One model to run the distribution grid

By Doug Houseman

In the 1960s and 1970s, the transmission operators implemented complete models of their systems to support a wide range of activities. These activities included forecasting, operations, protection, state estimation and dynamic rating of equipment to name a few. Up to the second models are available for any portion of the transmission grid and the uses of these models continue to grow as new sensors, and modeling tools are created. The transmission grid has both grown in complexity since the 1970s and in reliability. Very few outages for customers are related to issues in the transmission grid.

With the push to embed more and more supply resources into the distribution grid, as well as the push for demand side management, the operation on the distribution grid will approach the complexity of the operation of the transmission grid. But we continue to allow the distribution grid to primarily operate in a passive, autonomous fashion. Many utilities have dispatch centers that manage crews and manual operations. To a large extent the SCADA and models that the transmission operations depend on do not exist in distribution. Substation automation and distribution automation will solve the issue with the current lack of information. That portion of operating the grid is well understood and well underway.

The problem is not with the field equipment or software to manage the grid, rather the issue is with the lack of the model that represents the distribution grid, the key construct that transmission developed in the 1970s.