US5081591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optimizing reactive power distribution in an industrial power network
Assignee: Emerson Process Management Power and Water Solutions Inc
•
Filing: 1990-02-28
•
Granted: 1992-01-14
•
Expires: 2010-02-28
Abstract
Abstract A system and method for optimizing the costs associated with the generation and flow of reactive power in an industrial plant connected to receive power from an electrical power utility and including a plurality of electromechanical rotating machines and electrical loads connected in a network, each machine having a reactive power characteristic and an excitation element which is controllable for adjusting the reactive power generated or absorbed by the machine. Control is achieved by: creating a model of the network for providing an indication of the reactive power to be supplied by the utility in dependence on representations of selected network electrical parameters including the reactive power generated or absorbed by each machine; providing an indication of the cost associate with reactive power flow as represented by the model; providing to the model sets of representations of altered values of reactive power generated or absorbed by each machine and causing the model to produce an indication for each set of representations; determining the lowest cost indication provided after the model has provided indications relating to a plurality of different sets of representations provided to the model; and providing an indication of the control to be effected on the excitation element of each machine to produce or absorb the amount of reactive power indicated by the model with respect to the set of representations for which the lowest cost indication is produced in the determining step.
Inventors
- 👤 James E. Hanway
- 👤 Richard E. Putman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:24
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/18; H02J3/1821; H02J3/1871; G; G06; G06Q; G06Q30/00; G06Q30/02; G06Q30/0283; Y; Y04; Y04S; Y04S50/00; Y04S50/14
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
295 words
A system for optimizing the costs associated with the generation and flow of reactive power in an industrial plant connected to receive power from an electrical power utility and including a plurality of electromechanical rotating machines and electrical loads connected in a network, each machine having a reactive power characteristic and an excitation element which is controllable for adjusting the reactive power generated or absorbed by the machine, said system comprising: means defining a model of the network for providing an indication of the quantity of reactive power to be supplied by the utility in dependence on representations of selected network electrical parameters including the reactive power generated or absorbed by each machine; cost determining means connected to said means defining a model for receiving the indication provided by the model and providing an indication of the cost associated with reactive power flow as represented by the model; network model parameter perturbing means connected to said model means for providing to said model means sets of representations of altered values of the quantity of reactive power generated or absorbed by each machine; comparison means connected to said cost determining means for determining the lowest cost indication provided by said cost determining means after said model means have provided reactive power quantity indications relating to a plurality of sets of representations provided by said perturbing means; and machine control means connected to said comparison means and to the excitation element of at least one of the rotating machines for controlling the operation of the excitation element of the at least one machine to produce or absorb the amount of reactive power indicated by said model means with respect to the set of representations for which the lowest cost indication is produced by said cost determining means.
Claim 2
Independent Claim
295 words
A system for optimizing the costs associated with the generation and flow of reactive power in an industrial plant connected to receive power from an electrical power utility and including a plurality of electromechanical rotating machines and electrical loads connected in a network, each machine having a reactive power characteristic and an excitation element which is controllable for adjusting the reactive power generated or absorbed by the machine, said system comprising: means defining a model of the network for providing an indication of the quantity of reactive power to be supplied by the utility in dependence on representations of selected network electrical parameters including the reactive power generated or absorbed by each machine; cost determining means connected to said means defining a model for receiving the indication provided by the model and providing an indication of the cost associated with reactive power flow as represented by the model; network model parameter perturbing means connected to said model means for providing to said model means sets of representations of altered values of the quantity of reactive power generated or absorbed by each machine; comparison means connected to said cost determining means for determining the lowest cost indication provided by said cost determining means after said model means have provided reactive power quantity indications relating to a plurality of sets of representations provided by said perturbing means; and machine control means connected to said comparison means and to the excitation element of at least one of the rotating machines for controlling the operation of the excitation element of the at least one machine to produce or absorb the amount of reactive power indicated by said model means with respect to the set of representations for which the lowest cost indication is produced by said cost determining means.
Claim 3
Dependent Claim
88 words
A system as defined in claim 1 wherein the plant includes a plurality of buses each connected to at least one of: the power utility; a rotating machine; and an electrical load, and the model has the form of a Newton-Raphson matrix which receives representations of selected values of the real and reactive power flow quantities from the utility, from each machine and to each load, and the model is operative for producing calculated values for the reactive power quantity to be produced or absorbed by each machine.
Claim 4
Dependent Claim
40 words
A system as defined in claim 2 wherein the plant further has at least one transformer having an adjustable transformation ratio, and said means defining a model is further operative for producing a calculated value for the transformer transformation ratio.
Claim 5
Dependent Claim
20 words
A system as defined in claim 3 wherein said perturbing means are operative to perform an evolutionary operation optimizing procedure.
Claim 6
Dependent Claim
32 words
A system as defined in claim 4 wherein said perturbing means are operative to additionally provide, in each set of representations, a selected altered value of the transformation ratio of the transformer.
Claim 7
Dependent Claim
64 words
A system as defined in claim 5 wherein the representations for which altered values are provided by said perturbing means have the form of an ordered array of representations, each representation is altered by an amount which decreases progressively from one representation in the array to the next, and said perturbing means are operative to periodically change the order of representations in the array.
Claim 8
Dependent Claim
29 words
A system as defined in claim 6 wherein said perturbing means are operative to change the order of representations in the array in at least an approximately random manner.
Claim 9
Dependent Claim
32 words
A system as defined in claim 1 wherein said machine control means are connected to said excitation element of each machine for controlling the operation of the excitation element of each machine.
Claim 10
Independent Claim
235 words
A method for optimizing the costs associated with the generation and flow of reactive power in an industrial plant connected to receive power from an electrical power utility and including a plurality of electromechanical rotating machines and electrical loads connected in a network, each machine having a reactive power characteristic and an excitation element which is controllable for adjusting the reactive power generated or absorbed by the machine, said method comprising: creating a model of the network for providing an indication of the quantity of reactive power to be supplied by the utility in dependence on representations of selected network electrical parameters including the reactive power generated or absorbed by each machine; providing an indication of the cost associated with reactive power flow as represented by the model; providing to the model sets of representations of altered values of the quantity of reactive power generated or absorbed by each machine and causing the model to produce an indication for each set of representations; determining the lowest cost indication provided after the model has provided indications relating to a plurality of different sets of representations provided to the model; and controlling the excitation element of at least one of the machines to produce or absorb the amount of reactive power indicated by the model with respect to the set of representations for which the lowest cost reactive power quantity indication is produced in said determining step.
Claim 11
Independent Claim
235 words
A method for optimizing the costs associated with the generation and flow of reactive power in an industrial plant connected to receive power from an electrical power utility and including a plurality of electromechanical rotating machines and electrical loads connected in a network, each machine having a reactive power characteristic and an excitation element which is controllable for adjusting the reactive power generated or absorbed by the machine, said method comprising: creating a model of the network for providing an indication of the quantity of reactive power to be supplied by the utility in dependence on representations of selected network electrical parameters including the reactive power generated or absorbed by each machine; providing an indication of the cost associated with reactive power flow as represented by the model; providing to the model sets of representations of altered values of the quantity of reactive power generated or absorbed by each machine and causing the model to produce an indication for each set of representations; determining the lowest cost indication provided after the model has provided indications relating to a plurality of different sets of representations provided to the model; and controlling the excitation element of at least one of the machines to produce or absorb the amount of reactive power indicated by the model with respect to the set of representations for which the lowest cost reactive power quantity indication is produced in said determining step.
Claim 12
Dependent Claim
23 words
A method as defined in claim 9 wherein said step of controlling is carried out to control the excitation element of each machine.
References Cited (Backward Citations)
US4236108A
Cited
US4356440A
Cited
US4417194A
Cited
US4607325A
Cited
US4672298A
Cited
US4628462A
Cited
US4663703A
Cited
US4745758A
Cited
US4935886A
Cited
US4805114A
Cited
US4916377A
Cited
US4912624A
Cited
US4876497A
Cited
US4999565A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-13 | 1995-07-15 | 1996-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-13 | 1999-07-15 | 2000-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-13 | 2003-07-15 | 2004-01-14 | $7700.00 | Window Closed / Lapsed |