I don't see any reason that MATPOWER should not be able to solve power flow problems for low voltage networks, as long as the R/X ratios of the lines are not too large.
-- Ray Zimmerman Senior Research Associate 419A Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On Nov 23, 2011, at 5:10 AM, <[email protected]> <[email protected]> wrote: > Dear Sir or Madame, > > I'm a student at the Otto-von-Guericke University in Magdeburg, Germany and > I'm about to get started in using Matpower for some network analysis problems > in Low Voltage networks (230V rms). I try to calculate how the voltages at > the busses/nodes change by adding more decentral energy sources like > photovoltaics. I tried to use Matpower and have got some problems. It would > be very nice if you could give me some advice in solving my modelling > problem. I'd be very happy about any help. > > > At first view Matpower seems to be usefull for solving these problems. At > first step I tried to build a network of only to busses (#01 to represent a > energy source (transformator from medium voltage to low voltage, modelled as > a generator) (#02: 100kW Load) in order to get to know Matpower itself. But I > found a problem, which I can't solve right now: > I have to set a baseMVA-Value and a base voltage. So I decided for some > values. The lower the chosen MVA-Value the bigger the chance that the > iteration won't converge. But in Low-Voltage I can't use some GVA or > TVA-Values just in order to get it work, can't I?! > For the Impedance of the branch, connecting both busses, I calculated values > for a 300m piece of cable. Than I devided the Impedance-values by the > baseImpedance in order to get p.u. Impedances as claimed by Matpower. The > baseimpdance was calculated by Basevoltage * Basevoltage / Base power > (MVA-Value) as written in my collection of formulas. > But the impedances of the branch were so small that there's almost no > powerloss and no decrease in the voltage between bus 1 & 2. > I tried to scale up my Lowvoltage problem by setting 100MW for (real) 100kW > and 230kV for 230V(real). But it didn't work. The modell didn't converge or > gave wrong values back. So I want to know whats the best way to modell my > Low-Voltage-problem in Matpower? > > > Somehow I did'nt found a good way decripted in the manual how to cope with > low voltage networks. > (Power ~ kW not MW and Voltage 230V) > > Can you help me?! Which settings have to be done to calculate a > low-voltage-network with matpower? > The concrete Data are: > 230 V (RMS) between phase and neutral Line, 3 phase-model (Star-circuit, > symmetric Loads and generations!) > Loadvalues somewhere between 2-100 kW at each bus (fix Load/ fix generation) > and a balancing generator representing the connected network to upper > Voltage-Network-Layers... > > I would be really happy, if you could give me some hints, ideas or tipps to > cope with that problem. > Thanks a lot! > > Yours sincerely, > Oliver Kopp > Germany > > > > > > > > > > ___________________________________________________________ > SMS schreiben mit WEB.DE FreeMail - einfach, schnell und > kostenguenstig. Jetzt gleich testen! http://f.web.de/?mc=021192 >
