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Demand Response ArchitectureIntegration into the Distribution Management SystemABB Corporate Research, Raleigh, NC

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Outline

Demand Response Definition

Resources for DR

DMS-Based Architecture

Benefits of DR at DMS Level

Integration with AMI

Target MW Reduction

Validation

Concluding Remarks

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Demand ResponseDefinition

Shutting down the directly controllable loads of the

customers signed up for Direct Load Control (DLC)

Sending curtailment request signals to the customers and/or DR Service Providers signed up for Interruption and

Curtailment (I&C) DR

Sending emergency reduction request signals to the customers and/or DR Service Providers signed up for Emergency DR

Receiving and (possibly) accepting Curtailment Bids from

customers and/or DR Service Providers signed up for DR Bids

The objective is for the utility to achieve a Target MW Reduction in the total system demand at a future time interval

for certain duration of time, by executing one or more of the following actions:

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Demand ResponseResources

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Demand ResponseEngine

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Demand ResponseDMS-Based Architecture

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Demand ResponseWhy Integration with DMS?

DR assisted by the network model available at DMS:

� Efficient Congestion Relief: target areas of the distribution system that are congested (heavily loaded) more

� Voltage Constraints: reducing the loads in such a way that

the node voltages do not violate the maximum voltage limit

(when a feeder becomes lightly loaded)

� Reduction in Revenue Losses: achieve the target demand

reduction with less actual load lost on the customer’s side.

Example: reduced losses as a peripheral objective

� Coordination with other Distributed Energy Resources:

implementation at the DMS level where the economic

dispatch and control of DER is being performed

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Demand ResponseIntegration with AMI

• AMI can support the DR architecture because smart meter vendors are increasingly including disconnect switches

into the revenue meters ⇒⇒⇒⇒ meter can be used for polling consumption data as well as receiving DR control commands and other related signals

• Integration Challenges: meter data models, communication

standards, and typical DR messages

• C12.19 and IEC 62056-62: electricity, water and gas

• IEC 61968-9: meter model of CIM – better solution

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Demand ResponseTarget MW Reduction

System is continuously monitored at the DMS by calculating the forecasted demand, thereby estimating

the capacity margin for the future time intervals.

Capacity Margin = Demand Limit – Forecast Demand

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Demand ResponseChronological Steps

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Demand ResponseValidation

Not a big issue for DLC, but a concern for I&C.

Only after the ramp period that the utility can verify whether or not the requested demand reduction

actually took place.

This can be done by sending meter poll messages to

provide meter readings at the start of the sustained

response period.

A lack of sufficient compliance by the customers

would then force the utility to take drastic measures

in short notice. ⇒⇒⇒⇒ emergency DR signals with noticeably shorter advance notice (in the range of a

few minutes).

Last Resort: Load Shedding

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Concluding Remarks

� DR is a semi-emergency application that is triggered during

the times of peak load to reduce the total demand for certain duration of time.

� At the DMS level, DR can help achieve additional benefits

compared to a model-free solution implemented at the aggregator level for instance.

� At the DMS level, the network model is available and can be

incorporated into the DR solution.

� This would allow for taking account of network constraints

such as line congestion and node voltage limitations in the

overall solution. Furthermore, peripheral objectives such as minimizing the power losses can be achieved in parallel with

performing DR ⇒⇒⇒⇒ reduction of lost load as a result of DR.

� Lastly, when implemented at the DMS level, DR can be

incorporated into the broader problem of Grid Management where all DER is also taken into account.

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