Transmission-Distribution Interface (TDI)

The physical point at which the upstream Bulk Power and Transmission System and the Distribution System interconnect, typically at one or several major substations.  In a conventional, highly bifurcated Power System, these were traditionally known as the Supply-side and Demand-side respectively.    

Power Systems that host growing volumes of Variable Renewable Energy (VRE) and Distributed Energy Resources (DER/CER) will experience significantly greater levels of Volatility, which can propagate upstream and downstream.  Ensuring system Adequacy, Security, Reliability and Cost-efficiency simultaneously will require much greater levels of dynamic inter-dependence across the TDI than in the past. 

Given the fast-evolving nature of power system transformation, the Future Grid Accelerator (FGA) has the status of a perpetual BETA version. Your suggestions for how each concept and definition may be enhanced are very welcome.

All feedback will be reviewed and considered for inclusion in subsequent updates.

Please provide your suggestions to improve to this definition: