphery, in which each of the said two component windings comprises a substantially balanced three-phase, pole-changing winding, for which an unequal number of coils require to be reversed in current-carrying sense as the number of coils requiring to remain unchanged, for pole-changing, and in which, for speed-changing of the said machine, selected coils of one said component winding are reversed in current-carrying sense whereas the corresponding coils of the other said component windings are not reversed, thereby providing equal numbers of reversed coils and not reversed coils in the said composite winding.

Claim 17

A three-phase, alternating-current, speed-changing dynamo electric machine, in which pole-changing is effected by pole-amplitude modulation, having a composite three-phase stator winding comprising two similar component windings each with three phase-windings and having the corresponding phase-windings of the component windings connected together as a phase-winding of the composite winding and having corresponding phase-windings of the two component windings spaced apart from each other around the stator winding periphery, in which each of the said two component windings comprises a substantially balanced three-phase, pole-changing winding, for which an unequal number of coils require to be reversed in current-carrying sense as the number of coils requiring to remain unchanged, for pole-changing, and in which, for speed-changing of the said machine, selected coils of one said component winding are reversed in current-carrying sense whereas the corresponding coils of the other said component windings are not reversed, thereby providing equal numbers of reversed coils and not reversed coils in the said composite winding.

Claim 18

An electric machine as claimed in claim 4, in which each of the said two component windings comprises a substantially balanced three-phase winding in which pole-changing is effected by an even-cycle overall modulation wave and by six-terminal series/parallel switching of phase-winding parts of the component winding.