CIM Topology & State. Alan McMorran B.Eng Ph.D. OGO Open Grid Systems

Transcription

1 CIM Topology & Alan McMorran B.Eng Ph.D 1

2 Topological vs Connectivity Node Breaker/Bus Branch modelling in the CIM 2

3 Two Levels of Detail Bus-branch has Powerflow buses (TopologicalNodes) Impedance branches and shunts Retained switches possible Node-breaker has Nodes (ConnectivityNodes) All (retained and non-retained) switches (Switch and sub-classes) Bus name markers (could be partially specified with Bus-branch model) Steady Hypothesis and Measurements (if not on non-retained switch terminals) work with both 3

4 Topological Nodes The Equipment model uses Connectivity Nodes and Terminals to define the connectivity between components This represents a Node-Breaker view of the network familiar to operations systems In planning applications it is more common to use a Bus-Branch model that represents buses that are computed by a Topological Processor CIM supports both views of the data 4

5 Topological Node Connectivity The Topological Node connectivity is defined in the same way as that of the Connectivity node A Terminal can have one or more Topological Node associations This is the Equipment on the edge of the Topological Node (e.g. EnergyConsumer, ACLineSegment, SynchronousMachine) Load A ACLineSegment Beta Terminals ACLineSegment Alpha Topological Node I 5

6 Profiles 6

7 Profiles Overview Using profiles involves separating single exchange definitions into multiple, dependent profiles The classes below part of a network exchange Synchronous Machine maxq minq rateds baseq r x Terminal name SvCompensator Sections continuoussections Topological Island name SvTapStep continuousposition SvPowerFlow p q VoltageLevel BaseVoltage nominalvoltage BusbarSection name SvVoltage v angle TopologicalNode name ACLineSegment name bch x r length GeneratingUnit nominalp maxoperatingp minoperatingp normalpf 7

8 Profile Group Three Profiles now define the same data Topology depends on Equipment depends on Topology (and Equipment) Equipment Topology Synchronous Machine maxq minq rateds baseq r x Terminal name VoltageLevel BusbarSection name ACLineSegment name bch x r length BaseVoltage nominalvoltage GeneratingUnit nominalp maxoperatingp minoperatingp normalpf Topological Island name TopologicalNode name Terminal SvPowerFlow p q SvTapStep continuousposition SvCompensator Sections continuoussections SvVoltage v angle 8

9 Why Separate? Profile separation can appear to complicate an already complex exchange definition The approach brings a number of benefits Profiles can be made smaller, simpler and more focussed Profiles can be combined and re-used in multiple configurations depending on the use-case The instance data itself is also kept modular This make large exchanges more manageable 9

10 Dependencies Profiles Variables Profile Steady Hypothesis Topology Profile Profiles Analog Measurement Profile Discrete Measurement Profile Profile Equipment Model Profile Profile Diagram Layout Profile 10

11 Use Cases 11

12 Estimator Use Case SCADA Analog Measurement Profile Discrete Measurement Profile Data Modeller Equipment Model Profile Topology Processor Topology Profile Estimator Steady Hypothesis Variables Profile Schedule Updater Schedule Values 12

13 Power Flow Use Case Data Modeller Equipment Model Case Builder Steady Hypothesis Network Model Builder Topology Power Flow Application Variables 13

14 Power Flow Use Case Data Modeller Equipment Model Steady Hypothesis Injection: active/reactive Voltage set point Tap position Case Builder Steady Hypothesis Limits Out of service Network Model Builder Topology Power Flow Application Variables 13

15 Power Flow Use Case Data Modeller Equipment Model Steady Hypothesis Injection: active/reactive Voltage set point Tap position Case Builder Steady Hypothesis Limits Out of service Network Model Builder Topology Topology Buses Retained switches Power Flow Application Variables 13

16 Power Flow Use Case Data Modeller Equipment Model Steady Hypothesis Injection: active/reactive Voltage set point Tap position Case Builder Steady Hypothesis Limits Out of service Network Model Builder Topology Topology Buses Retained switches Variables Islands Voltage: magnitude/angle Injection: active/reactive Power flow: active/reactive Tap position Power Flow Application Variables 13

17 Modularity of Data In frequent, full-model exchanges the majority of network data changes slowly As such having multiple datasets per exchange allows only those sets that have changed to be exchanged Equipment Topology 14

18 Multiple Datasets The Equipment changes infrequently Topology changes when the network configuration is altered changes in every exchange Equipment Topology Topology Topology 15

19 SSH vs Initially Variables were used for Output and Input This caused issues for users to reproduce the same results for a case. Power Flow solutions drifted Testing showed a requirement to differentiate between starting conditions and target values Steady Hypothesis solved this by defining additional parameters on the Equipment Topology is still used as output from topology processing on Node Breaker and input to Bus-Branch dependent processes 16

20 Topology & UML 17

21 Topology Profile 18

22 Variables AC 19

23 Variables Profile AC 20

24 Variables Sign Conventions SvPowerFlow Load sign convention is used i.e. positive sign means flow out from a TopologicalNode (bus) into the conducting equipment SvInjection The power injected into the bus in addition to injections from equipment terminals Positive sign means injection into the TopologicalNode (bus) 21

25 Topology & Variables Equipment Profile ConnectivityNode ConductingEquipment (ACLineSegment) Terminal Bus Name Marker TopologicalNode SvPowerFlow Topology Profile SvInjection SvVoltage Variable Profile 22

26 Planning buses In a bus-branch view of the network there are a number of buses and interconnecting branches 23

27 Planning buses In a bus-branch view of the network there are a number of buses and interconnecting branches 23

28 Operational Buses An operational view of the same network shows switches between the bus bar sections (ConnectivityNodes) Different switch configurations will result in different bus configurations 24

29 Operational Buses 25

30 Operational Buses 26

31 Operational Buses Depending upon the purpose of the exchange a utility may be required only to export these computed Topological Nodes rather than the detailed network 26

32 BusNameMarker A Bus Name Marker tied to a Busbar Section s Terminal means this computed Topological Node can be assigned a persistent name Bus Name Marker 27

33 28 Summary Node Breaker/Bus Branch modelling in the CIM

34 Summary The CIM Equipment profile defines the components in the network model and the connectivity With Connectivity Nodes this provides a node-breaker model Steady Hypothesis then defines the starting conditions The CIM Topology profile defines the computed buses for a bus-branch representation of the network and can be stored/exchanged with the node-breaker data The CIM Variables profile defines the results of network analysis as a stand-alone set of data with references into the Equipment and Topology 29