3.2 Current Distribution Planning and Operational Procedures

3.2.5 Distribution Management Systems (DMS)

Since almost no monitoring of distribution feeders is done outside of the substation, the lack of available operational data is increasingly seen as a barrier to higher accuracy operations that would allow distribution systems to safely operate closer to maximum facility ratings, in a similar fashion to operational characteristics of the bulk high voltage transmission network.  Advanced distribution management systems (DMS), are an option that some utilities are evaluating or implementing that can consolidate functions of multiple of the above systems and are designed to incorporate a larger number of data sources as they become available from additional equipment installed at substations, distributed along feeders and from AMI where applicable.
Some of the components of DMS include:

• Distribution Network Model: A component of implementation of an DMS is commonly development of a distribution network model (DNM), which assembles a detailed distribution system topology, often importing data from multiple utility systems.  Utilizing system topology and available metering data, an ADMS can provide operators with near real-time state estimation across the network, an ability previously only available to operators of the bulk high voltage network.  State estimation calculations and methods used for distribution systems are distinct and different than those used for the high voltage system, meaning a separate system is needed.   Moving operations closer to the safe operating limits of the distribution system is aided significantly by knowing in real time how close each system element is to those limits. 
• This information can be used by operators or centralized automated control schemes to coordinate operation of equipment installed at substations, along feeders, or at customer sites such as capacitors, voltage regulators, FACTS devices, and smart inverters or other DERs. 
• Switching Contingency Analysis: Utilities often undertake switching operations between and among feeders, and leave some extra headroom when evaluating DER interconnections to accommodate these actions to ensure reliable operation if reconfiguration occurs due to an outage or planned maintenance.  This headroom is often applied as a rule of thumb without detailed studies.   Use of an DMS can readily produce contingency analysis using many scenarios in the operations horizon or in the planning horizon.  Use of valid system topology data will improve accuracy of these analyses and once again move the system operation closer to safe operating limits.