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US4472674A
Expired / Lapsed
US
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Method of static reactive power compensation
Assignee: Mitsubishi Electric Corp
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Filing: 1982-08-20
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Granted: 1984-09-18
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Expires: 2002-08-20
Abstract
Abstract A method of static reactive power compensation is disclosed wherein the system voltage is compensated by supplying advanced-phase or retarded phase reactive power in dependence upon the difference between the system voltage and a reference voltage. The difference is formed by a comparator which receives a variable reference voltage from a filter containing a time lag circuit and which receives the system voltage as an input. For transients, the output of the filter does not change and thus reactive power is applied. For smooth variations, the output of the filter follows that of the system voltage so that the output of the power compensation circuit is maintained at zero.
Inventors
- 👤 Masao Yano
- 👤 Hiroshi Suzuki
- 👤 Setsuro Mine
- 👤 Masatoshi Takeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:18
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/12; H02J3/16; Y; Y02; Y02E; Y02E40/00; Y02E40/30
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
94 words
A method of static reactive power compensation, comprising; supplying advanced-phase reactive power or lagged- phase reactive power in dependence on the difference between a system voltage and a reference voltage value; and varying said reference voltage value such that said value represents the system voltage within a desired interval of time, such that, in a steady state, said difference falls to zero to eliminate said reactive power, and such that, in a transient state, said difference is fed as an output to cause the supply of said reactive power for maintaining the system voltage.
Claim 2
Independent Claim
94 words
A method of static reactive power compensation, comprising; supplying advanced-phase reactive power or lagged- phase reactive power in dependence on the difference between a system voltage and a reference voltage value; and varying said reference voltage value such that said value represents the system voltage within a desired interval of time, such that, in a steady state, said difference falls to zero to eliminate said reactive power, and such that, in a transient state, said difference is fed as an output to cause the supply of said reactive power for maintaining the system voltage.
Claim 3
Dependent Claim
21 words
A method according to claim 1, wherein said reference voltage value is obtained by applying the system voltage through a filter.
Claim 4
Dependent Claim
18 words
A method according to claim 2, wherein said filter comprises a circuit having a first order time lag.
Claim 5
Dependent Claim
17 words
A method according to claim 3, wherein said circuit has a time constant of about 10 seconds.
Claim 6
Dependent Claim
49 words
A method according to claim 1, wherein said advanced-phase reactive power is supplied by a capacitor, and said lagged-phase reactive power is supplied by a reactor connected to a thyristor switch supplied with an ignition signal based on the deviation of said reference voltage value from the system voltage.
Claim 7
Dependent Claim
64 words
A method according to claim 1, wherein said reference voltage value is obtained by passing an output from a voltage detector circuit for detecting the system voltage through a filter, and a deviation of said reference voltage value from said system voltage is obtained by a comparator circuit with the output from said voltage detector circuit being supplied as an input to be compared.
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) | 1987-09-18 | 1988-03-19 | 1988-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-18 | 1992-03-19 | 1992-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-18 | 1996-03-19 | 1996-09-18 | $7700.00 | Window Closed / Lapsed |