Patent US3612971A successfully refreshed from Google Patents.
US3612971A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Static converter with dc intermediate circuit for controlling the speed of a three phase motor
Assignee: Siemens AG
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Filing: 1969-08-27
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Granted: 1971-10-12
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Expires: 1989-08-27
Abstract
Abstract A first controllable converter is connected to an electrical power supply source. A second controllable converter is connected to a three-phase electric motor having stator windings impressed by preenergizing current. At least one smoothing choke for controlling the speed of the motor is connected at one end to the first converter and at the other end to the second converter. A control circuit causes the voltage at the one end of the choke to follow the voltage at the other end of the choke.
Inventors
- 👤 Felix Blaschke
- 👤 Herbert Ripperger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:39
CPC Classifications
H; H02; H02P; H02P27/00; H02P27/04; H02P27/06; H02P23/00; H02P23/0004; H02P2201/00; H02P2201/03; H02P27/047
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
153 words
A device for controlling the speed of a three-phase electric motor operated by an impressed stator current having an electrical power supply source, a converter comprising a first controllable converter on the side of the power supply source and a second controllable converter on the side of the motor, and a DC intermediate circuit including at least one smoothing choke having one end connected to said first converter and another end connected to said second converter, the other end of the smoothing choke having a voltage acting in a positive sense, said device comprising a current regulator for the intermediate circuit current which provides an output voltage; a control unit for providing a control voltage for the first and second converters; means for applying the output voltage of the current regulator to the control unit; and means for applying the voltage at the other end of the smoothing choke to the control unit.
Claim 2
Independent Claim
153 words
A device for controlling the speed of a three-phase electric motor operated by an impressed stator current having an electrical power supply source, a converter comprising a first controllable converter on the side of the power supply source and a second controllable converter on the side of the motor, and a DC intermediate circuit including at least one smoothing choke having one end connected to said first converter and another end connected to said second converter, the other end of the smoothing choke having a voltage acting in a positive sense, said device comprising a current regulator for the intermediate circuit current which provides an output voltage; a control unit for providing a control voltage for the first and second converters; means for applying the output voltage of the current regulator to the control unit; and means for applying the voltage at the other end of the smoothing choke to the control unit.
Claim 3
Dependent Claim
52 words
A device as claimed in claim 1, wherein one end of the smoothing choke has a voltage, and further comprising a regulator connected between the current regulator and the control unit; and means for applying the voltage at the One end of the smoothing choke to the regulator in a feedback sense.
Claim 4
Dependent Claim
101 words
A device as claimed in claim 1, wherein the first converter provides an output voltage and has a control input, and further comprising a function generator connected in the control input of the first converter for linearizing the dependence of the arithmetic median value of the output voltage of said first converter upon the control voltage of the control unit, the function generator comprising an electronic amplifier having an input and an output, feedback path connected between the output and the input of the amplifier and a plurality of biased threshold diodes connected in one of the input and feedback path.
Claim 5
Dependent Claim
23 words
A device as claimed in claim 2, wherein the regulator connected between the current regulator and the control unit is a PI regulator.
References Cited (Backward Citations)
US3344326A
Cited
US3444451A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-11 | 1975-04-12 | 1975-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-11 | 1979-04-12 | 1979-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-11 | 1983-04-12 | 1983-10-12 | $7700.00 | Window Closed / Lapsed |