Apparatus and method for controlling a microgrid

• US 10,135,251 B2
• Filed: 12/31/2013
• Issued: 11/20/2018
• Est. Priority Date: 12/31/2013
• Status: Active Grant

• Current Assignee: Schneider Electric IT Corporation (Schneider Electric SE)
• Original Assignee: Schneider Electric IT Corporation (Schneider Electric SE)
• Inventors: Berard, Olivier
• Primary Examiner(s): Wells, Kenneth B
• Application Number:
  US15/108,901
• Publication Number:
  US 20160329713A1
• Time in Patent Office: 1,785 Days
• CPC Class Codes: H02J 2300/10 The dispersed energy generation being of fossil origin, e.g. diesel generators
• CPC Class Codes: H02J 2300/20 The dispersed energy generation being of renewable origin
• CPC Class Codes: H02J 2300/26 involving maximum power point tracking control for photovoltaic sources maximum power point systems in particular G05F1/67
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy wind motors F03D
• CPC Class Codes: H02J 2300/40 wherein a plurality of decentralised, dispersed or local energy generation technologies are operated simultaneously
• CPC Class Codes: H02J 3/241 The oscillation concerning frequency
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/388 Islanding, i.e. disconnection of local power supply from the network
• CPC Class Codes: H02J 3/40 Synchronising a generator for connection to a network or to another generator
• CPC Class Codes: H02J 9/066 characterised by the use of dynamo-electric machines H02J9/08 takes precedence
• CPC Class Codes: H02M 5/04 by static converters controlling transformers, reactors or choke coils, e.g. by tap changing H02P13/00
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

Aspects and embodiments described herein are directed to power interface devices and methods. In one aspect, a method for controlling a microgrid is provided. The microgrid includes a power interface device coupled to one or more microgrid elements comprising power sources and loads. The method includes determining, by the power interface device, a mode of operation of the microgrid, determining a power load of the one or more microgrid elements, and based on the mode of operation of the microgrid and the power load of the one or more microgrid elements, adjusting, by the power interface device, a frequency of a voltage of the power interface device to control the one or more microgrid elements.

Claims

1. A method for controlling a microgrid comprising a power interface device coupled to a plurality of microgrid elements comprising power sources and loads, the method comprising:

determining, by the power interface device, a mode of operation of the microgrid;

determining a power load of the plurality of microgrid elements; and

based on the mode of operation of the microgrid and the power load of the plurality of microgrid elements, adjusting, by the power interface device, a frequency of a voltage of the power interface device to communicate one or more instructions to at least one microgrid element of the plurality of microgrid elements.

2. The method of claim 1, further comprising:

receiving, by the plurality of microgrid elements, the voltage; and

based on the frequency, adjusting an input or output power of the plurality of microgrid elements.

3. The method of claim 2, wherein adjusting the frequency of the voltage of the power interface device comprises increasing the frequency of the voltage over a first threshold;

wherein receiving the voltage comprises receiving the voltage by a load of the plurality of microgrid elements; and

wherein adjusting the input or output power comprises increasing the input power of the load.

4. The method of claim 2, wherein adjusting the frequency of the voltage of the power interface device comprises increasing the frequency of the voltage over a second threshold;

wherein receiving the voltage comprises receiving the voltage by a power source of the plurality of microgrid elements; and

wherein adjusting the input or output power comprises decreasing the output power of the power source.

5. The method of claim 2, wherein adjusting the frequency of the voltage of the power interface device comprises decreasing the frequency of the voltage below a third threshold;

wherein receiving the voltage comprises receiving the voltage by a power source of the plurality of microgrid elements; and

wherein the adjusting the input or output power comprises increasing the output power of the power source.

6. The method of claim 2, wherein adjusting the frequency of the voltage of the power interface device comprises decreasing the frequency of the voltage below a fourth threshold;

wherein receiving the voltage comprises receiving the voltage by a load of the plurality of microgrid elements; and

wherein adjusting the input or output power comprises decreasing the input power of the load.

7. The method of claim 1, further comprising configuring upper and lower thresholds for the plurality of microgrid elements based on a type of the microgrid elements.

8. The method of claim 1, wherein the power interface device is coupled to an energy storage system, and wherein the method further comprises:

receiving by the energy storage system, the voltage; and

based on the frequency of the voltage, adjusting an input or output power of the energy storage system.

9. The method of claim 8, wherein the power interface device is coupled to a generator, and wherein the method further comprises:

receiving by the generator, the voltage; and

based on the frequency of the voltage, adjusting an output power of the generator.

10. A control system for a microgrid having a plurality of microgrid elements comprising:

a power interface device including;

a first power interface configured to couple to an electric utility;

a second power interface configured to couple to the microgrid;

a power conversion circuit coupled to the first power interface and the second power interface; and

a controller coupled to the power conversion circuit, the controller configured to;

determine a mode of operation of the microgrid;

detect an output power from the plurality of microgrid elements; and

based on the mode of operation of the microgrid and the output power from the plurality of microgrid elements, adjust a frequency of a voltage at the second power interface to communicate one or more instructions to at least one of the plurality of microgrid elements.

11. The control system of claim 10, wherein the control system is further configured to:

based on the frequency of the voltage, adjust an input or output power of the plurality of microgrid elements.

12. The control system of claim 10, wherein the control system is further configured to:

adjust the frequency of the voltage of the output power by increasing the frequency of the voltage over a first threshold; and

in response to increasing the frequency, increase the input power of a load coupled to the microgrid.

13. The control system of claim 10, wherein the control system is further configured to:

adjust the frequency of the voltage of the output power by increasing the frequency of the voltage over a second threshold; and

in response to increasing the frequency, decrease the output power of a power source of the microgrid.

14. The control system of claim 13, wherein the control system is further configured to:

adjust the frequency of the voltage of the output power by decreasing the frequency of the voltage below a third threshold; and

in response to decreasing the frequency, increase the output power of the power source.

15. The control system of claim 12, wherein the control system is further configured to:

adjust the frequency of the voltage of the output power by decreasing the frequency of the voltage below a fourth threshold; and

in response to decreasing the frequency, decrease the input power of the load.

16. The control system of claim 10, wherein the control system is further configured to configure upper and lower thresholds for the plurality of microgrid elements based on a type of at least one microgrid element of the plurality of microgrid elements.

17. The control system of claim 10, wherein the microgrid includes an energy storage system, and wherein the control system is further configured to:

based on the frequency of the voltage, adjust an input or output power of the energy storage system.

18. The control system of claim 17, wherein the microgrid includes a generator, and wherein the control system is further configured to:

based on the frequency of the voltage, adjust an output power of the generator.

19. A microgrid comprising:

a plurality of microgrid elements comprising a power source and a load; and

a power interface device comprising;

a first power interface configured to couple to an electric utility;

a second power interface configured to couple to the plurality of microgrid elements;

a power conversion circuit coupled to the first power interface and the second power interface; and

a controller coupled to the power conversion circuit, the controller configured to;

determine a mode of operation of the microgrid; and

based on the mode of operation of the microgrid, adjust a frequency of a voltage provided by the power interface device to communicate one or more instructions to at least one of the plurality of microgrid elements.

20. The microgrid of claim 19, wherein the load is configured to receive the voltage and based on the frequency adjust a power draw of the load, and wherein the power source is configured to receive the voltage, and based on the voltage adjust a power output level of the power source.