PLC FUNCTION BLOCK FOR AUTOMATED DEMAND RESPONSE INTEGRATION

• US 20120004786A1
• Filed: 05/09/2011
• Published: 01/05/2012
• Est. Priority Date: 06/30/2010
• Status: Active Grant

• Current Assignee: Siemens Corp. (Siemens AG)
• Original Assignee: Siemens Corp. (Siemens AG)
• Inventors: Lo, George, Gruenewald, Thomas, Ersch, Florian, Elpelt, Swen
• Granted Patent: US 8,670,875 B2
• Time in Patent Office: Days
• US Class Current: 700/296
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05B 2219/2642 Domotique, domestic, home control, automation, smart house
• CPC Class Codes: H02J 13/00028 involving the use of Internet protocols
• CPC Class Codes: H02J 3/04 for connecting networks of the same frequency but supplied from different sources
• 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 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 20/00 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

Abstract

Systems and methods are described that allow a Programmable Logic Controller (PLC) to receive Demand Response (DR) data and process the data in a PLC Function Block (FB). Embodiments provide a PLC demand response FB that solicits DR data and a demand response load manager FB that compares the DR data with predetermined demand constraints corresponding to electrical equipment. The demand constraints provide energy consumption strategies for buildings and factories.

Claims

1. A method for a Programmable Logic Controller (PLC) to control electrical equipment for a facility based on Demand Response (DR) data comprising:

communicating with a Demand Response Application Server (DRAS) over a communications network;

soliciting DR data from the DRAS;

receiving the DR data at the PLC; and

parsing the received DR data into a DR event level and level price.

2. The method according to claim 1 wherein communicating with the DRAS further comprises selecting a Uniform Resource Locator (URL) corresponding to the regional DRAS for the facility.

3. The method according to claim 2 wherein soliciting DR data from the DRAS further comprises generating a query based on an XML based schema which describes the data format for the DRAS.

4. The method according to claim 1 wherein DR event levels include normal, medium or high designations and a corresponding start and end time.

5. The method according to claim 1 wherein soliciting DR data further comprises selecting a DR data update frequency.

6. The method according to claim 1 further comprising configuring an energy conservation scheme for predetermined facility electrical equipment based on DR event levels and price.

7. The method according to claim 6 wherein configuring the energy conservation scheme further comprises:

selecting an output address register for a respective electrical equipment as a DR output register; and

for each DR output register, comparing a predefined DR event level for that electrical equipment with a current DR event level.

8. The method according to claim 7 further comprising setting a DR output register as either on or off depending on the outcome of the comparison.

9. A Programmable Logic Controller (PLC) demand response Function Block (FB) comprising:

an enabling input (EN) and an enabling output (ENO) for coupling with a PLC ladder rung for execution;

a client application configuration module configured with a Demand Response Application Server (DRAS) regional Uniform Resource Locator (URL) and a demand response data update frequency wherein an embedded client application script communicates over a communications network with the DRAS and solicits demand response event data from the DRAS depending on the update frequency;

a demand response data protocol receiver configured to receive current demand response event level (normal, medium, high) and level price data from the DRAS; and

a demand response data writer configured to write the received data to event level and event price address registers.

10. The PLC demand response FB according to claim 9 wherein the update frequency may be per unit time or per PLC program execution cycle.

11. The PLC demand response FB according to claim 9 wherein the event level further comprises start and end times for an event level.

12. The PLC demand response FB according to claim 9 wherein the embedded client application script communicates with the DRAS over the communications network using custom or standard Internet languages and protocols and scripting languages including HTML (Hypertext Markup Language), dynamic HTML (DHTML), Microsoft VBScript (Visual Basic Scripting Edition), Jscript, ActiveX, XML and Java.

13. The PLC demand response FB according to claim 9 wherein the received demand response data is parsed to retrieve the demand response event level and level price, and converted to a compatible PLC format.

14. A Programmable Logic Controller (PLC) demand response load manager Function Block (FB) comprising:

an enabling input (EN) and an enabling output (ENO) for coupling with a PLC ladder rung for execution;

a load address register assigned to an electrical equipment configured with a logic statement that compares a current demand response event level with a predefined demand response event level for that electrical equipment;

a demand response data reader configured to read demand response data from demand response data address registers; and

a demand response strategy engine configured to compare the demand response data read from the demand response registers with the logic statement and determine if the electrical equipment is shed or sequenced on.

15. The PLC demand response load manager FB according to claim 14 wherein the demand response data includes a demand response event level and level price.