USING DEMAND SIDE RESOURCES TO PROVIDE FREQUENCY REGULATION

• US 20150295405A1
• Filed: 12/06/2013
• Published: 10/15/2015
• Est. Priority Date: 12/07/2012
• Status: Active Grant

• Current Assignee: Battelle Memorial Institute
• Original Assignee: Battelle Memorial Institute
• Inventors: Black, Jason W., Rehberg, Eric, Dvorsky, James E., McCullough, Jason J., Mansouri, Seyed A.
• Granted Patent: US 9,748,770 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: H02J 13/00004 characterised by the power network being locally controlled
• CPC Class Codes: H02J 13/00007 using the power network as support for the transmission
• CPC Class Codes: H02J 13/00016 using a wired telecommunication network or a data transmission bus
• CPC Class Codes: H02J 13/00024 by means of mobile telephony
• CPC Class Codes: H02J 13/00026 involving a local wireless network, e.g. Wi-Fi, ZigBee or Bluetooth
• CPC Class Codes: H02J 2310/12 The local stationary network supplying a household or a building
• CPC Class Codes: H02J 2310/58 The condition being electrical
• CPC Class Codes: H02J 3/00 Circuit arrangements for ac mains or ac distribution networks
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• CPC Class Codes: H02J 4/00 Circuit arrangements for mains or distribution networks not specified as ac or dc
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 20/12 Energy storage units, uninterruptible power supply [UPS] systems or standby or emergency generators, e.g. in the last power distribution stages
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 40/121 using the power network as support for the transmission
• CPC Class Codes: Y04S 40/124 using wired telecommunication networks or data transmission busses
• CPC Class Codes: Y04S 40/126 : using wireless data transmission

Abstract

In a direct load control system supporting frequency control of an electrical grid, at each electrical load of an aggregation of loads, a load status report is generated comprising an urgency value and a power level. At an aggregation dispatch controller, a dispatch signal is generated based on the generated load status reports and information indicative of electrical frequency. At each electrical load of the aggregation, the load is operated at the reported power level if the reported urgency value satisfies the dispatch signal and is not operated at the reported power level if the reported urgency value does not satisfy the dispatch signal.

Claims

1. A method comprising:

at each electrical load of an aggregation of loads, generating a load status report comprising an urgency value and a power level;

at an aggregation dispatch controller, generating a dispatch signal based on the generated load status reports and information indicative of electrical frequency; and

at each electrical load of the aggregation, operating the load at the reported power level if the reported urgency value satisfies the dispatch signal and not operating the load at the reported power level if the reported urgency value does not satisfy the dispatch signal.

2. The method of claim 1 wherein the information indicative of electrical frequency is one of an electrical frequency measurement and an Automatic Generation Control (AGC) signal.

3. The method of claim 1 wherein one of:

(i) the urgency value satisfies the dispatch signal if the urgency value is higher than the dispatch signal value;

(ii) the urgency value satisfies the dispatch signal if the urgency value is higher than or equal to the dispatch signal value;

(iii) the urgency value satisfies the dispatch signal if the urgency value is lower than the dispatch signal value; and

(iv) the urgency value satisfies the dispatch signal if the urgency value is lower than or equal to the dispatch signal value.

4. The method of claim 1 further comprising;

modifying the load operation based on detection at the load of an exceptional condition.

5. The method of claim 1 wherein the operating is performed for a next time interval and the method further comprises:

during the next time interval, acquiring information indicative of electrical frequency at a time resolution finer than the duration of the next time interval; and

adjusting the dispatch signal during the next time interval based on the acquired information.

6. The method of claim 1 wherein the operating is performed for a next time interval and the method further comprises:

during the next time interval, acquiring information indicative of electrical frequency at a time resolution finer than the duration of the next time interval; and

adjusting at least some of the load status reports during the next time interval based on the acquired information.

7. The method of claim 1 wherein an electrical load submits both a more urgent load status report and a less urgent load status report, and the operating at the electrical load comprises:

operating the load at the power level of the less urgent load status report if the urgency values of both the less urgent load status report and the more urgent load status report satisfies the dispatch signal;

operating the load at the power level of the more urgent load status report if the urgency value of the more urgent load status report satisfies the dispatch signal but the urgency value of the less urgent load status report does not satisfy the dispatch signal; and

not operating the load at all if the urgency value of the less urgent load status report does not satisfy the dispatch signal and the urgency value of the more urgent load status report does not satisfy the dispatch signal.

8. The method of claim 1 further comprising:

at the dispatch controller, adjusting the dispatch signal in one direction to compensate for an under-frequency condition indicated by the information indicative of electrical frequency;

or

at the dispatch controller, adjusting the dispatch signal in the opposite direction to compensate for an over-frequency condition indicated by the information indicative of electrical frequency.

9. A system comprising:

a dispatch controller configured to;

generate a dispatch signal based on information indicative of electrical frequency and based on load status reports received from an aggregation of electrical loads wherein each load status report comprises an urgency value and a power level, and

transmit the generated dispatch signal to the electrical loads of the population.

10. The system of claim 9 further comprising:

said aggregation of electrical loads, each electrical load of the aggregation configured to;

generate a load status report comprising an urgency value and a power level,

transmit the load status report to the dispatch controller,

receive the dispatch signal from the dispatch controller, and

operate at the reported power level if the urgency value satisfies the received dispatch signal and not operate at the reported power level if the urgency value does not satisfy the received dispatch signal.

11. The system of claim 10 further comprising:

a communication system via which the load status reports are conveyed from the electrical loads of the aggregation to the dispatch controller and via which the dispatch signal is conveyed from the dispatch controller to the electrical loads of the aggregation.

12. The system of claim 10 wherein one of:

(i) the urgency value satisfies the dispatch signal if the urgency value is higher than the dispatch signal value;

(ii) the urgency value satisfies the dispatch signal if the urgency value is higher than or equal to the dispatch signal value;

(iii) the urgency value satisfies the dispatch signal if the urgency value is lower than the dispatch signal value; and

(iv) the urgency value satisfies the dispatch signal if the urgency value is lower than or equal to the dispatch signal value.

13. The system of claim 10 wherein an electrical load of the aggregation is configured to generate two or more load status reports with different urgency values and to operate at the reported power of the least urgent load status report whose urgency value satisfies the received dispatch signal or to not operate at all if none of the urgency values satisfy the received dispatch signal.

14. The system of claim 10 wherein:

an electrical load of the aggregation is configured to generate its load status report comprising a priority vector including two or more elements for a corresponding two or more successive time intervals wherein each element includes an urgency value for the corresponding time interval and a power level for the corresponding time interval; and

the dispatch controller is configured to generate the dispatch signal based on the load status reports including the priority vector.

15. The system of claim 9 wherein the aggregation of electrical loads includes heating, ventilation, and air conditioning (HVAC) units.

16. The system of claim 9 wherein the aggregation of electrical loads includes hot water tanks.

17. The system of claim 9 wherein the aggregation of electrical loads includes dishwashers.

18. The system of claim 9 wherein the aggregation of electrical loads includes residential electrical loads.

19. The system of claim 9 wherein the information indicative of electrical frequency is one of an electrical frequency measurement and an Automated Generation Control (AGC) signal.

20. The system of claim 9 wherein the dispatch controller generates and transmits the dispatch signal for each successive time interval, and is further configured to:

during each time interval, acquire information indicative of electrical frequency at a time resolution finer than the duration of the time interval; and

adjust the dispatch signal during the time interval based on the acquired information.

21. The system of claim 9 wherein the dispatch controller is configured to:

adjust the dispatch signal in one direction to compensate for an under-frequency condition indicated by the information indicative of electrical frequency; and

adjust the dispatch signal in the opposite direction to compensate for an over-frequency condition indicated by the information indicative of electrical frequency.

22. A system comprising:

an aggregation of energy consuming loads wherein each energy consuming load of the aggregation includes electronics configured to generate a status report comprising a state indicating urgency and a consumption power value;

an aggregate dispatch controller comprising a computer configured to receive the status reports of the energy consuming loads of the aggregation and to compute an initial dispatch signal for a next time interval and to transmit the initial dispatch signal to the energy consuming loads of the aggregation;

wherein the electronics of each energy consuming load of the aggregation further decides whether to operate the energy consuming load over the next time interval at the consumption power value of its status report based on comparison of its state with the initial dispatch signal; and

wherein the aggregate dispatch controller is further configured to update the dispatch signal over the next time interval based on information acquired over the next time interval and to transmit the updated dispatch signal to the energy consuming loads of the aggregation, the electronics of each energy consuming load of the aggregation updating the decision to operate the energy consuming load over the next time interval at the consumption power value of its status report as a function of time based on comparison of the updated dispatch signal with its state.

23. The system of claim 22 wherein the electronics of each energy consuming load of the aggregation is further configured to update the state of its status report over the next time interval.

24. The system of claim 22 wherein the electronics of each energy consuming load are configured to generate the status report comprising a priority vector indicating its urgency as a function of time over a contiguous set of successive time intervals including the next time interval and at least one time interval after the next time interval.

25. The system of claim 24 wherein the priority vector includes a state element for each successive time interval.