US4968338A
Expired / Lapsed
US
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Inverter controlled air conditioner with optimum determination for over current detection
Assignee: Toshiba Corp
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Filing: 1990-01-24
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Granted: 1990-11-06
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Expires: 2010-01-24
Abstract
Abstract A memory stores, in advance, at least a first V/F pattern corresponding to an air conditioning load and having reference voltage and frequency characteristics, and a second V/F pattern having voltage and frequency characteristics lower than those of the first V/F pattern in a starting region of a variable-capacity compressor for driving a refrigeration cycle. A detector detects an over current supplied to an inverter for driving the compressor. A controller stops the compressor through the inverter when the detector detects the over current, and restarts or holds the compressor through the inverter in accordance with the detection count of the over current. The compressor is restarted with the first V/F pattern from the memory when the detection count is smaller than a first predetermined count, and when the detection count reaches a second predetermined count larger than the first predetermined count. The compressor is restarted with reading out the second V/F pattern from the memory while the detection count is larger than the first predetermined count and is smaller than the second predetermined count. The compressor is held when the detection count reaches a third predetermined count obtained by adding "1" to the second predetermined count, thereby confirming an abnormality of and allowing determination whether the abnormality occurs in the inverter or in the compressor.
Inventors
- 👤 Akiyoshi Sugiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:07
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/08; H02H7/0833; F; F04; F04B; F04B49/00; F04B49/06; F04B49/065; F04B2203/00; F04B2203/02; F04B2203/0201; F04B2207/00; F04B2207/01; F25; F25B; F25B2500/00; F25B2500/26; F25B2600/00; F25B2600/02; F25B2600/021; Y; Y02; Y02B; Y02B30/00; Y02B30/70
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
290 words
An air conditioner comprising: a variable-capacity compressor for varying a capacity to circulate a refrigerant in a refrigeration cycle; an inverter circuit including rectifying means for rectifying an AC input, and inverter means for switching an output current from said rectifying means to supply a V/F pattern having predetermined voltage and frequency characteristics to said variable-capacity compressor; memory means for storing, in advance, at least a first V/F pattern corresponding to an air conditioning load and having reference voltage and frequency characteristics, and a second V/F pattern having voltage and frequency characteristics lower than those of said first V/F pattern in a starting region of said variable-capacity compressor; over current detecting means for detecting an over current supplied to said inverter circuit; control means for stopping said variable-capacity compressor through said inverter circuit when said over current detecting means detects the over current, and restarting or holding said variable-capacity compressor through said inverter circuit in accordance with the detection count of the over current, said variable-capacity compressor being restarted by reading out said first V/F pattern from said memory means when the detection count is smaller than a first predetermined count, and when the detection count reaches a second predetermined count larger than the first predetermined count, said variable-capacity compressor being restarted by reading out said second V/F pattern from said memory means while the detection count is larger than the first predetermined count and is smaller than the second predetermined count, said variable-capacity compressor being held when the detection count reaches a third predetermined detection count obtained by adding "1" to the second predetermined count, thereby confirming an abnormality of said air conditioner and allowing determination whether the abnormality occurs in said inverter circuit or in said variable-capacity compressor.
Claim 2
Dependent Claim
290 words
An air conditioner comprising: a variable-capacity compressor for varying a capacity to circulate a refrigerant in a refrigeration cycle; an inverter circuit including rectifying means for rectifying an AC input, and inverter means for switching an output current from said rectifying means to supply a V/F pattern having predetermined voltage and frequency characteristics to said variable-capacity compressor; memory means for storing, in advance, at least a first V/F pattern corresponding to an air conditioning load and having reference voltage and frequency characteristics, and a second V/F pattern having voltage and frequency characteristics lower than those of said first V/F pattern in a starting region of said variable-capacity compressor; over current detecting means for detecting an over current supplied to said inverter circuit; control means for stopping said variable-capacity compressor through said inverter circuit when said over current detecting means detects the over current, and restarting or holding said variable-capacity compressor through said inverter circuit in accordance with the detection count of the over current, said variable-capacity compressor being restarted by reading out said first V/F pattern from said memory means when the detection count is smaller than a first predetermined count, and when the detection count reaches a second predetermined count larger than the first predetermined count, said variable-capacity compressor being restarted by reading out said second V/F pattern from said memory means while the detection count is larger than the first predetermined count and is smaller than the second predetermined count, said variable-capacity compressor being held when the detection count reaches a third predetermined detection count obtained by adding "1" to the second predetermined count, thereby confirming an abnormality of said air conditioner and allowing determination whether the abnormality occurs in said inverter circuit or in said variable-capacity compressor.
Claim 3
Dependent Claim
30 words
An air conditioner according to claim 1, wherein said inverter means includes a transistor module for switching an output current from said rectifying means to output a pseudo AC waveform.
Claim 4
Dependent Claim
26 words
An air conditioner according to claim 1, wherein said over current detecting means includes a current transformer for detecting an output current from said rectifying means.
Claim 5
Dependent Claim
47 words
An air conditioner according to claim 1, wherein said memory means includes a ROM for storing data of a starting frequency, a V/F inflection point, a gradient constant below the inflection point, and a gradient constant above the inflection point, as a predetermined number of patterns, respectively.
Claim 6
Dependent Claim
17 words
An air conditioner according to claim 4, wherein the data of the starting frequency includes four patterns.
Claim 7
Dependent Claim
18 words
An air conditioner according to claim 4, wherein the data of the V/F inflection point includes sixteen patterns.
Claim 8
Dependent Claim
18 words
An air conditioner according to claim 4, wherein the gradient constant below the inflection point includes eight patterns.
Claim 9
Dependent Claim
18 words
An air conditioner according to claim 4, wherein the gradient constant above the inflection point includes eight patterns.
Claim 10
Dependent Claim
18 words
An air conditioner according to claim 4, wherein said control means allows four tries of the restarting operation.
Claim 11
Dependent Claim
30 words
An air conditioner according to claim 9, wherein the first to third restarting operations are performed two minutes and twenty seconds after a holding state of said compressor is set.
Claim 12
Dependent Claim
27 words
An air conditioner according to claim 9, wherein the first, second, and fourth restarting operations are performed by reading out said first pattern from said memory means.
Claim 13
Dependent Claim
24 words
An air conditioner according to claim 9, wherein the third restarting operation is performed by reading out said second pattern from said memory means.
Claim 14
Dependent Claim
72 words
An air conditioner according to claim 9, wherein when said over current detecting means detects an over current after the fourth restarting operation is performed, said control means determines that an abnormality occurs in said inverter circuit if the over current is detected before a predetermined time elapsed, and said control means determines that an abnormality occurs in said variable-capacity compressor if the over current is detected after the predetermined time elapsed.
Claim 15
Dependent Claim
28 words
An air conditioner according to claim 1, wherein said air conditioner further comprises display means for displaying a determination result of the abnormality determined by said control means.
Claim 16
Dependent Claim
48 words
An air conditioner according to claim 14, wherein said control means outputs a code signal, the code signal which is output when an abnormality of said inverter circuit is determined being different from the code signal which is output when an abnormality of said variable-capacity compressor is determined.
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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) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |