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Binding Constraints

Binding Constraints

This section describes interfaces used to retrieve binding constraints. There are several options for retrieval of binding constraints:

  • Binding constraints related to DRUC

  • Requested Operating Day

  • Binding constraints related to HRUC

  • Requested End Hour

  • DAM shadow prices for binding constraints

The request message would use the following message fields:

Message Element Value
Header/Verb get
Header/Noun BindingConstraints
Header/Source Market participant ID
Header/UserID ID of user
Request/OperatingDate

Day of the Report

For DRUC & DAM MarketType
Request/MarketType DAM/DRUC/HRUC
Request/EndTime

End time of interest

For HRUC MarketType

The corresponding response messages would use the following message fields:

Message Element Value
Header/Verb reply
Header/Noun BindingConstraints
Header/Source ERCOT
Reply/ReplyCode Reply code, success=OK, error=ERROR or FATAL
Reply/Error Error message, if error encountered
Payload/ BindingConstraints

The following diagram describes the structures that are used for the retrieval of binding constraints and shadow prices:

BindingConstraints Structure

BindingConstraint Structure

The following elements are used to report binding constraints:

  • Name of the constraint

  • Value that exceeded limit

  • Limit defined for constraint

  • Maximum shadow price

  • Delivery time

  • RUC type (DRUC, HRUC, and DAM)

  • Contingency Name

  • Contraint ID

  • Station name which contingency is from

  • Station name which contingency is to

  • Station voltage which contingency is from

  • Station voltage which contingency is to

  • Violation amount

The following is an XML example:

<ns1:BindingConstraints xmlns:ns0="http://www.ercot.com/schema/2007-05/nodal/eip/il"
    xmlns:ns1="http://www.ercot.com/schema/2007-06/nodal/ews">
    <ns1:BindingConstraint>
        <ns1:name>PNHNDL</ns1:name>
        <ns1:value>3063.0</ns1:value>
        <ns1:limit>3063.0</ns1:limit>
        <ns1:shadowPrice>0.655</ns1:shadowPrice>
        <ns1:deliveryTime>2017-09-21T01:00:00-05:00</ns1:deliveryTime>
        <ns1:hourEnding>1</ns1:hourEnding>
        <ns1:rucType>DAM</ns1:rucType>
        <ns1:contingencyName>BASE CASE</ns1:contingencyName>
        <ns1:constraintID>1</ns1:constraintID>
        <ns1:fromStationKV>0.0</ns1:fromStationKV>
        <ns1:toStationKV>0.0</ns1:toStationKV>
        <ns1:ViolationAmount>0.0</ns1:ViolationAmount>
    </ns1:BindingConstraint>
</ns1:BindingConstraints>