Smart-grid adaptive power management method and system with power factor optimization and total harmonic distortion reduction

• US 10,530,156 B2
• Filed: 12/10/2018
• Issued: 01/07/2020
• Est. Priority Date: 09/15/2009
• Status: Active Grant

• Current Assignee: Volta Energy, Inc.
• Original Assignee: Volta Energy, Inc.
• Inventors: Kouroussis, Denis, Kulali, Emre
• Primary Examiner(s): Everett, Christopher E.
• Application Number:
  US16/214,400
• Publication Number:
  US 20190115757A1
• Time in Patent Office: 393 Days
• CPC Class Codes: G05B 13/021 in which a variable is automatically adjusted to optimise the performance
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05F 1/66 Regulating electric power
• CPC Class Codes: H02J 13/00034 the elements or equipment being or involving an electric power substation
• CPC Class Codes: H02J 2203/10 Power transmission or distribution systems management focussing at grid-level, e.g. load flow analysis, node profile computation, meshed network optimisation, active network management or spinning reserve management
• CPC Class Codes: H02J 3/01 Arrangements for reducing harmonics or ripples
• CPC Class Codes: H02J 3/144 Demand-response operation of the power transmission or distribution network
• CPC Class Codes: H02J 3/18 Arrangements for adjusting, eliminating or compensating reactive power in networks for adjustment of voltage H02J3/16
• CPC Class Codes: H02J 3/1892 the arrangements being an integral part of the load, e.g. a motor, or of its control circuit
• CPC Class Codes: H02M 1/4233 using a bridge converter comprising active switches
• CPC Class Codes: H02M 5/458 using semiconductor devices only
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving

Abstract

A method and system of power factor optimization and total harmonic distortion are provided under the premise of efficient power management and distribution on an electrical grid. The method and system include a novel optimization technique based on a novel current profiling methodology enabling real-time power management with power factor correction as a function of the optimization. The optimization can be performed under dynamic current constraints. When deployed on an electrical grid, the method and system can provide a new technique for power management targeting an efficiency of the electrical grid. The method and system can thus provide for reduced costs of energy production and reduced carbon emissions into the atmosphere.

Claims

1. A system for optimizing electrical power flow in an electrical distribution network, comprising:

a first plurality of intelligent load management controllers (ILMUCs) configured to control power delivery to a first plurality of electrical devices coupled to a first sub-grid of the electrical distribution network;

a second plurality of ILMUCs configured to control power delivery to a second plurality of electrical devices coupled to a second sub-grid of the electrical distribution network;

a power management server in communication with the first and second pluralities of ILMUCs configured to receive current profile information from said first and second pluralities of ILMUCs and generate therefrom a power library database containing a plurality of digital representations of a plurality of alternating current (AC) waveforms characterizing a plurality of AC currents flowing through the first and second pluralities of electrical devices under a plurality of different load conditions; and

a storage device configured to store the power library database,

wherein the power management server is further configured to determine first and second switching configurations of the first and second pluralities of ILMUCs using the power library database, and direct the first and second pluralities of ILMUCs to operate in accordance with the first and second switching configurations.

2. The system of claim 1, wherein the power management server is configured to determine and control the first and second switching configurations of the first and second pluralities of ILMUCs based on both historical current use pattern data and real-time current flow information measured and reported by the first and second pluralities of ILMUCs.

3. The system of claim 1, wherein the power management server is further configured to determine and control a system-level switching configuration based on the determined first and second switching configurations of the first and second pluralities of ILMUCs determined.

4. The system of claim 3, wherein the power management server is configured to determine the first, second, and system-level switching configurations iteratively to optimize the first switching configuration of the first sub-grid and/or the second switching configuration of the second sub-grid.

5. The system of claim 4, wherein optimizing the first switching configuration comprises maximizing the power factor of the first sub-grid and optimizing the second switching configuration comprises maximizing the power factor of the second sub-grid.

6. The system of claim 4, wherein optimizing the first switching configuration and/or second switching configuration comprises taking into consideration pricing information and/or supply and demand information.

7. The system of claim 3, wherein the power management server is configured to determine the first, second, and system-level switching configurations iteratively to optimize a system-level switching configuration.

8. The system of claim 7, wherein optimizing the system-level switching configuration comprises maximizing a power factor of the electrical distribution network as a whole.

9. The system of claim 7, wherein optimizing the system-level switching configuration comprises taking into consideration pricing information and/or supply and demand information.

10. The system of claim 1, wherein the power management server is further configured to:

determine a total current being drawn by the first plurality of electrical devices coupled to the first sub-grid;

calculate an available excess current that can be supplied to the first plurality of electrical devices; and

direct an ILMUC associated with one of the electrical devices that is coupled to the first sub-grid and operating as a load to deactivate and reactivate to serve as a source, if it is determined that the available excess current has become zero or negative.

11. The system of claim 1, wherein the plurality of digital representations of the plurality of AC waveforms is stored in the power library database as a plurality of Fourier transforms.

12. A method of controlling power flow in an electrical distribution network, comprising:

receiving, from a plurality of intelligent load management controllers (ILMUCs) associated with a plurality of electrical devices in an electrical distribution network, a plurality of alternating current (AC) current measurements characterizing a plurality of AC currents flowing through the plurality of electrical devices;

using the received AC current measurements, calculating and storing in a power library a plurality of digital representations of a plurality of AC waveforms characterizing the plurality of AC currents over one or more cycles;

comparing two or more waveforms from the power library to determine an optimum switching configuration; and

commanding the plurality of ILMUCs to switch in accordance with the optimum switching configuration,

wherein the optimum switching configuration, once implemented by the plurality of ILMUCs, maximizes a power factor of the electrical distribution network.

13. The method of claim 12, wherein the plurality of electrical devices includes at least one electrical device that is configurable to serve alternatively as a load and a source, and determining the optimum switching configuration includes reconfiguring one of the electrical devices that is serving as a load to serve as a source.

14. The method of claim 12, further comprising:

determining whether a current requirement of an additional load associated with an additional ILMUC is less than or greater than an available excess current that a system current supply can supply;

directing the additional ILMUC to activate the additional load if the current requirement is less than the available excess current; and

if the current requirement of the additional load is greater than the available excess current;

determining an updated optimum switching configuration using current profile information stored in the power library that will allow the additional load to be activated without exceeding the available excess current, activating the additional load, and commanding the plurality of ILMUCs, including the additional ILMUC associated with the additional load, to switch in accordance with the updated optimum switching configuration.

15. The method of claim 12, wherein:

receiving the plurality of AC current measurements characterizing the plurality of AC currents flowing through the plurality of electrical devices comprises receiving a plurality of AC current measurements from each ILMUC under a plurality of different load conditions, and

the power library comprises a 3D power library of current profiles for the plurality of electrical devices when operating under a plurality of different switching configurations.

16. The method of claim 12, wherein calculating and storing the plurality of digital representations of the plurality of AC waveforms characterizing the plurality of AC currents over one or more cycles comprises calculating and storing Fourier transforms of the plurality of AC waveforms, and comparing two or more waveforms from the power library to determine an optimum switching configuration comprises comparing the Fourier transforms of two or more of the waveforms.

17. The method of claim 12, further comprising synchronizing operation of the plurality of ILMUCs using a synchronization signal communicated over the electrical distribution network to facilitate the ILMUCs'"'"' implementation of the optimum switching configuration.

18. The method of claim 12, wherein each of the ILMUCs includes a wireless transmitter and receiving the plurality of AC current measurements characterizing the plurality of AC currents flowing through the plurality of electrical devices is completed over a wireless communications link.

19. The method of claim 12, wherein determining the optimum configuration includes taking into consideration utility supply and demand and/or pricing information.

20. The method of claim 12, wherein current available to be supplied by a system current supply coupled to the electrical distribution network is variable and determining the optimum switching configuration is repeated dynamically and in real time as the current available from the system current supply changes.