US4600981A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Margin angle responsive method and apparatus for controlling reactive power in a HVDC system
Assignee: Toshiba Mitsubishi Electric Industrial Systems Corp
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Filing: 1985-04-19
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Granted: 1986-07-15
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Expires: 2005-04-19
Abstract
Abstract A control method of the invention is formed with the steps of when a margin angle γ reaches a given minimum margin angle γmin during the operation of a rectifier and inverter, a shunt reactor is disconnected from, or a shunt capacitor is connected to, an AC line of the inverter, and when the margin angle γ exceeds the minimum margin angle γmin by a predetermined value, the shunt reactor is connected to, or the shunt capacitor is disconnected from, the AC line.
Inventors
- 👤 Takami Sakai
- 👤 Koji Imai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:26
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/36; Y; Y02; Y02E; Y02E60/00; Y02E60/60
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
92 words
A control method of phase modifying equipment which is adapted to a DC power transmission system, wherein reactive power of an AC line coupled to the DC power transmission system is controlled in accordance with a margin angle, said control method comprising the steps of: (a) when said margin angle reaches a given minimum margin angle, a phase-advancing reactance element being disconnected from said AC line; and (b) when said margin angle exceeds said given minimum margin angle by a predetermined value, said phase-advancing reactance element being connected to said AC line.
Claim 2
Dependent Claim
92 words
A control method of phase modifying equipment which is adapted to a DC power transmission system, wherein reactive power of an AC line coupled to the DC power transmission system is controlled in accordance with a margin angle, said control method comprising the steps of: (a) when said margin angle reaches a given minimum margin angle, a phase-advancing reactance element being disconnected from said AC line; and (b) when said margin angle exceeds said given minimum margin angle by a predetermined value, said phase-advancing reactance element being connected to said AC line.
Claim 3
Dependent Claim
92 words
A control method of phase modifying equipment which is adapted to a DC power transmission system, wherein reactive power of an AC line coupled to the DC power transmission system is controlled in accordance with a margin angle, said control method comprising the steps of: (a) when said margin angle reaches a given minimum margin angle, a phase-delaying reactance element being connected to said AC line; and (b) when said margin angle exceeds said given minimum margin angle by a predetermined value, said phase-delaying reactance element being disconnected from said AC line.
Claim 4
Dependent Claim
92 words
A control method of phase modifying equipment which is adapted to a DC power transmission system, wherein reactive power of an AC line coupled to the DC power transmission system is controlled in accordance with a margin angle, said control method comprising the steps of: (a) when said margin angle reaches a given minimum margin angle, a phase-delaying reactance element being connected to said AC line; and (b) when said margin angle exceeds said given minimum margin angle by a predetermined value, said phase-delaying reactance element being disconnected from said AC line.
Claim 5
Dependent Claim
93 words
A control apparatus of phase modifying equipment which is adapted to a DC power transmission system, wherein reactive power of an AC line coupled to the DC power transmission system is controlled in accordance with a margin angle, said control apparatus comprising: (a) first means, when said margin angle reaches a given minimum margin angle, for disconnecting a phase-advancing reactance element from said AC line; and (b) second means, when said margin angle exceeds said given minimum margin angle by a predetermined value, for connecting said phase-advancing reactance element to said AC line.
Claim 6
Dependent Claim
93 words
A control apparatus of phase modifying equipment which is adapted to a DC power transmission system, wherein reactive power of an AC line coupled to the DC power transmission system is controlled in accordance with a margin angle, said control apparatus comprising: (a) first means, when said margin angle reaches a given minimum margin angle, for disconnecting a phase-advancing reactance element from said AC line; and (b) second means, when said margin angle exceeds said given minimum margin angle by a predetermined value, for connecting said phase-advancing reactance element to said AC line.
Claim 7
Dependent Claim
93 words
A control apparatus of phase modifying equipment which is adapted to a DC power transmission system, wherein reactive power of an AC line coupled to the DC power transmission system is controlled in accordance with a margin angle, said control apparatus comprising: (a) primary means, when said margin angle reaches a given minimum margin angle, for connecting a phase-delaying reactance element to said AC line; and (b) secondary means, when said margin angle exceeds said given minimum margin angle by a predetermined value, for disconnecting said phase-delaying reactance element from said AC line.
Claim 8
Dependent Claim
93 words
A control apparatus of phase modifying equipment which is adapted to a DC power transmission system, wherein reactive power of an AC line coupled to the DC power transmission system is controlled in accordance with a margin angle, said control apparatus comprising: (a) primary means, when said margin angle reaches a given minimum margin angle, for connecting a phase-delaying reactance element to said AC line; and (b) secondary means, when said margin angle exceeds said given minimum margin angle by a predetermined value, for disconnecting said phase-delaying reactance element from said AC line.
Claim 9
Dependent Claim
96 words
A control apparatus according to claim 3, wherein said first means includes means for comparing said margin angle with said given minimum margin angle, and disconnecting said phase-advancing reactance element from said AC line when said margin angle corresponds to said given minimum margin angle; and wherein said second means includes means for comparing said margin angle with a specific value which is defined by the sum of said given minimum margin angle and said predetermined value, and connecting said phase-advancing reactance element to said AC line when said margin angle corresponds to said specific value.
Claim 10
Dependent Claim
96 words
A control apparatus according to claim 4, wherein said primary means includes means for comparing said margin angle with said given minimum margin angle, and connecting said phase-delaying reactance element to said AC line when said margin angle corresponds to said given minimum margin angle; and wherein said secondary means includes means for comparing said margin angle with a specific value which is defined by the sum of said given minimum margin angle and said predetermined value, and disconnecting said phase-delaying reactance element from said AC line when said margin angle corresponds to said specific value.
Claim 11
Dependent Claim
110 words
A control apparatus according to claim 3, further comprising: active power means for detecting active power handled by said DC power transmission system, and generating an active power signal; reactive power detector means for detecting reactive power handled by said DC power transmission system, and generating a reactive power signal; and comparator means coupled to said active power detector means and said reactive power detector means, for comparing a first value corresponding to said active power signal with a second value corresponding to said reactive power signal, and controlling a connecting state of said phase-advancing reactance element according to a condition that said first value corresponds to said second value.
Claim 12
Dependent Claim
33 words
A control apparatus according to claim 7, wherein said comparator means includes means for changing said second value by a predetermined amount in accordance with the connecting state of said phase-advancing reactance element.
Claim 13
Dependent Claim
111 words
A control apparatus according to claim 4, further comprising: active power detector means for detecting active power handled by said DC power transmission system, and generating an active power signal; reactive power detector means for detecting reactive power handled by said DC power transmission system, and generating a reactive power signal; and comparator means coupled to said active power detector means and said reactive power detector means, for comparing a first value corresponding to said active power signal with a second value corresponding to said reactive power signal, and controlling a disconnecting state of said phase-delaying reactance element according to a condition that said first value corresponds to said second value.
Claim 14
Dependent Claim
33 words
A control apparatus according to claim 9, wherein said comparator means includes means for changing said second value by a predetermined amount in accordance with the connecting state of said phase-delaying reactance element.
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) | 1989-07-14 | 1990-01-13 | 1990-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-14 | 1994-01-13 | 1994-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-14 | 1998-01-13 | 1998-07-15 | $7700.00 | Window Closed / Lapsed |