Thank you doctor for the answer. I have another question about the method you proposed to minimize the flow on a certain branch http://www.mail-archive.com/[email protected]/msg03558.html, once I connect the line to the the two dummy busses, the original X and Y busses are isolated?
2015-01-09 15:41 GMT+01:00 Ray Zimmerman <[email protected]>: > I believe your two objectives are conflicting. For example, you can always > reduce losses by reducing the power sent to a charging station. I think you > simply want positive benefit functions for your dispatchable loads, where > the benefit is greater than the cost at the single supply bus (plus cost of > losses). If you use a uniform constant marginal benefit for all charging > points, then you will maximize the total charging power in the system, and > implicitly do it in a way that minimizes the losses for that charging > pattern, since it is supplied through a single source with positive cost > (i.e. increasing losses would increase that cost). However, if it is > important to somehow balance the charging availability across the network, > rather than just maximize the total, then you will need to use decreasing > marginal benefit functions (whose minimum still exceeds the cost at the > source). In this case, you will be making a tradeoff between loss > minimization (which tends to reduce cost) and “balancing” which will tend to > increase cost. > > Hope this helps, > > Ray > > > On Jan 8, 2015, at 5:41 AM, Simone Cochi <[email protected]> wrote: > > Dear Matpower community, > > I’m working on modulation of electric vehicle charging points connected to a > distribution grid. My first aim is to guarantee the maximum available power > for every charging station in a range between 43 and 129 kW. To implement > this target the cost function for every charging point (that is modeled as a > dispatchable load) should be decreasing with the power available to the > charging point. > > My second target is to try to nullify the reverse power flow from the > distribution grid to the HV network. While doct. Zimmerman suggested to put > a cost on the primary substation with the procedure explained here > https://www.mail-archive.com/[email protected]/msg03440.html, I found > easier and effective for the network I’m studying to add a constraint on the > the slack bus with Pg>0 and a constant generator cost which value is: > > COSTslack = n*f(129) > > where n is the number of charging point and f the cost function of the > single charging station. > > I would like to know if there is a way to guarantee with this cost functions > that this solution is also the one with the minimum losses. I read the > F.A.Q. on the subject and it states to put the same constant gencost on all > the generators, so in my case I have to put the same costant gencost on the > slack bus and on the charging points but doing so the maximum available > power to the stations won’t be guaranteed. > > Any suggestions? > > Simone > >
