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

• US 9,448,577 B2
• Filed: 09/23/2014
• Issued: 09/20/2016
• Est. Priority Date: 09/15/2009
• Status: Active Grant

• Current Assignee: Volta Energy, Inc.
• Original Assignee: Networked Power, Inc.
• Inventors: Kouroussis, Denis, Kulali, Emre
• Primary Examiner(s): Everett, Christopher E
• Application Number:
  US14/494,311
• Publication Number:
  US 20150019038A1
• Time in Patent Office: 728 Days
• Field of Search: None
• US Class Current: 1/1
• 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. An intelligent load management unit controller (ILMUC) for facilitating power factor correction (PFC) in an electrical power system having a plurality of other ILMUCs, said ILMUC comprising:

one or more switches configured to switch current from a system power supply to a load in an electrical power system, said one or more switches configurable to being switched in accordance with a plurality of different switching configurations and under a plurality of different system load conditions; and

a controller configured to determine and report a current waveform pattern descriptive of the waveform of current flowing through the ILMUC'"'"'s load over a single or multiple alternating current (AC) cycles to a central power management server, which determines, by comparing the reported current waveform pattern to current waveform patterns determined and reported by one or more ILMUCs of said plurality of other ILMUCs in the electrical power system associated with other loads, an optimum switching configuration for the one or more switches to adapt to, said optimum switching configuration comprising a switching configuration that maximizes a power factor of said electrical power system.

2. The ILMUC of claim 1, wherein:

said controller is configured to determine a plurality of different current waveform patterns under a plurality of different load conditions; and

said controller is configured to communicate said plurality of different current waveform patterns to said central power management server for use in determining different optimum switching configurations under different system load conditions.

3. The ILMUC of claim 2, wherein said controller is configured to determine and communicate the current waveform patterns to the central power management server in real time.

4. The ILMUC of claim 1, wherein said controller is configured to receive commands from said central power management server to activate and deactivate said load in real time depending on system load conditions.

5. The ILMUC of claim 4, wherein said controller is configured to receive power constraint information from a utility that affects whether said controller activates or deactivates said load.

6. The ILMUC of claim 1, wherein said controller is configured to receive commands from said central power management server to activate said load and configure and control said one or more switches in real time, in accordance with different optimum switching configurations under different system load conditions.

7. The ILMUC of claim 6, wherein said controller is configured to control and adjust a duty cycle or duty cycles of said one or more switches depending on which optimum switching configuration is being implemented.

8. The ILMUC of claim 1, wherein said controller is configured to respond to a command from said central power management server to activate said load under a second system load condition and configure and control said one or more switches in accordance with an updated optimum switching configuration, said updated optimum switching configuration comprising a switching configuration that is capable of delivering current from said system power supply to said load without exceeding an available excess system power supply current and maximizes the power factor of the electrical power system when implemented under the second system load condition.

9. The ILMUC of claim 8, wherein said controller is configured to modify a duty cycle or duty cycles of said one or more switches from a first duty cycle or duty cycles used when operating in accordance with said optimum switching configuration to a second duty cycle or duty cycles when operating in accordance with said updated optimum switching configuration.

10. A method of facilitating power factor correction (PFC) in an electrical power system containing a plurality of intelligent load management unit controllers (ILMUCs), comprising:

associating an intelligent load management unit controller (ILMUC) with a load in the electrical power system;

determining a current waveform pattern descriptive of a waveform of current flowing through said load over a single or multiple alternating current (AC) cycles using said ILMUC;

transmitting the determined current waveform pattern to a central power management server;

directing said ILMUC to adapt to an optimum switching configuration that is determined by the central power management server based on said determined current waveform pattern and current waveform patterns determined and transmitted to the central power management server from other ILMUCs of said plurality of ILMUCs in the electrical power system, said optimum switching configuration comprising a switching configuration that maximizes a power factor of the electrical power system; and

configuring one or more switches in said ILMUC to switch current to its load in accordance with said optimum switching configuration.

11. The method of claim 10, wherein configuring one or more switches in said ILMUC to switch current to its load in accordance with said optimum switching configuration comprises controlling a duty cycle or duty cycles of said one or more switches.

12. The method of claim 10, further comprising receiving at said ILMUC a command from the central power management server to not activate or deactivate the ILMUC'"'"'s load if it is determined that a current requirement of the ILMUC'"'"'s load would exceed an available excess current from asystem power supply.

13. The method of claim 12, further comprising receiving at said ILMUC an updated command from said central power management server to activate the ILMUC'"'"'s load and switch current to the ILMUC'"'"'s load in accordance with an updated optimum configuration capable of delivering current to said load without exceeding an available excess current from said system power supply.

14. The method of claim 10, wherein:

determining the current waveform of said load comprises determining a current waveform pattern descriptive of current flowing through the ILMUC'"'"'s load using said ILMUC under a first load condition; and

transmitting the determined current waveform pattern to the central power management server comprises transmitting the determined current waveform pattern to the central power management server; and

the optimum switching configuration determined by said central power management server is determined based on said determined current waveform pattern and other current waveform patterns determined by and reported to the central power management server by other ILMUCs configured in the electrical power system.

15. The method of claim 14, further comprising:

determining a second current waveform pattern descriptive of the current flowing through the ILMUC'"'"'s load under a second load condition using said ILMUC;

transmitting the determined second current waveform pattern to the central power management server;

receiving at said ILMUC a second command from said central power management server to switch current from a system power supply to the ILMUC'"'"'s load according to an updated optimum switching configuration, said updated optimum switching configuration determined based on said determined second current waveform pattern and other current waveform patterns determined and reported to the central power management server by other ILMUCs configured in the electrical power system; and

reconfiguring the one or more switches of said ILMUC to switch current to said load in accordance with said updated optimum switching configuration.

16. A method of implementing an optimum switching configuration in an electrical power system, comprising:

associating a plurality of intelligent load management unit controllers (ILMUCs) with a plurality of loads in an electrical power system;

determining a plurality of current waveform patterns descriptive of a plurality of waveforms of currents flowing through said plurality of loads over a single or multiple alternating current (AC) cycles using said plurality of ILMUCs;

communicating from said plurality of ILMUCs the plurality of determined current waveform patterns to a power management server; and

receiving commands from said power management server at one or more of said plurality of ILMUCs to implement an optimum switching configuration, said optimum switching determined based on the determined current waveform patterns communicated to said power management server and comprising a switching configuration, which when implemented, maximizes a power factor of the electrical power system.

17. The method of claim 16, wherein receiving commands from said power management server comprises receiving commands at one or more ILMUCs of said plurality of ILMUCs to activate one or more of their associated loads and receiving commands at one or more other ILMUCs to not activate deactivate one or more of their associated loads.

18. The method of claim 17, further comprising receiving power constraint information from a utility at one more ILMUCs that affects which ILMUCs of said plurality of ILMUCs are activated and which ILMUCs are not activated or deactivated.

19. A method of performing power factor correction in an electrical power system, comprising:

receiving and recording a plurality of current waveform patterns descriptive of a plurality of waveforms of currents flowing through a plurality of associated loads over a single or multiple alternating current (AC) cycles;

comparing combinations of current waveform patterns from the recorded plurality of current waveform patterns to determine one or more load combinations that will each satisfy an upper bound current constraint;

calculating combination of loads that will satisfy the upper bound current constraint and yield a highest power factor in the electrical power system; and

switching power from a system power source to loads of the load combination that was determined will yield the highest power factor.

20. The method of claim 19, further comprising:

receiving utility power constraint information; and

using said utility power constraint information to set said upper bound current constraint.

21. The method of claim 19, further comprising:

determining whether a non-critical load having a previously recorded current waveform pattern has been introduced to the electrical power system;

calculating an available excess system power supply current;

determining whether a current requirement of the introduced non-critical load exceeds the available excess system power supply current;

if it is determined that the current requirement of the non-critical load exceeds the available excess system power supply current, comparing combinations of recorded current waveform patterns, including the previously recorded current waveform pattern descriptive of the non-critical load, to determine a new switching configuration for switching power to a new combination of loads that includes said non-critical load, said new switching configuration being a switching configuration that satisfies said upper bound current constraint and maximizes the power factor of the electrical power system; and

implementing said new switching configuration to switch power to said new combination of loads.

22. The method of claim 21, wherein comparing combinations of previously recorded current waveform patterns is performed to determine a new optimum switching configuration each time a load in the electrical power system is deactivated or a new load is introduced to the electrical power system.