EP0093615A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Variable speed rotary electrical machines
Assignee: Garrett Corp
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Filing: 1983-05-03
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Granted: —
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Expires: 2003-05-03
Abstract
Abstract Variable speed rotary electrical machines, specifically induction motors and motor drive systems. A main induction motor (15) and an auxiliary induction motor (17) have respective stators (21) housed in a common housing (19) and have respective rotors (23, 27) which are electrically concatenated and mounted on a common shaft (29). The main stator (21) is supplied with a constant a.c. voltage by a main inverter (35) connected to a constant-voltage d.c. link (45,47, 43) and the auxiliary stator is supplied with a variable a.c. voltage by an auxiliary inventor (37) which is forced-commutated and connected to a variable-voltage d.c. link. A controller (40) controls the gating of the inverters (35, 37) and enables the forced-commutated inverter (37) to supply an a.c. signal of selected frequency and voltage level to the auxiliary stator such that a prescribed reactive power will be coupled through the auxiliary and main rotors (27, 23) to the main stator (21) to cause the latter to appear to constitute a leading power factor load, permitting the main inverter (35) to be line-commutated and supplied from a substantially constant voltage d.c. link. Alternatively, a drive system may comprise a plurality of the machines each with a main motor and an auxiliary motor. The stators of the main machines are all supplied from a single common main inverter which is line-commutated and the stators of the auxiliary machines are separately supplied from separate forced-commutated auxiliary inverters.
Inventors
- 👤 Gabor Kalman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 07:52
CPC Classifications
H; H02; H02K; H02K17/00; H02K17/02; H02K17/34; H02K17/36; H02P; H02P5/00; H02P5/74
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
76 words
A variable speed dynamoelectric induction machine (15) comprising a stator (21) and a rotor (23) referred to as the first-mentioned rotor and co-operating electromagnetically with the stator (21), and characterised by >an inverter (35) connected to the stator (21) and supply means (45,43) connected to the inverter (35) for supplying a substantially constant d.c. voltage thereto and means (17) for providing reactive power to the first-mentioned rotor (23) to permit Line commutation of the inverter (35).
Claim 2
Dependent Claim
76 words
A variable speed dynamoelectric induction machine (15) comprising a stator (21) and a rotor (23) referred to as the first-mentioned rotor and co-operating electromagnetically with the stator (21), and characterised by >an inverter (35) connected to the stator (21) and supply means (45,43) connected to the inverter (35) for supplying a substantially constant d.c. voltage thereto and means (17) for providing reactive power to the first-mentioned rotor (23) to permit Line commutation of the inverter (35).
Claim 3
Dependent Claim
18 words
An induction machine as claimed in CLaim 1 in which the first-mentioned rotor (23) is a squirrel-cage rotor.
Claim 4
Dependent Claim
63 words
An induction machine as claimed in CLaim 1 or CLaim 2, wherein the said means (17) for providing reactive power includes an auxiliary dynamoelectric machine (17) having an auxiliary rotor (27) electrically coupled to the first mentioned rotor (23) and means for developing torque for rotating the auxiliary rotor (27) to cause it to deliver reactive power to the first mentioned rotor (23).
Claim 5
Dependent Claim
59 words
An induction machine as claimed in CLaim 3 in which the auxiliary machine (17) is an induction machine whose rotor (27) is mounted on a common shaft (29) with the first-mentioned rotor (23), and which includes a common housing (19) in which the stators (21 and 25) and rotors ( 23 and 27) of the two machines are housed.
Claim 6
Dependent Claim
36 words
An induction machine as claimed in CLaims 2and 4 in which the rotor (27) of the auxiliary machine (17) is a squirrel-cage rotor whose rotor bars are electrically concatenated with those of the first-mentioned rotor (23).
Claim 7
Dependent Claim
47 words
An induction machine as claimed in any one of the preceding claims wherein the said supply means (45,43) includes a diode rectifier (43) for rectifying the power supplied by a constant-voltage a.c. Line (45) the rectified output of the rectifier (43) being delivered to the inverter (35).
Claim 8
Dependent Claim
45 words
An induction machine as claimed in CLaim 4 or CLaim 5 or in CLaim 6 when dependent on CLaim 4 or CLaim 5, including an auxiliary inverter (37) connected to the stator (25) of the auxiliary machine (17) and supplied from a variabLe-voLtage d.c. supply.
Claim 9
Dependent Claim
166 words
A variable speed induction motor drive system comprising a machine housing (19) a main machine (15) mounted within the machine housing (29), the main machine (15) including a main stator (21) and a main rotor (23) ; and characterised by a main inverter (35) connected to the main stator (21) for supplying electric current thereto, supply means (45,43) connected to the main inverter (35) for supplying a substantially constant d.c. voltage thereto; an auxiliary machine (17) mounted within the machine housing (19) the auxiliary machine (17) including an auxiliary stator (25) and an auxiliary rotor (27), the auxiliary rotor (27) being electrically connected to the main rotor (23) to permit electric current to flow therebetween and an auxiliary inverter (37) connected to the auxiliary stator (25) for supplying electric current thereto, whereby an electric current is induced in the auxiliary rotor (27) said induced current flowing from the auxiliary rotor (27) to the main rotor (23) to produce a voltage for Line-commutating the main inverter (35).
Claim 10
Dependent Claim
166 words
A variable speed induction motor drive system comprising a machine housing (19) a main machine (15) mounted within the machine housing (29), the main machine (15) including a main stator (21) and a main rotor (23) ; and characterised by a main inverter (35) connected to the main stator (21) for supplying electric current thereto, supply means (45,43) connected to the main inverter (35) for supplying a substantially constant d.c. voltage thereto; an auxiliary machine (17) mounted within the machine housing (19) the auxiliary machine (17) including an auxiliary stator (25) and an auxiliary rotor (27), the auxiliary rotor (27) being electrically connected to the main rotor (23) to permit electric current to flow therebetween and an auxiliary inverter (37) connected to the auxiliary stator (25) for supplying electric current thereto, whereby an electric current is induced in the auxiliary rotor (27) said induced current flowing from the auxiliary rotor (27) to the main rotor (23) to produce a voltage for Line-commutating the main inverter (35).
Claim 11
Dependent Claim
41 words
An induction motor drive system as claimed in CLaim 8 wherein the supply means includes an a.c. voltage source (45) to which a diode rectifier (43) is connected for rectifying the a.c. voltage to produce the said substantially constant d.c. voltage.
Claim 12
Dependent Claim
44 words
An induction motor drive system as claimed in CLaim 8 or CLaim 9, wherein the main rotor (23). and the auxiliary rotor (27) are both squirrel-cage rotors, the main inverter (35) is a Line-commutated inverter, and the auxiliary inverter (37) is a forced-commutated inverter.
Claim 13
Dependent Claim
50 words
An induction motor drive system as claimed in any one of CLaims 8-10, further including switch means (47) for disabling the supply means (45,43) curing startup of the induction motor drive system, until the main rotor (21) has reached a speed greater than a prescribed percentage of its maximum speed.
Claim 14
Dependent Claim
66 words
An induction motor drive system as claimed in any one of CLaims 8-11 further including control means (40) for controllably adjusting the respective frequencies of the main and auxiliary inverters (35 and 37) and for controllably adjusting the voltage of the signal supplied to the auxiliary inverter (37) such that the speed of rotation of the main rotor (21) is adjustable over a range of speeds.
Claim 15
Dependent Claim
189 words
A variable speed induction motor drive system characterised by a main inverter (61) supply means (71,69) connected to said main inverter (61) for supplying a substantially constant d.c. voltage thereto; a plurality of main machines each including a main stator (53a,53b) and a main rotor (55a,55b) said main stators (53a, 53b) being connected to the main inverter (61) in parallel with one another; a plurality of auxiliary machines, each auxiliary machine having an auxiliary stator (57a,57b) and an auxiliary rotor (59a,59b) and each auxiliary machine being operatively associated with a separate main machine, with each pair of associated main and auxiliary rotors (55a,59a, and 55b, 59b) being electrically connected together to permit electric current to flow therebetween; a plurality of auxiliary inverters (65a,65b) each being connected to a separate auxiliary,stator (57a,57b) to supply electric current thereto; and a plurality of controllers (67a,67b) each being connected between a separate one of the main rotors (55a,55b) and its associated auxiliary inverter (65a,65b) to controllably adjust the frequencies and voltages of the a.c. signals supplied by the auxiliary inverters (65a,65b) and thereby controLLabLy adjust the speeds of the respective main rotors (55a,55b).
Claim 16
Dependent Claim
189 words
A variable speed induction motor drive system characterised by a main inverter (61) supply means (71,69) connected to said main inverter (61) for supplying a substantially constant d.c. voltage thereto; a plurality of main machines each including a main stator (53a,53b) and a main rotor (55a,55b) said main stators (53a, 53b) being connected to the main inverter (61) in parallel with one another; a plurality of auxiliary machines, each auxiliary machine having an auxiliary stator (57a,57b) and an auxiliary rotor (59a,59b) and each auxiliary machine being operatively associated with a separate main machine, with each pair of associated main and auxiliary rotors (55a,59a, and 55b, 59b) being electrically connected together to permit electric current to flow therebetween; a plurality of auxiliary inverters (65a,65b) each being connected to a separate auxiliary,stator (57a,57b) to supply electric current thereto; and a plurality of controllers (67a,67b) each being connected between a separate one of the main rotors (55a,55b) and its associated auxiliary inverter (65a,65b) to controllably adjust the frequencies and voltages of the a.c. signals supplied by the auxiliary inverters (65a,65b) and thereby controLLabLy adjust the speeds of the respective main rotors (55a,55b).
Claim 17
Independent Claim
64 words
A method for driving a variable speed dynamoelectric induction machine (15) having a squirrel-cage rotor (23), and a stator (21) co-operating electromagnetically with the rotor (23), the method being characterised by the steps of; supplying a substantially constant d.c. voltage to an inverter (35) connected to the stator (21), and delivering reactive power to the squirrel-cage rotor (23) topermit Line commutation of the inverter(35).
Claim 18
Independent Claim
64 words
A method for driving a variable speed dynamoelectric induction machine (15) having a squirrel-cage rotor (23), and a stator (21) co-operating electromagnetically with the rotor (23), the method being characterised by the steps of; supplying a substantially constant d.c. voltage to an inverter (35) connected to the stator (21), and delivering reactive power to the squirrel-cage rotor (23) topermit Line commutation of the inverter(35).
Claim 19
Dependent Claim
53 words
A method as claimed in CLaim 14 wherein said step of delivery reactive power includes a step of developing torque for rotating the rotor (27) of an auxiliary machine (17) said auxiliary machine rotor (27) being electrically coupled to the squirrel-cage rotor (23) whereby reactive power is delivered to the squirrel-cage rotor (23).
Claim 20
Dependent Claim
37 words
A method as claimed in CLaim 14 or CLaim 15, wherein the step of supplying constant d.c. voltage includes a step of rectifying the power supplied by a fixed a.c. Line (45) using a diode rectifier (43).
References Cited (Backward Citations)
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