SYSTEMS AND METHODS FOR CONTROLLING ENERGY USE IN A BUILDING MANAGEMENT SYSTEM USING ENERGY BUDGETS

• US 20130085614A1
• Filed: 09/30/2011
• Published: 04/04/2013
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Wenzel, Michael J., Drees, Kirk H.
• Granted Patent: US 8,843,238 B2
• Time in Patent Office: Days
• US Class Current: 700/277
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/38 Failure diagnosis
• CPC Class Codes: F24F 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/47 Responding to energy costs
• CPC Class Codes: F24F 11/58 using Internet communication
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 2120/00 Control inputs relating to users or occupants
• 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: G05B 2219/2642 Domotique, domestic, home control, automation, smart house
• CPC Class Codes: G05D 23/1923 using thermal energy, the cost of which varies in function of time
• CPC Class Codes: G05F 1/66 Regulating electric power
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06Q 30/0201 Market modelling; Market analysis; Collecting market data
• CPC Class Codes: G06Q 30/0202 Market predictions or forecasting for commercial activities
• CPC Class Codes: G06Q 30/0206 Price or cost determination based on market factors
• CPC Class Codes: H04L 12/14 Charging , metering or billing arrangements for data wireline or wireless communications
• CPC Class Codes: H04L 12/2803 Home automation networks
• CPC Class Codes: Y02P 90/84 Greenhouse gas [GHG] management systems
• CPC Class Codes: Y02P 90/845 : Inventory and reporting systems for greenhouse gases [GHG]

Abstract

Systems and methods for limiting power consumption by a heating, ventilation, and air conditioning (HVAC) subsystem of a building are shown and described. A feedback controller is used to generate a manipulated variable based on an energy use setpoint and a measured energy use. The manipulated variable may be used for adjusting the operation of an HVAC device.

Claims

1. A method for controlling power consumption by an HVAC system of a building, comprising:

using an energy use setpoint as a reference input for a feedback controller;

using a measured energy use as a measured input for the feedback controller; and

using the feedback controller to generate a manipulated variable output for adjusting the operation of an HVAC device.

2. The method of claim 1, wherein the feedback controller is used to generate the manipulated variable output during a demand limiting period.

3. The method of claim 1, wherein the measured energy use and the energy use setpoint are heat transfer rates or electrical power consumption rates.

4. The method of claim 1, wherein the manipulated variable output is a temperature setpoint for a second controller that directly controls the HVAC device.

5. The method of claim 1, wherein the manipulated variable output provides direct control over the HVAC device.

6. The method of claim 1, further comprising:

calculating the energy use setpoint using a zone temperature threshold value and a history of building zone temperatures from a previous demand limiting period, wherein the energy use setpoint is estimated to cause the highest building zone temperature at the end of a demand limiting period to be less than or equal to the zone temperature threshold value.

7. The method of claim 1, further comprising:

calculating the energy use setpoint by using a cost function that minimizes the financial cost of electrical power.

8. The method of claim 7, wherein the cost function comprises a probability that a particular energy use setpoint will cause the highest building zone temperature at the end of a demand limiting period to be less than or equal to a zone temperature threshold value and a financial cost associated with the probability.

9. The method of claim 1, wherein a thermal model of the building is not used to generate the manipulated variable output.

10. The method of claim 1, further comprising:

adjusting the energy use setpoint based on pricing data received from an energy provider.

11. A feedback controller for controlling power consumption by an HVAC system of a building, the controller comprising:

a processing circuit configured to generate a value of a manipulated variable for adjusting the operation of an HVAC device, wherein the processing circuit comprises;

an error analyzer configured to receive an energy use setpoint as a reference input and to receive a measured energy use as a measured input, wherein the error analyzer is further configured to compare the reference input and the measured input, and to use the comparison to determine an error value; and

an error corrector configured to receive the error value and to use the error value to generate the value of the manipulated variable.

12. The feedback controller of claim 11, wherein the error corrector is further configured to generate the manipulated variable during a demand limiting period.

13. The feedback controller of claim 11, wherein the measured energy use and the energy use setpoint are heat transfer rates or electrical power consumption rates.

14. The feedback controller of claim 11, wherein the manipulated variable is a temperature setpoint for a second controller that directly controls the HVAC device.

15. The feedback controller of claim 11, wherein the manipulated variable is a direct control command for the HVAC device.

16. The feedback controller of claim 11, wherein the processing circuit further comprises an energy use setpoint generator configured to calculate the energy use setpoint using a zone temperature threshold value and a history of building zone temperatures from a previous demand limiting period, wherein the energy use setpoint is estimated to cause the highest building zone temperature at the end of a demand limiting period to be less than or equal to the zone temperature threshold value.

17. The feedback controller of claim 11, wherein the processing circuit further comprises an energy use setpoint generator configured to calculate the energy use setpoint by using a cost function that minimizes the financial cost of electrical power used by the HVAC system, wherein the cost function comprises a probability that a particular energy use setpoint will cause the highest building zone temperature at the end of a demand limiting period to be less than or equal to a zone temperature threshold value and a financial cost associated with the probability.

18. The feedback controller of claim 11, wherein a thermal model of the building is not used by the processing circuit to generate the manipulated variable.

19. A method of adjusting an energy use setpoint for controlling power consumption by an HVAC system of a building, the method comprising:

comparing a building temperature measurement from the end of a demand limiting period to a temperature threshold; and

adjusting the energy use setpoint for a second demand limiting period based on the comparison.

20. The method of claim 19, wherein the energy use setpoint is a heat transfer rate or an electrical power consumption rate.