US5321599A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control apparatus for suppressing a third harmonic neutral point voltage in a three level inverter
Assignee: Hitachi Ltd
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Filing: 1993-01-26
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Granted: 1994-06-14
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Expires: 2013-01-26
Abstract
Abstract The present invention relates to a control apparatus of a three-level inverter and intends to provide a control apparatus of simplified construction which can suppress a fluctuation in neutral point voltage effectively. Only a third harmonic component which is particularly large in the fluctuation in neutral point voltage is suppressed, a third harmonic component for suppression has a ratio of amplitude to that of a fundamental wave and a phase which are set to be constant regardless of the inverter frequency, and this third harmonic component is applied to a command of the fundamental wave.
Inventors
- 👤 Tokunosuke Tanamachi
- 👤 Kiyoshi Nakata
- 👤 Kiyoshi Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:10
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/483; H02M7/487; H02M7/4833; H02M7/53; H02M7/537; H02M7/539; H02M7/5395
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
108 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means has means for applying to said fundamental wave a third harmonic component thereof, and said third harmonic component is derived using values which do not change with the frequency of said fundamental wave.
Claim 2
Dependent Claim
108 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means has means for applying to said fundamental wave a third harmonic component thereof, and said third harmonic component is derived using values which do not change with the frequency of said fundamental wave.
Claim 3
Dependent Claim
119 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means has means for applying to said fundamental wave a third harmonic component thereof in a predetermined frequency region of said fundamental wave, and said third harmonic component has a ratio of amplitude to that of said fundamental wave and a phase which are constant.
Claim 4
Dependent Claim
119 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means has means for applying to said fundamental wave a third harmonic component thereof in a predetermined frequency region of said fundamental wave, and said third harmonic component has a ratio of amplitude to that of said fundamental wave and a phase which are constant.
Claim 5
Dependent Claim
119 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means has means for applying to said fundamental wave a third harmonic component thereof, and said third harmonic component has a constant ratio of amplitude to that of said fundamental wave and a phase relative to said fundamental wave which changes with the frequency thereof.
Claim 6
Dependent Claim
119 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means has means for applying to said fundamental wave a third harmonic component thereof, and said third harmonic component has a constant ratio of amplitude to that of said fundamental wave and a phase relative to said fundamental wave which changes with the frequency thereof.
Claim 7
Dependent Claim
119 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means has means for applying to said fundamental wave a third harmonic component thereof, and said third harmonic component has a ratio of amplitude to that of said fundamental wave which changes with the frequency thereof and a constant phase relative to said fundamental wave.
Claim 8
Dependent Claim
119 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means has means for applying to said fundamental wave a third harmonic component thereof, and said third harmonic component has a ratio of amplitude to that of said fundamental wave which changes with the frequency thereof and a constant phase relative to said fundamental wave.
Claim 9
Dependent Claim
148 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means is means for applying, in a first frequency region of said fundamental wave, a third harmonic component thereof having a ratio of amplitude to that of said fundamental wave and a phase which change with the frequency of said fundamental wave and applying, in a second frequency region of said fundamental wave, a third harmonic component thereof having a ratio of amplitude to that of said fundamental wave and a phase which are constant.
Claim 10
Dependent Claim
148 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means is means for applying, in a first frequency region of said fundamental wave, a third harmonic component thereof having a ratio of amplitude to that of said fundamental wave and a phase which change with the frequency of said fundamental wave and applying, in a second frequency region of said fundamental wave, a third harmonic component thereof having a ratio of amplitude to that of said fundamental wave and a phase which are constant.
Claim 11
Dependent Claim
143 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; and modulating means having a modulating region which expresses a half period of an output phase voltage of said fundamental wave by delivering positive and negative pulses to said power converter alternately; wherein said modulating wave generator means is means for applying, in a region other than said modulating region, a third harmonic component of said fundamental wave having a ratio of amplitude to that of said fundamental wave and a phase which are constant.
Claim 12
Dependent Claim
143 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; and modulating means having a modulating region which expresses a half period of an output phase voltage of said fundamental wave by delivering positive and negative pulses to said power converter alternately; wherein said modulating wave generator means is means for applying, in a region other than said modulating region, a third harmonic component of said fundamental wave having a ratio of amplitude to that of said fundamental wave and a phase which are constant.
Claim 13
Dependent Claim
139 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; and modulating means having a modulating region which expresses a half period of an output phase voltage of said fundamental wave by delivering positive and negative pulses to said power converter alternately; wherein said modulating wave generator means is means for applying, in a region inclusive of said modulating region, a third harmonic component having a ratio of amplitude to that of said fundamental wave and a phase which are constant.
Claim 14
Dependent Claim
139 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; and modulating means having a modulating region which expresses a half period of an output phase voltage of said fundamental wave by delivering positive and negative pulses to said power converter alternately; wherein said modulating wave generator means is means for applying, in a region inclusive of said modulating region, a third harmonic component having a ratio of amplitude to that of said fundamental wave and a phase which are constant.
Claim 15
Dependent Claim
133 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means is means for preparing, from said fundamental wave, a unit sine wave having a frequency which is three times the frequency of said fundamental wave and applying, to said fundamental wave, a third harmonic component having a ratio of amplitude to that of said fundamental wave and a phase which change with the frequency of said fundamental wave.
Claim 16
Dependent Claim
133 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means is means for preparing, from said fundamental wave, a unit sine wave having a frequency which is three times the frequency of said fundamental wave and applying, to said fundamental wave, a third harmonic component having a ratio of amplitude to that of said fundamental wave and a phase which change with the frequency of said fundamental wave.
Claim 17
Dependent Claim
130 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means is means for preparing, from said fundamental wave, a unit sine wave having a frequency which is three times the frequency of said fundamental wave and applying, to said fundamental wave, a third harmonic component having a ratio of amplitude to that of said fundamental wave and a phase which change with the power-factor angle.
Claim 18
Dependent Claim
130 words
A control apparatus of power converter comprising: a plurality of capacitors connected in series to divide DC voltage; a power converter fed with direct current from said capacitors and operative to convert the direct current into AC phase voltages each having three or more levels of potential; and modulating wave generator means for generating a command of a fundamental wave of alternating current delivered out of said power converter; wherein said modulating wave generator means is means for preparing, from said fundamental wave, a unit sine wave having a frequency which is three times the frequency of said fundamental wave and applying, to said fundamental wave, a third harmonic component having a ratio of amplitude to that of said fundamental wave and a phase which change with the power-factor angle.
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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) | 1997-06-13 | 1997-12-13 | 1998-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-13 | 2001-12-13 | 2002-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-13 | 2005-12-13 | 2006-06-14 | $7700.00 | Window Closed / Lapsed |