3.6 Distribution Resource Planning With DER Systems

3.6.3 Distribution Management Systems and Distribution Automation

Distribution systems have primarily relied on long term planning (3-5 year time frame) rather than any real-time operations. It is for that reason that distribution planning has always been based on “worst-case” scenarios of highest load during peak times, with distribution operations relying on autonomous actions by load tap changers, voltage regulators, and capacitor banks to handle real-time situations.

However, new technologies are now available that can more effectively manage real time operations, particularly for emergency situations. For instance, many distribution operation centers can receive SCADA information from substations, including data on feeder breaker and current.  Outage management systems can use this information from substations and add more detailed information from smart meters to detect and report power outages. Distribution automation equipment can be installed that can respond rapidly to faults, including locating the faulted feeder segment, isolating that faulted segment and then restoring service to other segments on that feeder. This fault location, isolation, and service restoration (FLISR) function can dramatically decrease the number and length of outages.

Distribution utilities are also starting to implement Distribution Management Systems (DMS) that can perform power-flow-based studies and contingency analysis on much shorter time-frames, such as a week ahead or even within an hour of real-time. As more data can be retrieved from smart meters and from DER systems, utilities can help determine the most effective and efficient settings for their equipment (as well as DER systems) in near-real-time, rather than relying only on the long term plans. The resulting understandings will also be used to identify possible tariff or market-based financial actions.