Transcript David Holmberg, NIST SG Program, NIST - Events

Energy Profiles: BACnet Load Control,
61850, OpenADR, ZigBee, and C12.19
David Holmberg
BACnet Utility Integration Working Group leader
OASIS Profiles in Energy
June 9, 2009
Energy Profiles in context
• Service levels (the control strategy)
• Communications (info model)
– Load control (or price) communications
– Feedback to the grid side
– Or bids
BACnet background
• The BACnet protocol is all about building
controls and designed for monitoring
systems, managing schedules,
trending, controlling loads.
• BACnet has metering specific tools
like the Accumulator and
Pulse Converter objects.
• Ongoing work on a generic Meter
object to allow for interoperable access
from meters or meter gateways.
• BACnet has a specific
Load Control object (LCO)
BACnet Load Control object
• The Load Control object (LCO) provides an interface to
execute predetermined control actions and to view
current load shed status (example)
• Load Control object does not specify how the electrical
consumption is to be reduced or how consumption
baselines should be determined.
• Three parameters may be written:
– Requested_Shed_Level
– Start_Time
– Shed_Duration
• LCO can be in one of four states: inactive, shed pending,
shed compliant, or shed non-compliant.
• can be linked in a distributed, hierarchical fashion for
controlling complex combinations of electrical loads
Using the LCO
• LCO “Requested_Shed_Level” can be a level or % shed or kW
shed.
• LCO provides a way to communicate value to sub-systems/
devices, rather than commanding them with specific control
actions.
• LCO provides for status to give feedback—will you shed? Are
you shedding? (discovery, forecasting and DG)
• Implementing Prices-to-devices
• Do we use the LCO with a chiller? Isn’t it better to raise zone
temperature and let the existing control algorithm reduce
energy consumption?
– Temp Control (LC in terms of “don’t melt the chocolate”)
– Acceptable lighting reductions (service level)
– For unimportant loads (the pool pump) I’m not going to tell it to go to
50% power
• Has to be in the context of building operation.
ZigBee SEP
• ZigBee SEP details load control and price event
signals for AMI
• DR and LC Cluster, Apdx. D
– Load Control Event: issuerID, DeviceClass (to allow directing
event, e.g., HVAC, pool pump, lighting, EV, water heater,
appliance), startTime, Duration, CriticalityLevel, TempOffset,
TempSetpoint, AverageLoadAdjustmentPercentage, DutyCycle
– CancelEvent commands also
• Price Cluster
– Get and publish price commands
– Get Scheduled Prices
– PublishPrice format: providerID, Rate class, EventID, current
time, price, units, currency, start time, duration, price ratio,
alternate cost delivered.
61850, OpenADR, C12.19
• Marty Burns’ cross-analysis of IEC 61850, OpenADR, ANSI
C12.19 and LCO price and DR structures.
– “Common Objects for Pricing and Control Communications, EPRI 1018556”
• Begins with 61850 constructs and adds to them to include
pieces from other standards.
• Goal: develop real time price rate structures and control
signals in IEC 61850 formats for contributions to user groups
and standards organizations
• C12.19 Table 11:
– Direct load control: command sent to modify the state of control
points.
– Schedule: End Device programmed to modify state of control points at
specific dates, recurring dates, period of the week or event detection.
– Condition: End Device modifies state based on magnitudes of metered
quantities, price level (active tier), time of the day, period of the year
or any other condition based on a Single Line Math expression.
– Prepayment: End Device modifies state based on a remaining credit.
OpenADR cross comparison
• 61850 data classes
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Tariff
Schedule
Direct Load Control
Market
Bidder
Bid
Weather
Consumption Event
Energy Efficiency
IAQ