Researchers from Argonne National Laboratory’s Energy Systems division have been researching the impact of micro grids and analyzing ways to assimilate them more smoothly into the larger electric system. They have also examined the distribution system – the last leg of electricity’s journey from energy source to outlet.
“Traditionally, distribution systems have operated as passive networks, with one-way power flow from bulk energy sources to individual customers,” said Ning Kang, a scientist in Argonne’s Energy Systems division, who works with Principal Distribution Engineer Ravindra Singh. “But a micro grid – with its own distributed energy resources, like solar panels, can now inject power back into the grid. If that power flow isn’t properly managed, it can disrupt protection systems and other aspects of the distribution network.”
Their work has led them to the following conclusions regarding the strategies required to capitalize on this added power while avoiding problems:
- define micro grid generation within the power market – a structured way of selling power generated by the micro grids back to the grid is required whereby dispatch rules need to be established so that power is sent to the right place at the right time;
- update distribution protection systems – currently, devices that protect the distribution system from excessive current are typically only set up to serve a legacy grid with one-way power flow;
- improve monitoring for power quality – sensors and analytical tools may be required to provide high-resolution data on voltage and power quality; and,
- build better controls – applications for monitoring and diagnosing problems on the grid will require upgrades to handle increasing numbers of micro grids.