Assessing distributed energy resources for the energynet

• US 7,860,702 B1
• Filed: 09/17/2003
• Issued: 12/28/2010
• Est. Priority Date: 09/18/2002
• Status: Active Grant

• Current Assignee: Peter B. Evans
• Original Assignee: Peter B. Evans
• Inventors: Schumer, Steven E., Evans, Peter B.
• Primary Examiner(s): Jones; Hugh
• Assistant Examiner(s): Lo; Suzanne
• Application Number:
  US10/666,209
• Time in Patent Office: 2,659 Days
• Field of Search: 703/18, 703/13
• US Class Current: 703/18
• CPC Class Codes: G06F 30/367 Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods
• CPC Class Codes: H02J 2203/20 Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 40/20 Information technology specific aspects, e.g. CAD, simulation, modelling, system security

Abstract

An improved method for analyzing power systems; in particular, power systems that may incorporate distributed energy resources (DER), that provides a thorough determination of the potential for network performance improvement that DER could provide, independent of non-network benefits DER could provide. The method incorporates an Energynet dataset simulating the power system, integrating transmission and distribution elements together and capable of evaluating the impacts of additions of real energy sources and/or reactive energy sources anywhere in the network. Such energy source additions are evaluated for their impact on a broad set of performance measures. The specific DER projects that would realize that potential improvement in network performance are characterized as an Optimal DER Portfolio. Network performance improvement attributable to the Optimal DER Portfolio is quantified in engineering and financial terms.

Claims

1. A method for simulating an electric power network having a plurality of transmission-level buses and connected electrical elements and a plurality of distribution-level buses and connected electrical elements, the method comprising:

determining a model of the transmission-level buses and connected electrical elements, the model of the transmission-level buses including a plurality of transmission lines and a plurality of transmission electrical elements;

determining a model of the distribution-level buses and connected electrical elements, the model of the distribution-level buses including a plurality of distribution lines and a plurality of distribution electrical elements;

generating a single mathematical model by integrating the model of the transmission-level buses with the model of the distribution-level buses, wherein the single mathematical model further models the interdependency of the plurality of transmission lines and the plurality of transmission electrical elements included in the model of the transmission level buses and the plurality of distribution lines and the plurality of distribution electrical elements included in the model of the distribution-level buses;

simulating an operation of the electric power network with the single mathematical model; and

outputting data describing the simulated electric power network.

2. A method for analyzing an electric power network having a plurality of transmission-level buses and connected electrical elements and a plurality of distribution-level buses and connected electrical elements, the method comprising:

determining a model of the transmission-level buses and connected electrical elements, the model of the transmission-level buses including a plurality of transmission lines and a plurality of transmission electrical elements;

determining a model of the distribution-level buses and connected electrical elements, the model of the distribution-level buses including a plurality of distribution lines and a plurality of distribution electrical elements;

generating a single mathematical model by integrating the model of the transmission-level buses with the model of the distribution-level buses, wherein the single mathematical model further models the interdependency of the plurality of transmission lines and the plurality of transmission electrical elements included in the model of the transmission level buses and the plurality of distribution lines and the plurality of distribution electrical elements included in the model of the distribution-level buses;

assessing the modeled electric power network by characterizing power flow, losses, voltage profile and power factor; and

outputting data describing at least one of the condition and the performance of the simulated electric power network.

3. The method of claim 2, further comprising:

integrating models of theoretical distribution-level real and reactive energy sources connected to one or more of the plurality of distribution-level buses into the single mathematical model; and

observing impacts and effects across the simulated electric power network of the theoretical distribution-level real and reactive energy sources connected on one or more of the plurality of distribution-level buses.

4. The method of claim 2, further comprising:

integrating models of theoretical alternative topologies of the distribution-level portions of the electrical power network into the single mathematical model; and

observing impacts and effects across the simulated electrical power network of the alternative topologies of distribution-level portions of the network.

5. The method of claim 2, further comprising:

integrating additional models of theoretical distribution-level loads into the single mathematical model; and

observing impacts and effects of load growth across the simulated electrical power network due to the addition of theoretical distribution-level loads.

6. The method of claim 2, further comprising:

integrating models of theoretical transmission-level real and reactive energy sources connected to one or more of the plurality of transmission-level buses into the single mathematical model; and

observing impacts and effects across the simulated electric power network of the theoretical transmission-level real and reactive energy sources connected on one or more of the plurality of transmission-level buses.

7. The method of claim 2, further comprising:

integrating models of theoretical alternative topologies of the transmission-level portions of the electrical power network into the single mathematical model; and

observing impacts and effects across the simulated electrical power network of the alternative topologies of transmission-level portions of the network.

8. The method of claim 2, further comprising:

integrating additional models of theoretical transmission-level loads into the single mathematical model; and

observing impacts and effects of load growth across the simulated electrical power network due to the addition of theoretical transmission-level loads.

9. The method of claim 2, wherein the integrating models further comprises:

representing actual distribution-level buses and elements having an actual voltage and an actual topology with corresponding models of buses and elements characterized, at least in part, by representations of the actual voltages and the actual topologies of the distribution-level buses and elements.

10. A method for analyzing performance of a modeled electric power network having a plurality of transmission-level buses and connected electrical elements and a plurality of distribution-level buses and connected electrical elements, the method comprising:

determining a model of the transmission-level buses and connected electrical elements, the model of the transmission level buses including a plurality of transmission lines and a plurality of transmission electrical elements;

determining a model of the distribution-level buses and connected electrical elements, the model of the distribution level buses including a plurality of distribution lines and a plurality of distribution electrical elements;

generating a single mathematical model by integrating the model of the transmission-level buses with the model of the distribution-level buses, wherein the single mathematical model further models the interdependency of the plurality of transmission lines and the plurality of transmission electrical elements included in the model of the transmission level buses and the plurality of distribution lines and the plurality of distribution electrical elements included in the model of the distribution-level buses;

assessing the modeled electric power network by characterizing power flow, losses, voltage profile and power factor;

adding incremental real and reactive energy sources in locations of the modeled electric power network;

assessing by load-flow analysis the condition and performance of the modeled electric power network with the added incremental real and reactive energy sources;

determining whether the performance of the modeled electric power network is improved as a result of the added real and reactive energy sources;

determining a set of added real and reactive energy sources that yields a greatest improvement in network performance;

characterizing the set of added real and reactive energy sources as specific distributed energy resources; and

outputting data describing the set of added real and reactive energy resources.

11. The method of claim 10, further comprising, quantifying an improvement in performance of the modeled electric power network due to the set of added real and reactive energy sources.

12. The method of claim 10, wherein adding incremental real and reactive energy sources further comprises:

representing the energy sources with models of the energy sources characterized, at least in part, by values of corresponding electric power network actual bus location and actual voltage level;

adding to the single mathematical model the models of the energy sources at one of the distribution-level buses and transmission-level buses, wherein the models of real energy sources are added subject to actual limits appropriate for dispatchable demand reductions available on the electric power network, and the real energy sources with reactive energy sources are added subject to actual limits appropriate for generation at load sites within the electric power network.

13. The method of claim 10, wherein determining whether the performance of the modeled electric network is improved as a result of the addition of energy sources comprises:

considering selected characteristics of a reduction of real power losses and reactive power losses, improvement in voltage profile, improvement in voltage stability, improvement of load-serving capability, and avoidance of additions of electric elements connected to the network that would otherwise be required.

14. The method of claim 10, wherein characterizing the additions of real and reactive energy sources comprises:

creating a plurality of mathematical models each having both distribution-level buses and connected electrical elements and transmission-level buses and connected electrical elements under a plurality of network operating conditions;

determining the additions of models of real and reactive energy sources that achieve the greatest improvement in network performance of the modeled network under each set of operating conditions;

characterizing each incremental addition of real or reactive energy sources as a discrete generation project, dispatchable demand response project, or capacitor bank project; and

comparing results achieved under each set of operating conditions to derive model profiles for operation of each discrete added energy source model under each different set of operating conditions.

15. A computer readable medium comprising a computer program that when executed in a computer processor implements the steps of:

determining a model of the transmission-level buses and connected electrical elements, the model of the transmission-level buses including a plurality of transmission lines an a plurality of transmission electrical elements;

determining a model of the distribution-level buses and connected electrical elements, the model of the distribution-level buses including a plurality of distribution lines and a plurality of distribution electrical elements;

generating a single mathematical model by integrating the model of the transmission-level buses with the model of the distribution-level buses, wherein the single mathematical model further models the interdependency of the plurality of transmission lines and the plurality of transmission electrical elements included in the model of the transmission level buses and the plurality of distribution lines and the plurality of distribution electrical elements included in the model of the distribution-level buses;

integrating models of the distribution-level buses and connected electrical elements with models of the transmission-level buses and connected electrical elements into a single mathematical model;

simulating an operation of the electric power network with the single mathematical model;

calculating at least one of a condition and a performance of the simulated electric power network; and

outputting data describing at least one of a condition and a performance of the simulated electric power network.

16. The computer readable medium of claim 15, further comprising a computer program that when executed in a computer processor further implements the steps of:

integrating models of theoretical distribution-level sources of real and reactive energy sources connected to one or more of the plurality of distribution-level buses into the single mathematical model; and

calculating impacts and effects across the simulated electric power network of the theoretical distribution-level real and reactive energy sources connected on one or more the plurality of distribution-level buses.