Common Information Model
The Common Information Model (CIM) is a large body of standards published by the International Electrotechnical Commission (IEC) specifying data exchange messages and protocols for the electrical industry.
As a gross simplification, the three main standard series are:
- IEC 61970 electric transmission
- IEC 61968 electric distribution
- IEC 62325 energy markets
The current stable version, CIM16, comprises IEC 61970 v29, IEC 61968 v12.08, and IEC 62325 v3.01a. The next stable version, CIM 17 is expected to be published in 2018.
These standards are embodied as a UML data model, freely available by joining the CIM Users Group (CIMUG). The roughly 90 packages, comprising over 1500 classes, describe most objects of interest to electrical power engineers.
The data model and an XML/RDF file format specification allows exchange of detailed information between participating systems.
Data Model Packages
The following is a very brief overview of the general grouping of classes into packages.
The most fundamental packages are Core, Common, and Wires, which together allow a node-breaker network model to be created. The Topology package adds the classes needed for bus-branch network models. The DC package is separate, but similar to Wires and Topology for DC networks. The Equivalents package provides for foreign networks at network boundaries or simplified models within a network. Calculated and measured values are modeled with the StateVariable and Meas packages respectively. The OperationLimits, Faults, Operation, and Work packages model utility operations. The Metering, PaymentMetering and Customers packages deal with services, meter reading, aggregation, recording and billing. Non-electric description and specification of equipment is handled by the Assets and AssetInfo packages. Several Market... packages model forecast power flows and monetary exchanges between buyers. Many, many other packages handle such things as diagrams, machine dynamics, SCADA, inter-control center communications, and so on.