Methods and systems for coordinating the control of HVAC units

• US 9,568,924 B2
• Filed: 07/16/2012
• Issued: 02/14/2017
• Est. Priority Date: 03/03/2008
• Status: Active Grant

• Current Assignee: Vigilent Corporation
• Original Assignee: Vigilent Corporation
• Inventors: Federspiel, Clifford C.
• Primary Examiner(s): Ali, Mohammad
• Assistant Examiner(s): Karim, Ziaul
• Application Number:
  US13/549,879
• Publication Number:
  US 20120283881A1
• Time in Patent Office: 1,674 Days
• Field of Search: 700276-278, 700/299, 700/29, 165/201, 340/514
• US Class Current: 1/1
• 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 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: G05D 22/02 characterised by the use of electric means
• CPC Class Codes: G05D 23/1931 to control the temperature of one space
• CPC Class Codes: H05K 7/20836 Thermal management, e.g. server temperature control

Abstract

A control strategy for heating, ventilating, and air-conditioning (HVAC) units used to condition the environment in data centers and other commercial buildings such as retail stores with an open-plan design is provided to coordinate the operation of the actuators of the HVAC units. A supervisory controller receives feedback signals from a plurality of environmental sensors and uses a set of references values to determine control signals to the actuators of the HVAC units. A pseudoinverse of a transfer function matrix G may be used to determine the control signals from errors in the feedback signals relative to the reference signals.

Claims

1. A method of controlling a plurality of environmental maintenance modules of a system using a plurality of sensors, the method comprising:

operating the system using first values of operational parameters for the environmental maintenance modules;

receiving, at a supervisory controller of the system from a first subset of sensors of the plurality of sensors, a first set of environmental measurements, each environmental measurement being from a respective one of the first subset of sensors;

receiving at the supervisory controller a first status indicator for a first of the plurality of environmental maintenance modules, the first status indicator distinct from the environmental measurements, wherein the first status indicator indicates an operational status of the first environmental maintenance module, the operational status comprising information related to whether the first environmental maintenance module is in an “

on”

or “

off”

state, or is in a failure mode, wherein the first status indicator indicates the first environmental maintenance module is in a failure mode;

receiving a second status indicator for a second of the plurality of environmental maintenance modules, the second status indicator indicating that the second environmental maintenance module is in an “

on”

state;

determining differences between the first set of environmental measurements and a plurality of reference values, each difference being between a respective environmental measurement and a corresponding reference value; and

calculating an updated value for at least one operational parameter of the second of the environmental maintenance modules based on the first status indicator and at least one of the differences, wherein the first and second environmental maintenance modules are coupled to a common controlled space.

2. The method of claim 1, wherein the failure mode indicated by the first status indicator indicates the first environmental maintenance module is not working.

3. The method of claim 1, wherein the operational parameter of the second environmental maintenance module is one of a fan speed or a supply air temperature setpoint.

4. The method of claim 1, wherein the operational parameter of the second environmental maintenance module is a return air temperature setpoint.

5. The method of claim 1, wherein the operational parameter of the second environmental maintenance module is a chilled water valve position.

6. The method of claim 1, wherein the common controlled space is determined by a collection of values of a transfer function matrix, G, corresponding to the operational parameter of the environmental maintenance module, wherein the values in the collection of values of G are larger than values of G not in the collection.

7. The method of claim 1, further comprising:

receiving, by the supervisory controller, a status indicator of a sensor; and

using the status indicator of the sensor in calculating the value of the operational parameter of the second environmental maintenance module.

8. The method of claim 7 wherein the status indicator of the sensor indicates that the sensor has failed.

9. The method of claim 1, wherein at least one of the sensors is a temperature sensor.

10. The method of claim 1, wherein at least one of the sensors is a pressure sensor.

11. The method of claim 1, wherein the information provided in the operational status includes at least one of an operational level of the first environmental maintenance module, or a connection status between the first environmental maintenance module and the supervisory controller.

12. The method of claim 1, further comprising:

setting to zero a parameter corresponding to the first status indicator into the calculation of the value for the operational parameter of the second of the environmental maintenance modules.

13. A system comprising:

a plurality of environmental maintenance modules;

a supervisory controller communicatively linked to the environmental maintenance modules;

a plurality of sensors communicatively linked to the supervisory controller; and

a memory comprising instructions which when executed cause the supervisory controller to;

operate the system using first values of operational parameters for the environmental maintenance modules;

receive from a first subset of the plurality of sensors a first set of environmental measurements, each environmental measurement being from a respective one of the first subset of sensors;

receive a first status indicator, distinct from any of the environmental measurements, from a first of the plurality of environmental maintenance modules;

identify an operational status of the first environmental maintenance module based on the first status indicator, the operational status comprising information related to whether the environmental maintenance module is in an “

on”

or “

off”

state or is in a failure mode, wherein the first status indicator indicates the first environmental maintenance module is in a failure mode;

receiving a second status indicator for a second of the plurality of environmental maintenance modules, the second status indicator indicating that the second environmental maintenance module is in an “

on”

state;

determine differences between the first set of environmental measurements and a plurality of reference values, each difference being between a respective environmental measurement and a corresponding reference value; and

calculate an updated value for at least one operational parameter of the second of the environmental maintenance-modules based on the first status indicator and at least one of the differences, wherein the first and second environmental maintenance modules are coupled to a common controlled space.

14. The system of claim 13, wherein the failure mode indicated by the first status indicator indicates the first environmental maintenance module is not working.

15. The system of claim 13, wherein at least one of the sensors is one of a pressure sensor or a temperature sensor.

16. A system of claim 13, wherein the operational parameter of the second environmental maintenance modules is one of a fan speed or a supply air temperature setpoint.

17. The system of claim 13, wherein the operational parameter of the second environmental maintenance modules is one of a chilled water valve, or a return air temperature setpoint.

18. The system of claim 13, wherein the calculation of the value of the operational parameter of the second environmental maintenance module uses M largest singular values of a transfer function matrix, G, M being a positive integer.

19. The system of claim 13, wherein the supervisory controller receives a status indicator of a sensor, and uses the status indicator of the sensor for calculating the value of the operational parameter of the second environmental maintenance module.

20. The system of claim 13, wherein the common controlled space is determined by a collection of values of a transfer function matrix, G, corresponding to the parameter of the environmental maintenance module, wherein the values in the collection of values of G are larger than the values of G not in the collection.

21. The system of claim 13, wherein the information provided in the operational status includes at least one of an operational level of the first environmental maintenance module, or a connection status between the first environmental maintenance module and the supervisory controller.

22. A method of controlling a plurality of environmental maintenance modules of a system using a plurality of sensors, the method comprising:

operating the system using first values of operational parameters for the environmental maintenance modules;

receiving, at a supervisory controller from a first subset of sensors of the plurality of sensors, a first set of environmental measurements, each environmental measurement being from a respective one of the first subset of sensors;

receiving at the supervisory controller a first status indicator for a first of the plurality of environmental maintenance modules, the first status indicator distinct from the environmental measurements, wherein the first status indicator indicates an operational status of the first environmental maintenance module, the operational status comprising information related to whether the first environmental maintenance module is working properly, wherein the first status indicator indicates the first environmental maintenance module is not working properly;

receiving a second status indicator for a second of the plurality of environmental maintenance modules, the second status indicator indicating that the second environmental maintenance module is in an “

on”

state;

determining differences between the first set of environmental measurements and a plurality of reference values, each difference being between a respective environmental measurement and a corresponding reference value; and

calculating an updated value for at least one operational parameter of a second of the environmental maintenance modules based on the first status indicator and at least one of the differences, wherein the first and second environmental maintenance modules are coupled to a common controlled space, and wherein the calculation sets to zero a parameter corresponding to the first status indicator when the first environmental maintenance module is not operating correctly.

23. The method of claim 22, wherein calculating the value for the operational parameter of the second of the environmental maintenance modules uses a transfer function matrix, G, wherein the transfer function matrix has one dimension being a total number of operational parameters of the environmental maintenance modules and the other dimension being the number of sensors.

24. The method of claim 23, wherein calculating the value for the operational parameter of the second of the environmental maintenance modules further uses M largest singular values of the transfer function matrix G.

25. The method of claim 24, further comprising:

modifying the transfer function matrix G using the status indicator before the M largest singular values are determined.