I am currently working in frequency control regulation through local response and I need to support the microgrid frequency by offering some tens MW from demand management.
for anyone interested, we may mean to share our knowledge.
We are considering to use Frequency Control Demand Management (FCDM) in our microgrid design as part of an artificial intelligent demand side management system
As far as I know, the constraint of 'generation/demand balance' refers to power system (or Micro Grid) frequency control, and thus if you can find an operation strategy for DER and DR sources to maintain this constraint, you will be able to control the frequency.
The following papers and links would be helpful for your research.