  The electric power grid is one of the largest and most complex
infrastructures ever built by mankind. Modern civilization depends on it for
industry production, human mobility, and comfortable living. However, many
critical technologies such as the 60 Hz transformers were developed at the
beginning of the 20th century and have changed very little since then.1 The
traditional unidirectional power from the generation to the customer through
the transmission-distribution grid has also changed nominally, but it no longer
meets the need of the 21st century market energy customers. On one hand, 128m
US residential customers pay $15B/per month for their utility bill, yet they
have no option to select their energy supplier. In a world of where many
traditional industries are transformed by digital Internet technology (Amazon,
Ebay, Uber, Airbnb), the traditional electric energy market is lagging
significantly behind. A move towards a true digital grid is needed. Such a
digital grid requires a tight integration of the physical layer (energy and
power) with digital and cyber information to allow an open and real time market
akin to the world of e-commerce. Another major factor that is pushing for this
radical transformation are the rapidly changing patterns in energy resources
ownership and load flow. Driven by the decreasing cost in distributed solar,
energy storage, electric vehicle, on site generation and microgrids, the high
penetration of Distributed Energy Resource (DER) is shifting challenges
substantially towards the edge of grid from the control point of view. The
envisioned Digital Grid must facilitate the open competition and open
innovation needed to accelerate of the adoption of new DER technologies while
satisfying challenges in grid stability, data explosion and cyber security.
