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US4366533A
Expired / Lapsed
US
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PWM Inverter device
Assignee: Toyo Denki Seizo KK
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Filing: 1980-07-10
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Granted: 1982-12-28
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Expires: 2000-07-10
Abstract
Abstract An inverter device operating under pulse width modulation (PWM) principle in which chopping pulse is formed by crossing points of a triangle waveform and a function waveform in order that pulse width of the inverter input current decreases towards later half of pulse train in each period of pulse repetition series.
Inventors
- 👤 Masakazu Kohata
- 👤 Hideki Hayashi
- 👤 Ichiro Miyashita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:18
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; B; B60; B60L; B60L3/00; B60L9/00; B60L9/16; B60L9/18; B60L2200/00; B60L2200/26; H02P; H02P27/00; H02P27/04; H02P27/047
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
168 words
A PWM inverter device for energizing ac motor with variable voltage and variable frequency output obtained from a dc current source by pulse width adjustment, characterized in that the device comprises an oscillator for generating a series of output pulses synchronized with output frequency of the inverter and having frequency integral multiple of the output frequency, a function waveform generator for generating level signal having frequency of 2m times (m being an integer representing the number of phases of the inverter device) of the inverter output frequency in response to the output of said oscillator, a triangle waveform oscillator for generating triangle wave shaped carrier signal having a constant frequency at least 12 times with that of the inverter signal, a modulator for comparing and mixing said level signal with said carrier signal, wherein said level signal is generated in a functional form in order that the pulse width of the inverter output voltage decreases monotonically and forms repeated waveforms by a chopping instruction of the modulator output.
Claim 2
Dependent Claim
168 words
A PWM inverter device for energizing ac motor with variable voltage and variable frequency output obtained from a dc current source by pulse width adjustment, characterized in that the device comprises an oscillator for generating a series of output pulses synchronized with output frequency of the inverter and having frequency integral multiple of the output frequency, a function waveform generator for generating level signal having frequency of 2m times (m being an integer representing the number of phases of the inverter device) of the inverter output frequency in response to the output of said oscillator, a triangle waveform oscillator for generating triangle wave shaped carrier signal having a constant frequency at least 12 times with that of the inverter signal, a modulator for comparing and mixing said level signal with said carrier signal, wherein said level signal is generated in a functional form in order that the pulse width of the inverter output voltage decreases monotonically and forms repeated waveforms by a chopping instruction of the modulator output.
Claim 3
Dependent Claim
43 words
A PWM inverter device as claimed in claim 1, wherein said level signal generated by said function waveform generator and synchronized with said inverter output frequency and having 2m times frequency with that of the output frequency is generated as a sawtooth waveform.
Claim 4
Dependent Claim
33 words
A PWM inverter device as claimed in claim 1, wherein said function waveform generator comprises a memory element for memorizing said function waveform and signal is generated by reading out the memorized content.
Claim 5
Dependent Claim
43 words
A PWM inverter device as claimed in claim 1, wherein said level signal generated by said function waveform generator and synchronized with said inverter output frequency and having 2m times frequency with that of the output frequency is generated as an exponential waveform.
Claim 6
Dependent Claim
184 words
A PWM inverter device for energizing ac motor with variable voltage and variable frequency output obtained from a dc current source by pulse width adjustment, characterized in that the device comprises an oscillator for generating a series of output pulses synchronized with output frequency of the inverter and having frequency integral multiple of the output frequency, a function waveform generator for generating level signal having frequency of 2m times (m being an integer representing the number of phases of said inverter device) of the inverter output frequency in response to the output of said oscillator, a triangle waveform oscillator for generating triangle wave shaped carrier signal having a constant frequency at least 12 times with that of the inverter output signal, a modulator for comparing and mixing said level signal with said carrier signal, wherein during a period from starting time to a time when the inverter input frequency passes a certain predetermined frequency said level signal is generated in a functional waveform in order that the pulse width of the inverter output voltage decreases monotonically to form repeating waveforms by the chopping instruction.
Claim 7
Dependent Claim
184 words
A PWM inverter device for energizing ac motor with variable voltage and variable frequency output obtained from a dc current source by pulse width adjustment, characterized in that the device comprises an oscillator for generating a series of output pulses synchronized with output frequency of the inverter and having frequency integral multiple of the output frequency, a function waveform generator for generating level signal having frequency of 2m times (m being an integer representing the number of phases of said inverter device) of the inverter output frequency in response to the output of said oscillator, a triangle waveform oscillator for generating triangle wave shaped carrier signal having a constant frequency at least 12 times with that of the inverter output signal, a modulator for comparing and mixing said level signal with said carrier signal, wherein during a period from starting time to a time when the inverter input frequency passes a certain predetermined frequency said level signal is generated in a functional waveform in order that the pulse width of the inverter output voltage decreases monotonically to form repeating waveforms by the chopping instruction.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-27 | 1986-06-28 | 1986-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-27 | 1990-06-28 | 1990-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-27 | 1994-06-28 | 1994-12-28 | $7700.00 | Window Closed / Lapsed |