3.2 Current Distribution Planning and Operational Procedures

3.2.4 Typical Distribution Operations

Distribution operations do not typically have the same degree of automation as transmission systems. Some utilities can monitor the feeder currents in the substations (either directly or from a transmission SCADA), while others may be installing automated switches that can be used for automated fault location, fault isolation, and service restoration, in which a faulted feeder segment can be isolated and the remaining segments re-energized. 

The traditional methods of distribution operation now present challenges as utilities move toward larger DER penetration that will require greater integration among systems and access to improved real-time data to optimize operations so as to realize greater control of voltage, frequency, and other critical parameters as DERs introduce increased variability.

A typical distribution control room is shown in Figure 7.

Figure 7 : PG&E distribution control room (PG&E_opens_new_285_million_state-of-the-art_electric_control_center_in_fresno )

Utilities are implementing several critical systems to help monitor and analyze distribution operations:

• Supervisory control and data acquisition (SCADA) systems are used by control room operators to view information from and control connected devices in the field, usually by monitoring equipment located at substations or indirectly gathered from transmission SCADA systems.               
• Outage management systems (OMS) are used to coordinate information about forced and planned outages, emergency restoration and planned maintenance.  Integrates with geographic information systems (GIS) and other enterprise systems such as customer information systems.
• Distribution Management Systems (DMS) are used for near-real-time analyses, including with asset management and mobile job tracking. A DMS can also include power flow models and applications to optimize operation of controllable devices such as voltage regulators, capacitors and switching.
• Geographic Information Systems (GIS) are used both to store asset information and to display electronic maps of the distribution system showing the location of these assets.
• Distribution Automation (DA) equipment and systems, that includes field equipment that can provide fault location, isolation, and service restoration (FLISR).
• Advanced Metering Infrastructure (AMI) systems are used to collect metering data periodically from smart meters via remote communications. This system can also provide outage information and possibly voltage and other power system data.
• Customer Information System (CIS) includes all the relevant data about customers, including where they are interconnected to the grid.
• Load Management System (LMS) can issue load control commands either as direct commands or as pricing signals for demand response actions.
• Distributed Energy Resources Management System (DERMS) is a very new type of system that may store DER information, such as nameplate data and interconnection locations. It may also include analysis applications that could assess DER functionality at different locations, such as contingency analysis and conservation voltage reduction (CVR) status, etc.