US5592371A
Expired / Lapsed
US
⏱️ 0.0 years remaining
DC link inverter
Assignee: Motors Liquidation Co
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Filing: 1995-05-17
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Granted: 1997-01-07
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Expires: 2015-05-17
Abstract
Abstract A DC Link for use with a multi-phase DC to AC converter provides soft-switch opportunities to the main inverter devices only when such opportunities are required. A quasi-resonant rail swings from source to ground potential either with or without the assistance of an auxiliary switch. The quasi-resonant rail swings from ground to source potential with the assistance of an auxiliary switch. Low switch stresses are characteristic in both the main inverter switch devices and the DC link switch devices. Main power is carried predominantly through a DC link switch thereby minimizing power handling requirements of DC link reactive components.
Inventors
- 👤 Kaushik Rajashekara
- 👤 Alexander Kurnia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:07
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/4826
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
314 words
A DC link having a DC input and a DC output, the DC input coupled to a DC source and the DC output having substantially a first voltage during power delivery intervals and substantially a second voltage during power interrupt intervals, the DC link comprising: the DC input comprising a positive DC rail at the first voltage and a negative DC rail at the second voltage; the DC output comprising a quasi-resonant rail and the negative DC rail; a first controlled switch connected between the positive DC rail and the quasi-resonant rail; a second controlled switch connected between the negative DC rail and the quasi-resonant rail; first and second diodes, the first diode coupled in anti-parallel across the first controlled switch and the second diode coupled in anti-parallel across the second controlled switch; first and second capacitors, the first capacitor coupled across the first controlled switch and the second capacitor coupled across the second controlled switch; a third diode having an anode and a cathode, said anode coupled to the negative DC rail; an inductor coupled between the cathode of the third diode and the quasi-resonant rail; a third controlled switch coupled between the cathode of the third diode and the positive DC rail; and a DC link control for executing power interrupt intervals intermediate power delivery intervals by sequentially commanding off the first controlled switch to release the quasi-resonant rail from the first voltage to thereby swing the quasi-resonant rail to the second voltage, commanding on the second controlled switch while the second diode is forward biased, commanding on the third controlled switch to catalyze a swing of the quasi-resonant rail to the first voltage, commanding off the second controlled switch to release the quasi-resonant rail from the second voltage to thereby swing the quasi-resonant rail to the first voltage, commanding on the first controlled switch while the first diode is forward biased.
Claim 2
Dependent Claim
314 words
A DC link having a DC input and a DC output, the DC input coupled to a DC source and the DC output having substantially a first voltage during power delivery intervals and substantially a second voltage during power interrupt intervals, the DC link comprising: the DC input comprising a positive DC rail at the first voltage and a negative DC rail at the second voltage; the DC output comprising a quasi-resonant rail and the negative DC rail; a first controlled switch connected between the positive DC rail and the quasi-resonant rail; a second controlled switch connected between the negative DC rail and the quasi-resonant rail; first and second diodes, the first diode coupled in anti-parallel across the first controlled switch and the second diode coupled in anti-parallel across the second controlled switch; first and second capacitors, the first capacitor coupled across the first controlled switch and the second capacitor coupled across the second controlled switch; a third diode having an anode and a cathode, said anode coupled to the negative DC rail; an inductor coupled between the cathode of the third diode and the quasi-resonant rail; a third controlled switch coupled between the cathode of the third diode and the positive DC rail; and a DC link control for executing power interrupt intervals intermediate power delivery intervals by sequentially commanding off the first controlled switch to release the quasi-resonant rail from the first voltage to thereby swing the quasi-resonant rail to the second voltage, commanding on the second controlled switch while the second diode is forward biased, commanding on the third controlled switch to catalyze a swing of the quasi-resonant rail to the first voltage, commanding off the second controlled switch to release the quasi-resonant rail from the second voltage to thereby swing the quasi-resonant rail to the first voltage, commanding on the first controlled switch while the first diode is forward biased.
Claim 3
Dependent Claim
30 words
A DC link as claimed in claim 1 wherein the DC link control further commands off the third controlled switch while the quasi-resonant rail is at substantially the first voltage.
Claim 4
Dependent Claim
67 words
A DC link as claimed in claim 1 further comprising: a fourth controlled switch coupled across the third diode; a fourth diode coupled in anti-parallel across the third controlled switch; and the DC link control further executing power interrupt intervals by commanding on the fourth controlled switch prior to commanding off the first controlled switch to catalyze the swing of the quasi-resonant rail to the second voltage.
Claim 5
Dependent Claim
30 words
A DC link as claimed in claim 3 wherein the DC link control further commands off the fourth controlled switch while the quasi-resonant rail is at substantially the second voltage.
Claim 6
Dependent Claim
353 words
A DC link having a DC input and a DC output, the DC input coupled to a DC source and the DC output coupled to an inverter at an input thereof, said DC output having substantially a first voltage during power delivery intervals and substantially a second voltage during power interrupt intervals, the inverter having a plurality of controlled inverter switches commutated during power interrupt intervals by an inverter control, each controlled inverter switch having an associated anti-parallel diode coupled thereacross, the DC link comprising: the DC input comprising a positive DC rail at the first voltage and a negative DC rail at the second voltage; the DC output comprising a quasi-resonant rail and the negative DC rail; a first controlled switch connected between the positive DC rail and the quasi-resonant rail; a first diode coupled in anti-parallel across the first controlled switch; first and second capacitors, the first capacitor coupled across the first controlled switch and the second capacitor coupled between the quasi-resonant rail and the negative DC rail; a second diode having an anode and a cathode, said anode coupled to the negative DC rail; an inductor coupled between the cathode of the third diode and the quasi-resonant rail; a second controlled switch coupled between the cathode of the second diode and the positive DC rail; and a DC link control for executing power interrupt intervals intermediate power delivery intervals by sequentially commanding off the first controlled switch to release the quasi-resonant rail from the first voltage to thereby swing the quasi-resonant rail to the second voltage, commanding on at least two controlled inverter switches that are coupled in series across the inverter input while the associated anti-parallel diodes are forward biased, commanding on the second controlled switch to catalyze a swing of the quasi-resonant rail to the first voltage, commanding off all of the at least two controlled inverter switches not otherwise commanded on by the inverter control to release the quasi-resonant rail from the second voltage to thereby swing the quasi-resonant rail to the first voltage, commanding on the first controlled switch while the first diode is forward biased.
Claim 7
Dependent Claim
353 words
A DC link having a DC input and a DC output, the DC input coupled to a DC source and the DC output coupled to an inverter at an input thereof, said DC output having substantially a first voltage during power delivery intervals and substantially a second voltage during power interrupt intervals, the inverter having a plurality of controlled inverter switches commutated during power interrupt intervals by an inverter control, each controlled inverter switch having an associated anti-parallel diode coupled thereacross, the DC link comprising: the DC input comprising a positive DC rail at the first voltage and a negative DC rail at the second voltage; the DC output comprising a quasi-resonant rail and the negative DC rail; a first controlled switch connected between the positive DC rail and the quasi-resonant rail; a first diode coupled in anti-parallel across the first controlled switch; first and second capacitors, the first capacitor coupled across the first controlled switch and the second capacitor coupled between the quasi-resonant rail and the negative DC rail; a second diode having an anode and a cathode, said anode coupled to the negative DC rail; an inductor coupled between the cathode of the third diode and the quasi-resonant rail; a second controlled switch coupled between the cathode of the second diode and the positive DC rail; and a DC link control for executing power interrupt intervals intermediate power delivery intervals by sequentially commanding off the first controlled switch to release the quasi-resonant rail from the first voltage to thereby swing the quasi-resonant rail to the second voltage, commanding on at least two controlled inverter switches that are coupled in series across the inverter input while the associated anti-parallel diodes are forward biased, commanding on the second controlled switch to catalyze a swing of the quasi-resonant rail to the first voltage, commanding off all of the at least two controlled inverter switches not otherwise commanded on by the inverter control to release the quasi-resonant rail from the second voltage to thereby swing the quasi-resonant rail to the first voltage, commanding on the first controlled switch while the first diode is forward biased.
Claim 8
Dependent Claim
30 words
A DC link as claimed in claim 5 wherein the DC link control further commands off the second controlled switch while the quasi-resonant rail is at substantially the first voltage.
Claim 9
Dependent Claim
67 words
A DC link as claimed in claim 5 further comprising: a third controlled switch coupled across the second diode; a third diode coupled in anti-parallel across the second controlled switch; and the DC link control further executing power interrupt intervals by commanding on the third controlled switch prior to commanding off the first controlled switch to catalyze the swing of the quasi-resonant rail to the second voltage.
Claim 10
Dependent Claim
30 words
A DC link as claimed in claim 7 wherein the DC link control further commands off the third controlled switch while the quasi-resonant rail is at substantially the second voltage.
Claim 11
Dependent Claim
349 words
A DC link having a DC input and a DC output, the DC input coupled to a DC source and the DC output coupled to an inverter at an input thereof, said DC output having substantially a first voltage during power delivery intervals and substantially a second voltage during power interrupt intervals, the inverter having a plurality of controlled inverter switches commutated during power interrupt intervals by an inverter control, each inverter switch having an associated anti-parallel diode coupled thereacross, the DC link comprising: the DC input comprising a positive DC rail at the first voltage and a negative DC rail at the second voltage; the DC output comprising a quasi-resonant rail and the negative DC rail; a first controlled switch connected between the positive DC rail and the quasi-resonant rail; a first diode coupled in anti-parallel across the first controlled switch; first and second capacitors, the first capacitor coupled across the first controlled switch and the second capacitor coupled between the quasi-resonant rail and the negative DC rail; a second diode having an anode and a cathode, said anode coupled to the negative DC rail; an inductor coupled between the cathode of the third diode and the quasi-resonant rail; a second controlled switch coupled between the cathode of the second diode and the positive DC rail; controlled switch means connected between the quasi-resonant rail and the negative DC rail; rectifier means connected in anti-parallel across the controlled switch means; and a DC link control for executing power interrupt intervals intermediate power delivery intervals by sequentially commanding off the first controlled switch to release the quasi-resonant rail from the first voltage to thereby swing the quasi-resonant rail to the second voltage, commanding on the controlled switch means while the rectifier means is conductive, commanding on the second controlled switch to catalyze a swing of the quasi-resonant rail to the first voltage, commanding off the controlled switch means to release the quasi-resonant rail from the second voltage to thereby swing the quasi-resonant rail to the first voltage, commanding on the first controlled switch while the first diode is forward biased.
Claim 12
Dependent Claim
349 words
A DC link having a DC input and a DC output, the DC input coupled to a DC source and the DC output coupled to an inverter at an input thereof, said DC output having substantially a first voltage during power delivery intervals and substantially a second voltage during power interrupt intervals, the inverter having a plurality of controlled inverter switches commutated during power interrupt intervals by an inverter control, each inverter switch having an associated anti-parallel diode coupled thereacross, the DC link comprising: the DC input comprising a positive DC rail at the first voltage and a negative DC rail at the second voltage; the DC output comprising a quasi-resonant rail and the negative DC rail; a first controlled switch connected between the positive DC rail and the quasi-resonant rail; a first diode coupled in anti-parallel across the first controlled switch; first and second capacitors, the first capacitor coupled across the first controlled switch and the second capacitor coupled between the quasi-resonant rail and the negative DC rail; a second diode having an anode and a cathode, said anode coupled to the negative DC rail; an inductor coupled between the cathode of the third diode and the quasi-resonant rail; a second controlled switch coupled between the cathode of the second diode and the positive DC rail; controlled switch means connected between the quasi-resonant rail and the negative DC rail; rectifier means connected in anti-parallel across the controlled switch means; and a DC link control for executing power interrupt intervals intermediate power delivery intervals by sequentially commanding off the first controlled switch to release the quasi-resonant rail from the first voltage to thereby swing the quasi-resonant rail to the second voltage, commanding on the controlled switch means while the rectifier means is conductive, commanding on the second controlled switch to catalyze a swing of the quasi-resonant rail to the first voltage, commanding off the controlled switch means to release the quasi-resonant rail from the second voltage to thereby swing the quasi-resonant rail to the first voltage, commanding on the first controlled switch while the first diode is forward biased.
Claim 13
Dependent Claim
30 words
A DC link as claimed in claim 9 wherein the DC link control further commands off the second controlled switch while the quasi-resonant rail is at substantially the first voltage.
Claim 14
Dependent Claim
67 words
A DC link as claimed in claim 9 further comprising: a third controlled switch coupled across the second diode; a third diode coupled in anti-parallel across the second controlled switch; and the DC link control further executing power interrupt intervals by commanding on the third controlled switch prior to commanding off the first controlled switch to catalyze the swing of the quasi-resonant rail to the second voltage.
Claim 15
Dependent Claim
30 words
A DC link as claimed in claim 11 wherein the DC link control further commands off the third controlled switch while the quasi-resonant rail is at substantially the second voltage.
Claim 16
Dependent Claim
18 words
A DC link as claimed in claim 9 wherein the controlled switch means comprises a third controlled switch.
Claim 17
Dependent Claim
29 words
A DC link as claimed in claim 9 wherein the controlled switch means comprises at least two controlled inverter switches that are coupled in series across the inverter input.
Claim 18
Dependent Claim
16 words
A DC link as claimed in claim 9 wherein the rectifier means comprises a third diode.
Claim 19
Dependent Claim
18 words
A DC link as claimed in claim 11 wherein the controlled switch means comprises a fourth controlled switch.
Claim 20
Dependent Claim
29 words
A DC link as claimed in claim 11 wherein the controlled switch means comprises at least two controlled inverter switches that are coupled in series across the inverter input.
Claim 21
Dependent Claim
16 words
A DC link as claimed in claim 11 wherein the rectifier means comprises a fourth diode.
Claim 22
Independent Claim
287 words
A method of operating a DC link having a DC input and a DC output, the DC input coupled to a DC source and the DC output coupled to an inverter at an input thereof, the DC input comprising a positive DC rail at a first voltage and a negative DC rail-at a second voltage, the DC output comprising a quasi-resonant rail and the negative DC rail, the inverter comprising a plurality of controlled inverter switches, the DC link comprising a first controlled switch connected between the positive DC rail and the quasi-resonant rail, a first diode coupled in anti-parallel across the first controlled switch, first and second capacitors, the first capacitor coupled across the first controlled switch and the second capacitor coupled between the quasi-resonant rail and the negative DC rail, a second diode having an anode and a cathode, said anode coupled to the negative DC rail, an inductor coupled between the cathode of the third diode and the quasi-resonant rail, a second controlled switch coupled between the cathode of the second diode and the positive DC rail, controlled switch means connected between the quasi-resonant rail and the negative DC rail, and rectifier means connected in anti-parallel across the controlled switching means, the method comprising the steps of: commanding off the first controlled switch to swing the quasi-resonant rail to the second voltage; commanding on the controlled switching means while the rectifier means is conducting; commanding on the second controlled switch to catalyze a swing of the quasi-resonant rail to the first voltage; commanding off the controlled switching means to swing the quasi-resonant rail to the first voltage; and commanding on the first controlled switch while the quasi-resonant rail is at substantially the first voltage.
Claim 23
Independent Claim
287 words
A method of operating a DC link having a DC input and a DC output, the DC input coupled to a DC source and the DC output coupled to an inverter at an input thereof, the DC input comprising a positive DC rail at a first voltage and a negative DC rail-at a second voltage, the DC output comprising a quasi-resonant rail and the negative DC rail, the inverter comprising a plurality of controlled inverter switches, the DC link comprising a first controlled switch connected between the positive DC rail and the quasi-resonant rail, a first diode coupled in anti-parallel across the first controlled switch, first and second capacitors, the first capacitor coupled across the first controlled switch and the second capacitor coupled between the quasi-resonant rail and the negative DC rail, a second diode having an anode and a cathode, said anode coupled to the negative DC rail, an inductor coupled between the cathode of the third diode and the quasi-resonant rail, a second controlled switch coupled between the cathode of the second diode and the positive DC rail, controlled switch means connected between the quasi-resonant rail and the negative DC rail, and rectifier means connected in anti-parallel across the controlled switching means, the method comprising the steps of: commanding off the first controlled switch to swing the quasi-resonant rail to the second voltage; commanding on the controlled switching means while the rectifier means is conducting; commanding on the second controlled switch to catalyze a swing of the quasi-resonant rail to the first voltage; commanding off the controlled switching means to swing the quasi-resonant rail to the first voltage; and commanding on the first controlled switch while the quasi-resonant rail is at substantially the first voltage.
Claim 24
Dependent Claim
32 words
A method of operating a DC link as claimed in claim 19 further comprising the step: commanding off the second controlled switch while the quasi-resonant rail is at substantially the first voltage.
Claim 25
Dependent Claim
72 words
A method of operating a DC link as claimed in claim 19 wherein the DC link further comprises a third controlled switch coupled across the second diode, and a third diode coupled in anti-parallel across the second controlled switch, the method further comprising the steps of: commanding on the third controlled switch prior to commanding off the first controlled switch to catalyze the swing of the quasi-resonant rail to the second voltage.
Claim 26
Dependent Claim
32 words
A method of operating a DC link as claimed in claim 21 further comprising the step: commanding off the third controlled switch while the quasi-resonant rail is at substantially the second voltage.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-01-07 | 2000-07-08 | 2001-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-07 | 2004-07-08 | 2005-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-07 | 2008-07-08 | 2009-01-07 | $7700.00 | Window Closed / Lapsed |