The information of the network is as follows: The one-line diagram of a typical rural section of the Irish 38-kV distribution network was shown in above Figure. The feeders are supplied by one 31.5-MVA 110/38-kV transformer (capable of handling reverse power flows). The voltage at the grid supply point is assumed to be nominal. In the original configuration (no DG), the on-load tap changer at the substation has a target voltage of 1.078 pu (41 kV) at the busbar, well within the +-10% nominal voltage limits of Irish practice.
Best Wishes Silvio Miceli On Fri, Feb 10, 2012 at 23:07, Ray Zimmerman <[email protected]> wrote: > You haven't said which bus is your slack bus. Can I assume that it would > be the one labeled GSP? I don't see a slack generator at that bus. Is the > OLTC the *only* voltage control you have in the network? Is the voltage at > GSP fixed? > > -- > Ray Zimmerman > Senior Research Associate > 419A Warren Hall, Cornell University, Ithaca, NY 14853 > phone: (607) 255-9645 > > > > > On Feb 10, 2012, at 2:51 PM, Silvio Miceli wrote: > > I want to have an OLTC at slack bus only in order to control centrally the > network voltage (active network) as below figure. How can I compare the > results with and without OLTC? with changing tap ratio or with changing > voltage setpoints? > > <image.png> > > Best Wishes > > Silvio Miceli > > > On Fri, Feb 10, 2012 at 20:43, Ray Zimmerman <[email protected]> wrote: > >> In order to understand clearly what you are trying to compare, I would >> need to see the network topology. >> >> But, it both cases include the OLTC in the topology and in one case you >> are modifying the tap ratio to control voltage and in the other you are >> simply modifying the generator voltage setpoints, then the two solutions >> will not be equivalent. >> >> -- >> Ray Zimmerman >> Senior Research Associate >> 419A Warren Hall, Cornell University, Ithaca, NY 14853 >> phone: (607) 255-9645 >> >> >> >> >> On Feb 10, 2012, at 10:46 AM, Silvio Miceli wrote: >> >> Dear Ray, >> >> As far as I know, taking into account the voltage at slack bus as >> optimization variable is equal to have an OLTC. So, how can I compare the >> results with and without voltage control at slack? Can it be done either by >> changing the tap ratio or voltage limits? >> Best Wishes >> >> Silvio Miceli >> >> >> On Thu, Feb 9, 2012 at 18:57, Silvio Miceli <[email protected]>wrote: >> >>> Dear Ray, >>> >>> 1. Can I say MATPOWER's OPF considers the power factor angle of >>> generators as optimization variable? If not, how can I consider as >>> optimization variable? >>> >>> 2. Also, according to one of your replies to a post with regards to >>> considering the slack bus voltage as optimization variable, why you want to >>> implement OLTC in MATPOWER? In my idea, considering the slack bus as >>> optimization variable is equal to have an OLTC and consequently considering >>> the secondary voltage as optimization variable. Because usually the OLTC is >>> used in order to control the voltage of slack bus and in MATPOWER is >>> already considered as optimization variable. If I am not right, please let >>> me know? >>> >>> Best Wishes >>> >>> Silvio >>> >>> >>> >>> On Wed, Feb 8, 2012 at 17:47, Ray Zimmerman <[email protected]> wrote: >>> >>>> On Feb 8, 2012, at 10:01 AM, Silvio Miceli wrote: >>>> >>>> 1. What kind of generator has been taken into account in MATPOWER in >>>> Section 5.4.3 of MANUAL in order to consider the capability curve? >>>> >>>> >>>> It is simply intended to be a piecewise linear approximation to the >>>> kind of capability curve exhibited by many types of conventional >>>> generators, such as this >>>> one<http://images.pennnet.com/articles/hrm/cap/cap_coord%2003.gif> from >>>> Figure 2 in [1]. >>>> >>>> 2. I want to minimize losses instead of maximizing social welfare >>>> considering offers and bids. How can I do it in MATPOWER? >>>> >>>> >>>> The answer to this one is readily available in the list archives ... >>>> e.g. >>>> http://www.mail-archive.com/[email protected]/msg00817.html >>>> >>>> 3. How can I maximize profit for generators in MATPOWER instead of >>>> maximizing Social welfare? >>>> Also, by which formula I can obtain profits (for generators), revenue >>>> and cost in MATPOWER? Could you please address it? >>>> >>>> >>>> I'm not aware of a method to maximize profits, since that would involve >>>> an objective that is a function of price, a very unconventional type of >>>> optimization problem. You can compute revenue directly as the product of >>>> quantity and price, and the cost is available in the dispatch matrix >>>> returned by runmarket. See help idx_disp for a description of each column >>>> of the dispatch matrix. >>>> >>>> - Ray >>>> >>>> [1] >>>> http://www.hydroworld.com/index/display/article-display/353952/articles/hydro-review/volume-28/issue-2/feature-articles/system-protection/coordinating-generator-protection-and-controls-an-overview.html >>>> >>>> -- >>>> Ray Zimmerman >>>> Senior Research Associate >>>> 419A Warren Hall, Cornell University, Ithaca, NY 14853 >>>> phone: (607) 255-9645 >>>> >>>> >>> >>> >> >> > >
