Hi Juliane, I don't have a lot of experience with this, but in one case when I approximated the Var limits, a crass way I used was to approximate the *Qgmax* was by ensuring that (*Pg*^2+*Qgmax*^2) be a reasonable percentage of the MVA rating (say 80 or 90%). If you want it to be accurate, you would probably have to use use the generator capability curve to decide the minimum and maximum Var limits. [image: Inline image 4]
If you know the maximum allowable stator losses (or an estimate of this), you can obtain *Qgmax* so as to ensure that, at rated voltage and the given *P*, the losses are within limits. [image: Inline image 2] And then, you could probably approximate *Qgmin* as *Qgmin* = - *Qgmax . * But in reality, the magnitude of *Qgmin *is usually less than the magnitude of *Qgmax*. I hope this helps. Shruti On Tue, Mar 1, 2016 at 5:53 AM, Selle, Juliane Regina < [email protected]> wrote: > Hi everyone, > > > I am working on building up a specific transmission system model > (220-450kV), so I need to write my own MATPOWER cases. I know the network > structure, so building up the branch matrix is not a problem. > I also know the installed capacities (power plants, renewables, ...) at > each node, which gives me the active power generation (in % of the > installed capacity). But I don't know how to set proper values for the > reactive power generation! Does anybody have experience on how to fit the > Q-limits to the active power generation? What is your suggestion? > > I don't have any data information on the reactive power by now at all and > I have no idea how to assess realistic reactive power limits. > > > Thanks, > > Juls > -- Regards, Shruti Dwarkanath Rao Graduate Research Associate, Arizona State University Co-Vice-Chair: IEEE PES ASU Student Chapter Tempe, AZ, 85281 650 996 0116
