US5642000A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for preventing power collapse in electric power systems
Assignee: Cornell Research Foundation Inc
•
Filing: 1993-05-03
•
Granted: 1997-06-24
•
Expires: 2013-05-03
Abstract
Abstract The present invention features a method for determining a performance index for each power-generating system, directly correlated to load demands. This performance index can be easily interpreted by power engineers and operators, so that weak areas and potential voltage collapse conditions can be predicted and corrected. When the underlying cause of collapse is due to load variations, the performance index of the current invention has the ability to assess the amount of load increase that the system can tolerate prior to such collapse. When the underlying collapse mechanism is due to a contingency, the performance index of this invention can measure its severity. The performance index of this invention can also assess whether the system can sustain a contingency without collapse.
Inventors
- 👤 Rene Jean-Jumeau
- 👤 Hsiao-Dong Chiang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:09
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/18; H02J3/1821; H02J3/1871
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
140 words
A method of preventing voltage collapse in a power-generating system having a grid comprising a plurality of load buses, comprising the steps of: a) measuring load flow in the power-generating system having a grid comprising a plurality of load buses; b) calculating a voltage collapse index (VCI) directly correlated to load demands of the power-generating system of step (a); c) utilizing the voltage collapse index to identify weak areas in the power-generating system; d) selecting a cluster of said load buses of said grid identified as weak areas for load variation; e) determining actual safety margins that exist for these weak areas before collapse will occur; and f) shedding power in those selected load buses of said grid that are identified as weak areas, in order to prevent voltage collapse in the power-generating system in accordance with said safety margins.
Claim 2
Independent Claim
140 words
A method of preventing voltage collapse in a power-generating system having a grid comprising a plurality of load buses, comprising the steps of: a) measuring load flow in the power-generating system having a grid comprising a plurality of load buses; b) calculating a voltage collapse index (VCI) directly correlated to load demands of the power-generating system of step (a); c) utilizing the voltage collapse index to identify weak areas in the power-generating system; d) selecting a cluster of said load buses of said grid identified as weak areas for load variation; e) determining actual safety margins that exist for these weak areas before collapse will occur; and f) shedding power in those selected load buses of said grid that are identified as weak areas, in order to prevent voltage collapse in the power-generating system in accordance with said safety margins.
Claim 3
Dependent Claim
38 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 1, wherein as part of the calculation of VCI, said method additionally obtains an exact point of voltage collapse (PVC) for the power-generating system.
Claim 4
Dependent Claim
44 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 1, wherein as part of the calculation of VCI and safety margins, said method varies reactive power on at least one of a plurality of buses for the power-generating system.
Claim 5
Dependent Claim
34 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 3, wherein reactive power is simultaneously varied on at least two of the plurality of buses for the power-generating system.
Claim 6
Dependent Claim
28 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 1, further comprising the step of: f) determining load-sustaining capacities of the weak areas.
Claim 7
Independent Claim
140 words
A method of preventing voltage collapse in a power-generating system having a grid comprising a plurality of load buses, comprising the steps of: a) measuring the load demands in the power-generating system having a grid comprising a plurality of load buses; b) calculating a voltage collapse index (VCI) directly correlated to load demands of the power-generating system of step (a); c) utilizing the voltage collapse index to identify weak areas in the power-generating system; d) selecting a cluster of said load buses of said grid identified as weak areas for load variation; e) determining actual safety margins that exist for these weak areas before collapse will occur; and f) adding power-generating capacity to those selected load buses of said grid that are identified as weak areas of said power-generating system, in order to prevent voltage collapse during heavy load conditions.
Claim 8
Independent Claim
140 words
A method of preventing voltage collapse in a power-generating system having a grid comprising a plurality of load buses, comprising the steps of: a) measuring the load demands in the power-generating system having a grid comprising a plurality of load buses; b) calculating a voltage collapse index (VCI) directly correlated to load demands of the power-generating system of step (a); c) utilizing the voltage collapse index to identify weak areas in the power-generating system; d) selecting a cluster of said load buses of said grid identified as weak areas for load variation; e) determining actual safety margins that exist for these weak areas before collapse will occur; and f) adding power-generating capacity to those selected load buses of said grid that are identified as weak areas of said power-generating system, in order to prevent voltage collapse during heavy load conditions.
Claim 9
Dependent Claim
38 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 6, wherein as part of the calculation of VCI, said method additionally obtains an exact point of voltage collapse (PVC) for the power-generating system.
Claim 10
Dependent Claim
44 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 6, wherein as part of the calculation of VCI and safety margins, said method varies reactive power on at least one of a plurality of buses for the power-generating system.
Claim 11
Dependent Claim
34 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 8, wherein reactive power is simultaneously varied on at least two of said plurality of buses for the power-generating system.
Claim 12
Dependent Claim
28 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 6, further comprising the step of: f) determining load-sustaining capacities of the weak areas.
Claim 13
Independent Claim
76 words
A method of preventing voltage collapse in a power-generating system, comprising the steps of: a) measuring the load demands in the power-generating system; b) calculating a voltage collapse index (VCI) directly correlated to load demands of the power-generating system of step a) wherein reactive power is simultaneously varied on at least two of a plurality of buses for the power-generating system; and c) utilizing the voltage collapse index to prevent power failure in said power-generating system.
Claim 14
Independent Claim
76 words
A method of preventing voltage collapse in a power-generating system, comprising the steps of: a) measuring the load demands in the power-generating system; b) calculating a voltage collapse index (VCI) directly correlated to load demands of the power-generating system of step a) wherein reactive power is simultaneously varied on at least two of a plurality of buses for the power-generating system; and c) utilizing the voltage collapse index to prevent power failure in said power-generating system.
Claim 15
Dependent Claim
51 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 11, wherein an underlying collapse mechanism of said power-generating system is determined to be due to a contingency, said method further comprising the step of: d) utilizing the voltage collapse index to measure severity of said contingency.
Claim 16
Dependent Claim
56 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 11, wherein an underlying collapse mechanism of said power-generating system is determined to be due to a contingency, said method further comprising the step of: d) utilizing the voltage collapse index to assess whether the system can sustain a contingency without collapse.
Claim 17
Dependent Claim
62 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 11, wherein an underlying collapse mechanism of said power-generating system is determined to be due to load variations, said method further comprising the step of: d) utilizing the voltage collapse index to assess the amount of load increase that the power-generating system can tolerate prior to such collapse.
Claim 18
Independent Claim
75 words
A method of preventing voltage collapse in a power-generating system, comprising the steps of: a) measuring the load demands in the power-generating system; b) calculating a voltage collapse index (VCI) directly correlated to load demands of the power-generating system of step (a) wherein reactive power is varied on at least one of a plurality of buses for the power-generating system; and c) utilizing the voltage collapse index to prevent power failure in said power-generating system.
Claim 19
Independent Claim
75 words
A method of preventing voltage collapse in a power-generating system, comprising the steps of: a) measuring the load demands in the power-generating system; b) calculating a voltage collapse index (VCI) directly correlated to load demands of the power-generating system of step (a) wherein reactive power is varied on at least one of a plurality of buses for the power-generating system; and c) utilizing the voltage collapse index to prevent power failure in said power-generating system.
Claim 20
Dependent Claim
51 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 15, wherein an underlying collapse mechanism of said power-generating system is determined to be due to a contingency, said method further comprising the step of: d) utilizing the voltage collapse index to measure severity of said contingency.
Claim 21
Dependent Claim
56 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 15, wherein an underlying collapse mechanism of said power-generating system is determined to be due to a contingency, said method further comprising the step of: d) utilizing the voltage collapse index to assess whether the system can sustain a contingency without collapse.
Claim 22
Dependent Claim
62 words
The method of preventing voltage collapse in a power-generating system in accordance with claim 15, wherein an underlying collapse mechanism of said power-generating system is determined to be due to load variations, said method further comprising the step of: d) utilizing the voltage collapse index to assess the amount of load increase that the power-generating system can tolerate prior to such collapse.
References Cited (Backward Citations)
US4181950A
Cited
US4549274A
Cited
US4612619A
Cited
US4694192A
Cited
US4868410A
Cited
US4794272A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-06-23 | 2000-12-23 | 2001-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-06-23 | 2004-12-23 | 2005-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-06-23 | 2008-12-23 | 2009-06-24 | $7700.00 | Window Closed / Lapsed |