Hello everyone, I have problems when I have a piecewise linear cost function on some generators which increases slower after a break point as the power increases in my OPF. You can see an exemplary figure of the cost function here: [cid:[email protected]]
I have attached the input values I use for the generator and generator costs in one of the simulations here: [cid:[email protected]] It is a simulation where generators have to be started up to solve the grid problem. The generators in rows 2 and 7 are considered. Generator 2 has the cost function showed in the first figure. Up to the breakpoint that this function is minimally higher than that of generator 7, which has a completely linear cost function. After the breakpoint, the cost function of generator 2 increases only slightly, which is why the cost function is then lower than that of generator 7. To solve the OPF, one of the two generators or both of them together must increase the power by 0.00125. It is expected that generator 2 will provide this power. Instead, Generator 2 provides 0.011 (distance to breakpoint) and Generator 7 provides 0.0015. It almost looks like he used the cost the other way around in the OPF, because for Generator 2 the section with the highest cost per power is used. I have had similar results with other use cases that I have simulated. If I used a cost function that increases more steeply instead of increases slower after the breakpoint, then no problems occurred. I would be happy if you could help me where the problem lies. Is it a bug, is this a function that Matpower cannot solve or have I not parametrized the cost functions properly. I used Matpower6.0 in Matlab 2017a. Kind regards Tobias Müller -- [Mac HD:Users:koelling:Desktop:Unknown.png] Tobias Müller, M.Sc. Forschungsgruppe Betriebskonzepte und Sektorenkopplung Lehrstuhl für Elektrische Energieversorgungstechnik Bergische Universität Wuppertal Rainer-Gruenter-Str. 21 | 42119 Wuppertal Telefon: +49 202 3171 3291 | Fax: +49 202 439 1977 [email protected]<mailto:[email protected]> | www.evt.uni-wuppertal.de<http://www.evt.uni-wuppertal.de/>
