The buses X and Y are connected to the rest of the system as they initially were, but there is now no branch connecting them directly. That branch is now connecting X’ and Y’ instead, creating an additional two-bus island.
Ray > On Jan 9, 2015, at 10:58 AM, Simone Cochi <[email protected]> wrote: > > 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 >> >> > >
