Fast( one to two cycle)control of load unbalance, could be identified and controlled, on the basis of, the limiting value of negative sequence component, and could be achieved by reducing it to the limiting value, refer my paper,' Microprocessor based load balance control (transformer or alternator)............using symmetrical component'.

Thanks for your contribution M. Desai

Practice of ancillary services providers differ depending on market structure and ownership. However, stakeholders are more or less limited to the DSO, ancillary service provider and of course customers. The practice in general is based on annual contracts about specific capacity (overhead) and operating costs (any used power for balancing). For the down regulation, service providers (in this case would be storage) similar scheme is followed. This is part of the unit commitment problem and can be minimized by optimal power flow.

I recommend the following article:

Chu, W.-C.; Yi-Ping Chen, "Feasible Strategy for Allocating Cost of Primary Frequency Regulation," Power Systems, IEEE Transactions on , vol.24, no.2, pp.508,515, May 2009

doi: 10.1109/TPWRS.2008.2012185

Donald, Valuing load balancing has been an issue for me since I published my first paper, "Tie Riding Freeloaders--The True Impediment to Transmission Access," Public Utilities Fortnightly, 1989 December 21.  Several of these papers are on my web site, LivelyUtility.com

Thanks Hatem. I can't find that paper anywhere, would you mind providing a link ?

Thanks Mark.

http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4797822&queryText%3D10.1109%2FTPWRS.2008.2012185

Plese, have a look to: 

http://www.sciencedirect.com/science/article/pii/S0378775314010520

Best regards,

  Raúl.

I filed comments last week with FERC on this issue.  In the library on my website (LivelyUtility.com) under the FERC Comment section.  Look for Docket No. AD14-3.