Not Applicable
The present disclosure relates generally to electric power and, more particularly, to systems and methods of analyzing and determining optimal scheduling of various generation resources.
Prior to the development of the present disclosure, unit commitment of generation resources and real-time dispatch of generation were analyzed using spreadsheet-based calculations, heuristic methods, and approximation algorithms such as Lagrangian Relaxation, to calculate approximately efficient uses and dispatch of generation resources and products. Such earlier methods require such a high level of approximation and/or imprecise calculation methods that solutions achieved are not accurate enough and do not produce optimal results such as the minimization of operating costs. Some of the manual methods used to solve the problem equations were not streamlined with input-entering methods. As a result, gathering all required inputs for some calculations became too burdensome, as many inputs came from different sources, required preliminary calculations to obtain, or changed frequently. Further, although hypothetical (study mode) calculations were possible, but such manual collection and entering of inputs made performing these hypothetical calculations impractical. Hypothetical calculations are useful, inter alia, in making decisions relating to whether to purchase another generation provider's more economical energy, and thus their ease of use helps to develop informed business decisions.
All energy, whether generated or purchased from other generation owners, must be transmitted over available transmission channels in a way that falls within physical limitations and meets industry and regulatory standards. Prior to the development of the present disclosure, generation owners needed to compare generation and energy-purchase plans with multiple sources of available and committed transmission data. This added to complexity and prevented efficient selection of the most cost-effective generation/purchase plan.
Analysis of energy trading was performed by persons of ordinary skill in the art by comparing generation requirements to serve load with current generation forecasts, maximum available generation, and energy-purchase deals from other generation owners. The costs of increasing current generation and purchasing energy from numerous other generation owners were able to be compared, but no pre-existing system allows an integrated, customizable utilization of all generation resources, at a minimal cost, while satisfying scheduling and delivery constraints.
For example, if a generation owner discovered increased energy demand to be served or developed ambitions to generate the energy for the load another generation owner is currently serving, said generation owner could increase the output of the generation fleet. However, the generation owner was faced with an inaccurate and cumbersome method of developing a plan for said increased output. Such a plan requires knowledge not only of all the generation units with capability to increase output, but of the cost of increasing the output for each generating unit by specific amounts. The required parameters of these hypothetical specific increases, for all generation units, must then be compared to determine the most cost-effective method of increasing fleet generation to meet the new demand or requirements of said other load generation unit.
The present disclosure relates to systems and methods for considering a various multitude of input factors to calculate optimal solutions, here defined as the minimization of costs or the converse maximization of profit, over time in the generation and procurement of energy. These calculations may be subject to certain global system or individualized resource limitations. Functionalities in furtherance of calculating optimization include, but are not limited to, creating operating plans for generation utilization or evaluating the impacts of potential energy trade opportunities within a defined zone of generation assets.
The current embodiments address the problems inherent in the prior art with a new system for determining optimal-cost solutions. The system automatically collects, transfers, and stores all inputs and outputs needed for determining a solution, and automatically includes some inputs that were not previously considered either because of difficulty in procurement or because they are time consuming to obtain. The system provides functionality for solutions to be obtained automatically at set intervals, or upon the occurrence of certain events. The system ensures specificity to a generation owner's situation by allowing customization of inputs and algorithms to take non-cost factors into account when determining solutions. Finally, the system provides functionality for the customizable presentation of analysis comparing generation and trading, allowing for more complete results.
Turning now to the drawings in greater detail, it will be seen that
If step 108 determines that the Inputs 104 are valid, the module will formulate the objective function (step 112) by feeding the applicable Inputs 104 into an equation representing the potential output plans of all generation units. The set of all possible variations of this objective function thus represents all possible energy-generation plans based on Inputs 104. Optimal cost may be found by minimizing the objective function to minimize cost (primal sub-problem), or maximizing function to maximize profit (dual sub-problem), depending on the terms of the objective function. This objective function is then sent to the solver with equations representing constraints to be applied to the objective function (step 114). These constraints, expressed as equations, are limitations to be applied to the variables in the objective function and set boundaries on what forms of the objective function and its variables (and thus, what solutions) are acceptable. Examples of constraints are shown in
In some embodiments the module will have the ability to translate all equations from complex form to applicable program language. In preferred embodiments the constraint equations are permanently converted to the applicable program language and stored as such in the code of the module. The particular language into which the equations are converted is not important to this embodiment, but the program language chosen must be understood by all programs and modules required to implement the equations. The solver may be functionality internal to the module or a separate program to which the equation data must be sent. In some embodiments the solver may be a third-party API.
After equations are sent to the solver (step 114) the module queries the solver for the solution (step 116). In some embodiments the module may repeatedly query the solver, repeating step 116, if necessitated by the solver failing to calculate the solution before the first query. The solver in this embodiment sends information that the problem is not solvable if the objective function cannot be minimized/maximized, as applicable, to optimize costs while bound by all constraints. If the module receives such information an equation error is reported to user (step 118). In other non-user-initiated embodiments the equation error could be reported to another part of a larger program or system in which the module is integrated. Said larger program or system may contain a set of rules that determines automatic responses to said equation error or may enter it into a log for further reference.
If the module receives information that the problem is solvable, the solver retrieves solution data (step 120). In this embodiment the solution data is a cost-optimal generation plan, and is reported to a user (step 122) concurrently with being written into Database 102 (step 124). In one embodiment the solution data may be a single cost-optimal generation plan while other, equally cost-optimal plans are either not retrieved by the module or deleted upon retrieval. Other embodiments may involve the module reporting some or all cost-optimal generation plans, at which point the user may incorporate non-cost-based considerations into the selection of a generation plan. In further embodiments, generation plans higher in cost by or below a certain (or given) percentage threshold may be reported with the optimal-cost plan. Such percentage threshold may be coded into the program or set by a user through an interface. Multiple plans may be retrieved and reported to the user as a multiple-plan list or each plan may be reported separately, allowing the user to choose to retrieve further plans only if desired.
There are several possible embodiments by which a user could incorporate non-cost-based considerations when selecting from a multitude of optimal-cost generation plans. A user may, for example, have non-cost based reasons to prefer one generation unit over a single or plurality of other generation unit(s). That user could ensure that said preferred generation unit would be selected in any solution in which said preferred generation unit was one of several other possible generation units of an optimal-cost generation plan by lowering a cost-based input (such as fuel cost) of the preferred generation unit in Database 102. In preferred embodiments said cost-based-input would be lowered by an amount large enough such that the solver preferred said generation unit over other generation units in forming an optimal-cost generation plan, but by an amount small enough such that the overall cost of the generation plan would not be materially affected. The solver would then automatically select the preferred generating unit only in situations in a generation plan using the preferred generating unit had the same or lower cost as using other generation units instead of the preferred generation unit. This functionality requires the user of the embodiment module to have read/write access to the input information in Database 102.
One further embodiment by which a user could incorporate non-cost-based considerations when selecting from a multitude of optimal-cost generation plans involves the module sorting the solution data after having been retrieved in step 120. Said embodiment would include a user interface wherein the user is able to input rules the module is to follow in sorting solution data between step 120 and steps 122 and/or 124. For example, rules may allow a user to prefer one generation unit over all others if the total-generation-plan cost utilizing said preferred generation unit were within a certain percentage of the optimal-cost generation plan not utilizing said preferred generation unit. In this way the system may force the generation unit to deliver its energy in a non-optimal generation plan. The design of such a rule-creation interface would be determined by the language in which the module was programmed and the list of Inputs 104 in Database 102, but could resemble rule-creation interfaces common in the art.
The embodiment in
Embodiments not initiated by a user could offer unique advantages. For example, one embodiment could involve a module similar to that disclosed in
Inputs 202-240 may describe long-term and instantaneous properties of generating units, forecasted and instantaneous properties of the energy market and transmission system, and regulatory requirements of any of the above. Inputs 202-240 may take multiple forms even in the embodiment presented. For example, when reading Generation Unit Minimum Output 202 from Database 200, the module may require a minimum generation amount that is based on any or all of economic considerations, safety factors, or feasibility factors for any individual generating unit.
The order in which constraints are applied to the data is unlikely to, in most embodiments, have any effect on the solution. However, different solution programs (solvers) may calculate solutions slightly faster with the constraints applied in a certain order than in a different order. In some uses of the module, such as developing an optimal-cost generation plan with a very large fleet of generation units, this difference in calculation speed may significantly affect how feasibly the module can be used to inform generation decisions in real time. Therefore, it is desirable that the module contain functionality to alter the order in which the constraints are applied. This ability may either be implemented through a user interface or may require the order to be changed in to code of the module.
Presenting the user with hypothetical solutions using this slack functionality, in the case of calculating an optimum-cost generation plan, would provide the user with an easy method of analyzing the outcome, from a business or safety perspective, of altering the generation-plan parameters. For example, if the problem were determined to be unsolvable because the total energy generated by a generation plan was below the energy demanded for a particular time, the user could increase the total-energy-generated input parameter in step 406B, for example, by establishing purchase agreements with other energy providers, thereby causing the total-energy-generated input parameter to equal the energy-demanded parameter and view the resulting optimum-cost generation plan. In a further example, the problem may be determined to be unsolvable because all generation plans would require generation output at at least one generation unit to be above a long-term safety maximum, and the “Generation output falls between prescribed values” 306 constraint would thus be violated. The user could employ step 406A to relax this constraint, either by increasing the maximum output allowed by the constraint to the point at which at least one generation plan existed with all generation units' outputs falling within the relaxed constraint, or by instructing the module to not consider whether the generation units' outputs fell within prescribed values. Users can then make an informed decision regarding whether to purchase the energy needed to increase the total energy the appropriate amount based in part upon the desirability of the resulting solution as calculated.
The embodiment in
In a further embodiment allowing the pursuit of hypothetical solutions, the user may be given the functionality, independent of the equations being reported to the user as unsolvable, to alter the data or relax the constraints and pursue the resulting solutions. Such an embodiment could be enabled at any time, even before any previous equations had been sent to the solver. The embodiment would resemble the embodiment illustrated in
As is presented in
In one embodiment of the above functionality, the module may present to the user only the generating unit capable of producing the entire hypothetical generation amount, in addition to the unit's current output, at the lowest cost of all capable generating units, therefore allowing the user to sell it at the highest profit or to most cost efficiently produce instead of purchase. Other embodiments may present all generating units capable of producing the entire hypothetical generation amount, in addition to the units' current output, or may present all generating units capable of producing any additional output, from which the user can compile an amount equal to the hypothetical generation amount. Alternatively, it may be desirable for the module to allow the user to set thresholds of additional output that a generating unit must be capable of producing in order to be reported to the user. For example, a user could select X megawatts, 2X megawatts, and 4X megawatts as thresholds. In such an embodiment all generating units capable of producing at least X megawatts extra output would be shown on a list next to the price above which the user must sell that X megawatts to make a profit (or, alternatively, the price below which the user must purchase that X megawatts to make purchase more cost-efficient). Such an embodiment would give the same information for all generating units capable of producing 2X megawatts and 4X megawatts. In this way a user could easily select an additional amount of output to produce, from a fleet of generating units, in order to sell for a profit or avoid purchasing where purchasing would be cost inefficient.
Some or all of the previously discussed embodiments may be performed utilizing a computer or computer system. An example of such a computer or computer system is illustrated in
The above examples and disclosure are intended to be illustrative and not exhaustive. These examples and description will suggest many variations and alternatives to one of ordinary skill in this art. All of these alternatives and variations are intended to be included within the scope of the claims, where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims. Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of written description, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all claims which possess all antecedents referenced in such dependent claim.
This application claims priority to U.S. Provisional patent application No. 61/791,534 filed Mar. 15, 2013, the entire content of which is hereby incorporated by reference. Applicant has other co-pending applications directed to the energy market, namely: SYSTEMS AND METHODS FOR DEMAND RESPONSE AND DISTRIBUTED ENERGY RESOURCE MANAGEMENT, filed Feb. 9, 2011 and assigned application Ser. No. 13/024,158, the entire contents of which is hereby incorporated by reference. AUTOMATION OF ENERGY TRADING, filed Dec. 30, 2011 and assigned application Ser. No. 13/140,248, the entire contents of which is hereby incorporated by reference. CERTIFICATE INSTALLATION AND DELIVERY PROCESS, FOUR FACTOR AUTHENTICATION, AND APPLICATIONS UTILIZING SAME, filed Oct. 15, 2013 and assigned application Ser. No. 14/054,611, the entire contents of which is hereby incorporated by reference. A renewable energy credit management system and method, filed Feb. 10, 2014 and assigned application Ser. No. 14/176,590, the entire contents of which is hereby incorporated by reference. Systems and methods of determining optimal scheduling and dispatch of power resources, filed on Mar. 17, 2014 (Docket No. 017.2P-15315-US03), the entire contents of which is hereby incorporated by reference. Systems and methods for tracing electrical energy of a load to a specific generator on a power grid, filed on Mar. 17, 2014 (Docket No. 017.2P-15493-US03), the entire contents of which is hereby incorporated by reference. Systems and methods for trading electrical power, filed on Mar. 17, 2014 (Docket No. 017.2P-15565-US03), the entire contents of which is hereby incorporated by reference. Systems and methods for managing conditional curtailment options, filed on Mar. 17, 2014 (Docket No. 017.2P-15571-US03), the entire contents of which is hereby incorporated by reference. Systems and methods for tracking greenhouse gas emissions, filed on Mar. 17, 2014 (Docket No. 017.2P-15954-US02), the entire contents of which is hereby incorporated by reference. Systems and methods for parameter estimation for use in determining value-at-risk, filed on Mar. 17, 2014 (Docket No. 017.2P-15955-US02), the entire contents of which is hereby incorporated by reference. Systems and methods for managing transmission service reservations, filed on Mar. 17, 2014 (Docket No. 017.2P-15956-US02), the entire contents of which is hereby incorporated by reference. Systems and methods for interfacing an electrical energy end user with a utility, filed on Mar. 17, 2014 (Docket No. 017.2P-15958-US02), the entire contents of which is hereby incorporated by reference. Use of Demand Response (DR) and Distributed Energy Resources (DER) to mitigate the impact of Variable Energy Resources (VER) in Power System Operation, filed on Mar. 17, 2014 (Docket No. 017.2P-15959-US02), the entire contents of which is hereby incorporated by reference.
Number | Date | Country | |
---|---|---|---|
61791534 | Mar 2013 | US |