Systems and methods for detecting changes in energy usage in a building

• US 9,196,009 B2
• Filed: 06/23/2011
• Issued: 11/24/2015
• Est. Priority Date: 06/22/2009
• Status: Active Grant

• Current Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Drees, Kirk H., Wenzel, Michael J.
• Primary Examiner(s): Charioui, Mohamed
• Assistant Examiner(s): Zhang, Ruihua
• Application Number:
  US13/167,571
• Publication Number:
  US 20110257911A1
• Time in Patent Office: 1,615 Days
• Field of Search: 702/61, 702/62, 702/57, 702/130, 702/188, 700/286, 700/291, 700/295, 705/10, 705/35, 705/37, 621/26, 621/27, 621/29, 340/584, 709/224
• US Class Current: 1/1
• CPC Class Codes: G01R 21/133 by using digital technique
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05B 17/02 electric
• CPC Class Codes: G05B 2219/2642 Domotique, domestic, home control, automation, smart house
• CPC Class Codes: G06Q 10/0637 Strategic management or analysis, e.g. setting a goal or target of an organisation; Planning actions based on goals; Analysis or evaluation of effectiveness of goals
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: G06Q 50/163 Real estate management
• CPC Class Codes: H02J 13/00001 characterised by the display of information or by user interaction, e.g. supervisory control and data acquisition systems [SCADA] or graphical user interfaces [GUI]
• CPC Class Codes: H02J 13/00004 characterised by the power network being locally controlled
• CPC Class Codes: H02J 13/00006 characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
• CPC Class Codes: H02J 13/00016 using a wired telecommunication network or a data transmission bus
• CPC Class Codes: H02J 2203/20 Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
• CPC Class Codes: H02J 2310/12 The local stationary network supplying a household or a building
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• 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: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 20/00 Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
• CPC Class Codes: Y04S 20/20 End-user application control systems
• CPC Class Codes: Y04S 20/221 General power management systems
• CPC Class Codes: Y04S 20/222 : Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y04S 40/12 : characterised by data transport means between the monitoring, controlling or managing units and monitored, controlled or operated electrical equipment
• CPC Class Codes: Y04S 40/124 : using wired telecommunication networks or data transmission busses
• CPC Class Codes: Y04S 40/20 : Information technology specific aspects, e.g. CAD, simulation, modelling, system security

Abstract

A computer system for use with a building management system for a building includes a processing circuit configured to automatically identify a change in a building'"'"'s energy usage model based on data received from the building management system. The processing circuit may be configured to communicate the identified change in the static factor to at least one of (a) a module for alerting a user to the identified change and (b) a module for initiating an adjustment to the energy model for a building in response to the identified change.

Claims

1. A building management system in a building, comprising:

a plurality of sensors distributed throughout the building and configured to measure one or more environmental variables, the plurality of sensors comprising a temperature sensor that measures a temperature variable and a humidity sensor that measures a humidity variable, wherein the plurality of sensors generate sensor data representing the measured environmental variables;

a controller comprising a communications interface configured to receive the sensor data from the plurality of sensors and a processing circuit coupled to the communications interface;

the processing circuit comprising an enthalpy module configured to calculate an enthalpy variable using the temperature variable and the humidity variable;

the processing circuit further comprising a regression analysis module configured to generate an energy usage model for the building using the calculated enthalpy variable, wherein energy usage model includes one or more model coefficients based on the sensor data;

the processing circuit further comprising a facility monitoring module configured to automatically identify a change in the building'"'"'s energy usage model using new sensor data received from the temperature sensor and the humidity sensor, wherein the energy usage model expresses the building'"'"'s energy consumption as a function of one or more predictor variables and the one or more model coefficients, and wherein the change in the building'"'"'s energy usage model is a change in at least one of the model coefficients resulting from the new temperature sensor data and humidity sensor data;

wherein the facility monitoring module comprises;

a test statistic module configured to compare a coefficient of the energy usage model to a calculated energy model coefficient for a more recent time period and to use a difference between the model coefficients to create a test statistic,

a critical value module configured to determine whether the test statistic exceeds a critical value and to determine that an identified change in the building'"'"'s energy usage model has occurred in response to the test statistic exceeding the critical value, and

a reporting module configured to communicate the identified change in the building'"'"'s energy usage model to a module for initiating an adjustment to the energy model for the building in response to the identified change;

the processing circuit further comprising a building control module that uses the adjusted energy model to generate and transmit control parameters via the communications interface; and

one or more mechanical building devices that affect an environmental variable inside the building by operation of one or more electro-mechanical or hydraulic elements in response to the transmitted control parameters.

2. The building management system of claim 1, wherein, to conduct the comparison, the processing circuit creates the test statistic representing at least one of:

(a) the difference between the model coefficients,

(b) an F-statistic that is related to the difference between the model coefficients, and

(c) a Z-statistic that is formed by standardizing an F-statistic that is related to the difference between the model coefficients;

wherein the processing circuit determines autocorrelation of a plurality of such test statistics for varying windows of time; and

wherein the processing circuit uses the autocorrelation to determine whether the baseline model has changed in a way that affects energy usage.

3. The building management system of claim 2, wherein the processing circuit using the autocorrelation to determine whether the baseline model has changed in a way that affects energy usage comprises:

the processing circuit calculating the critical value such that the probability that any given test statistic is greater than the critical value matches a predefined probability of falsely determining that the baseline model has changed in a way that affects energy usage;

wherein the critical value is calculated using a cumulative probability distribution inverse approximated via Monte Carlo simulation of the test statistics for the varying windows of time; and

wherein the samples used to approximate the inverse are simulated by simulating the actual process used to detect the change with a randomly generated model or are simulated from a multivariable normal distribution.

4. The building management system of claim 1, wherein the comparison is conducted after installation of an energy conservation measure and while the system is in a measurement and verification reporting period.

5. The building management system of claim 1, wherein the processing circuit is further configured to determine and report an additional cost or savings attributable to the identified change in the building'"'"'s energy use model;

wherein the processing circuit is further configured to use the additional cost or savings to determine a non-routine adjustment to the baseline model estimated to provide an accurate calculation of savings attributable to an energy conservation measure;

wherein the energy use factor is a static factor.

6. The building management system of claim 1, wherein the comparison is conducted on based on data from a time period prior to installation of the energy conservation measure and wherein the energy use model will serve as a baseline model for a measurement and verification process.

7. A building management system in a building, comprising:

a plurality of sensors distributed throughout the building and configured to measure one or more environmental variables, the plurality of sensors comprising a temperature sensor that measures a temperature variable and a humidity sensor that measures a humidity variable, wherein the plurality of sensors generate sensor data representing the measured environmental variables;

a controller comprising a communications interface configured to receive the sensor data from the plurality of sensors and a processing circuit coupled to the communications interface;

the processing circuit comprising an enthalpy module configured to calculate an enthalpy variable using the temperature variable and the humidity variable;

the processing circuit further comprising a regression analysis module configured to generate a resource consumption model for the building using the calculated enthalpy variable, wherein resource consumption model includes one or more model coefficients based on the sensor data;

the processing circuit further comprising a facility monitoring module configured to automatically identify a change in the building'"'"'s resource consumption model using data received from the temperature sensor and the humidity sensor, wherein the resource consumption model expresses the building'"'"'s resource consumption as a function of one or more predictor variables and the one or more model coefficients, and wherein the change in the building'"'"'s resource consumption model is a change in at least one of the model coefficients resulting from the new temperature sensor data and humidity sensor data;

wherein the facility monitoring module comprises a test statistic module configured to compare a coefficient of the energy usage model to a calculated energy model coefficient for a more recent time period and to use a difference between the model coefficients to create a test statistic;

the processing circuit further comprising a reporting module configured to communicate the identified change in the building'"'"'s resource consumption model a module for initiating an adjustment to the resource consumption model for the building in response to the identified change;

the processing circuit further comprising a building control module that uses the adjusted resource consumption model to generate and transmit control parameters via the communications interface; and

one or more mechanical building devices that affect an environmental variable inside the building by operation of one or more electro-mechanical or hydraulic elements in response to the transmitted control parameters.

8. The building management system of claim 7, wherein the resource consumption model corresponds to at least one of water usage, gas usage, and electrical energy usage.