System and method for controlling states of a DC and AC BUS microgrid

• US 9,568,903 B2
• Filed: 07/14/2014
• Issued: 02/14/2017
• Est. Priority Date: 04/15/2010
• Status: Active Grant

• Current Assignee: Science Applications International Corporation
• Original Assignee: Science Applications International Corporation
• Inventors: Miller, Landon Cabell Garland
• Primary Examiner(s): Laughlin, Nathan L
• Application Number:
  US14/330,685
• Publication Number:
  US 20140324235A1
• Time in Patent Office: 946 Days
• US Class Current: 1/1
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: H02J 2300/10 The dispersed energy generation being of fossil origin, e.g. diesel generators
• CPC Class Codes: H02J 2310/10 The network having a local or delimited stationary reach
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 4/00 Circuit arrangements for mains or distribution networks not specified as ac or dc
• CPC Class Codes: Y02E 40/70 Smart grids as climate change mitigation technology in the energy generation sector
• CPC Class Codes: Y04S 10/12 Monitoring or controlling equipment for energy generation units, e.g. distributed energy generation [DER] or load-side generation

Abstract

Systems and methods are described herein for controlling the states of a microgrid module. The microgrid module includes transformers and/or power converters necessary for modifying the input AC or DC power sources to meet the required characteristics of the output power. The microgrid module further comprises a control software module installed on a microgrid computer. The control software module receives data associated with the operating state of the microgrid module. The control software module can access rules associated with each microgrid module operating state to determine whether the microgrid module must transition to a different operating state. If a transition is appropriate, the control software module can apply commands to transition the microgrid module to a different operating state. The control software module can continue to monitor the microgrid module to determine when another state transition is appropriate.

Claims

1. An apparatus for managing a change in an operating state of a micro grid to manage flow of power between one or more distributable power sources, a utility power grid and one or more loads comprising:

a microgrid computer comprising;

a computer readable storage device storing a first operating state business parameter rule associated with a first operating state of the microgrid and a second operating state business parameter rule associated with a second operating state of the microgrid and a third operating state business parameter rule associated with a third operating state of the microgrid; and

a control software module applying the first operating state business parameter rule to data received from a circuit layer of the microgrid to determine a first command and applying the first command to transition the microgrid from the first operating state to a second operating state;

the control software module further applying the second operating state business parameter rule to data received from the circuit layer to determine a second command and applying the second command to transition the microgrid from the second operating state to a third operating state;

the control software module further applying the third operating state business parameter rule to data received from the circuit layer to determine a third command and applying the third command to transition the microgrid from the third operating state to a fourth operating state;

the circuit layer comprising;

an AC input bus coupled to an AC output bus and a first converter;

a DC bus coupled to a second converter;

the first converter coupled to the DC bus;

the second converted coupled to the AC output bus;

at least a first sensor coupled to the DC bus, the at least a first sensor sending data to the control software module, wherein the AC input bus and the DC bus are coupled to one or more distributable power sources and a utility power grid;

the control software module receiving the at least a first sensor data and generating one of the first, second or third commands in response thereto when the data meets one of the first, second or third operating state business parameter rules;

at least a first controllable element receiving the first command to transition the microgrid from the first operating state to the second operating state, wherein the first operating state of the microgrid is an off state wherein no power is available at the microgrid from the one or more distributable power sources or the utility power grid and the second operating state of the microgrid is a disabled state wherein power is available to the microgrid from the one or more distributable power sources and the utility power grid, but no power is flowing therethrough, the at least a first controllable element powering up the DC bus in response to the first command;

at least a second controllable element receiving the second command to transition the microgrid from the second operating state to the third operating state, wherein the third operating state of the microgrid is a grid neutral state wherein power is available to the utility power grid and the one or more loads through the microgrid from the one or more distributable power sources but only power from the utility power grid is passing through the microgrid to the one or more loads; and

the at least a second controllable element receiving the third command to transition the microgrid from the third operating state to the fourth operating state, wherein the fourth operating state of the microgrid is an on grid state which includes the microgrid directing power from the one or more distributable power sources to at least one of the utility power grid and the one or more loads.

2. The apparatus of claim 1, wherein the on grid state is a grid offset state, wherein the microgrid directs power upstream to the utility power grid and to one or more loads.

3. The apparatus of claim 1, wherein the on grid state is a peak shaving state, wherein the microgrid directs power upstream to the utility power grid from the one or more distributable power sources during predetermined periods of peak power demand.

4. The apparatus of claim 1, wherein the on grid state is an average offset state, wherein the microgrid directs power upstream to the utility power grid from the one or more distributable power sources to reduce a predetermined average maximum power usage of the utility power grid.

5. The apparatus of claim 1, wherein the on grid state is a power conditioning state, wherein the microgrid directs power upstream to the utility power grid from the one or more distributable power sources to address a quality of power supply issue including at least one of jitter, cycle phasing and phase frequency adherence.

6. The apparatus of claim 1, wherein the first controllable element is a switch coupled to the AC input bus.

7. The apparatus of claim 1, wherein the first controllable element is a switch coupled to the DC bus.

8. The apparatus of claim 1, wherein the circuit layer comprises a second sensor coupled to the AC input bus.

9. The apparatus of claim 1, wherein the DC bus is coupled to one or more distributable power sources selected from the group consisting of a solar energy source, a wind energy source, a biofuel energy source, and a power storage device.

10. A method for managing a change in an operating state of a microgrid to manage flow of power between one or more distributable power sources, a utility power grid and one or more loads comprising:

storing in a computer readable storage device a first operating state business parameter rule associated with a first operating state of the microgrid, wherein the first operating state of the microgrid is an off state wherein no power is available at the microgrid from the one or more distributable power sources;

receiving, at a control software module, first data from at least a first sensor in a circuit layer of the microgrid;

applying, by the control software module, the first operating state business parameter rule to the received data to determine a first command;

applying, by control software module, the first command to transition the microgrid from the first operating state to a second operating state, wherein the second operating state of the microgrid is a disabled state wherein power is available to the microgrid from the one or more distributable power sources, but no power is flowing therethrough;

invoking, by the control software module, a set up procedure for the second operating state wherein the set up procedure includes powering up a component of the micro grid;

monitoring, by the control software module, the microgrid while the microgrid operates in the second operating state;

receiving, at a control software module, second data from the at least a first sensor;

applying, by the control software module, a second operating state business parameter rule to the received second data to determine a second command;

applying, by the control software module, the second command to transition the microgrid from the second operating state to a third operating state, wherein the third operating state of the microgrid is a bypass state wherein power is available to the microgrid from the one or more distributable power sources but only power from the utility power grid is passing through the microgrid to the one or more loads;

invoking, by the control software module, a set up procedure for the third operating state;

monitoring, by the control software module, the microgrid while the microgrid operates in the third operating state;

receiving, at a control software module, third data from the at least a first sensor;

applying, by the control software module, a third operating state business parameter rule to the received third data to determine a third command;

applying, by the control software module, the third command to transition the microgrid from the third operating state to a fourth operating state, wherein the fourth operating state of the microgrid is a grid on state which includes the microgrid directing power from the one or more distributable power sources to at least one of the utility power grid and the one or more loads;

invoking, by the control software module, a set up procedure for the fourth operating state; and

monitoring, by the control software module, the microgrid while the microgrid operates in the fourth operating state.

11. The method of claim 10, wherein the on grid state is a grid offset state, wherein the third data triggers the third command for the microgrid to direct power upstream to the utility power grid and to one or more loads.

12. The method of claim 10, wherein the on grid state is a peak shaving state, wherein the third data triggers the third command for the microgrid to direct power upstream to the utility power grid from the one or more distributable power sources during predetermined periods of peak power demand.

13. The method of claim 10, wherein the on grid state is an average offset state, wherein the third data triggers the third command for the microgrid to direct power upstream to the utility power grid from the one or more distributable power sources to reduce a predetermined average maximum power usage of the utility power grid.

14. The method of claim 10, wherein the on grid state is a power conditioning state, wherein the third data triggers the third command for the microgrid to direct power upstream to the utility power grid from the one or more distributable power sources to address a quality of power supply issue including at least one of jitter, cycle phasing and phase frequency adherence.

15. The method of claim 10, wherein the circuit layer comprises:

an AC input bus coupled to an AC output bus and a first converter;

a DC bus coupled to a second converter;

the first converter coupled to the DC bus;

the second converted coupled to the AC output bus;

the least a first sensor coupled to the DC bus, the at least a first sensor sending data to the control software module, wherein the AC input bus and the DC bus are coupled to one or more distributable power sources and a utility power grid.

16. The method of claim 15, wherein the first command transitioning the microgrid from the first operating state to the second operating state causes the microgrid to power up the DC bus.

17. The method of claim 15, wherein the second command transitioning the microgrid from the second operating state to the third operating state causes the microgrid to receive power via the DC bus.