hi, sorry to bother you again but your advice is very useful and helpful! I have increased the reactive power at a bus and logged the data into Excel spreadsheet (attached). I was wondering if you could have a look at the voltage collapse curve and comment on the authenticity of it -if it's realistic or not - to me it seems to linear.
thanks so much, shane. Quoting David Vowles <[email protected]>: > The following comment is not really about Matpower but rather wind farm > modelling. > > A difficulty that can occur when modelling wind farms is that it is > common for the wind farm controllers to regulate the power factor at the > point of common coupling. Thus if, for example, the wind farm controls > the power factor to unity at the transmission system interface to the > wind farm there may be two levels of transformation between the > generator bus which represents the turbines in the wind farm and the HV > transmission system bus. Thus, it is necessary (in the case of DFIGs or > inverter connected turbines), to apriori estimate the reactive power > output of the turbines necessary for unity power factor at the point of > common coupling. In such cases it would be desirable for the loadflow > program to have facilities to allow a generator (or group of generators) > to regulate the power factor at a remote point. > > Cheers, > David. > > Genevieve Coath wrote: > > Hi, > > > > I have modelled wind farms in MATPOWER, and as Ray has suggested > > below, did use negative values for the active power injection of the > > wind farm (i.e. subtracted this from existing load at that bus), but a > > positive value of reactive power consumption (i.e. added this to the > > existing load Q demand at that bus) assuming that the wind farm > > comprises asynchronous wind turbine generators. Shunt reactances or > > susceptances can be entered as positive values in columns 5 and 6. > > > > Cheers, > > > > Genevieve > > > > On Mon, Mar 19, 2007 at 04:20:33PM -0400, Ray Zimmerman wrote: > > > >> On Mar 19, 2007, at 4:07 PM, [email protected] wrote: > >> > >> > >>> Quoting Ray Zimmerman <[email protected]>: > >>> > >>> > >>>> On Mar 18, 2007, at 8:11 PM, [email protected] wrote: > >>>> > >>>>> Wondering if it would be possible to model the integration of a > >>>>> wind farm of say > >>>>> 100MW using MATPOWER, thinking could enter the reactive power, is > >>>>> this possible? > >>>>> > >>>> If you are thinking of modeling it as a specified P and Q injection, > >>>> you can include these in the bus matrix as negative loads. > >>>> > >>>> Ray > >>>> > >>>> > >>> yes that was my initial plan. however is it possible to enter > >>> reactances and > >>> susceptance for that option? excuse my ignorance in this area. > >>> > >> I'm not sure I completely understand what you're trying to do, > >> but ... the constant power portion of a load is entered in cols 3 & 4 > >> of the bus matrix, and the constant impedance portion in cols 5 & 6. > >> And yes, they can be combined. > >> > >> For a wind farm (or other source of power) it may make sense to use > >> negative values in cols 3 & 4, but since I'm not familiar with the > >> models I don't know what makes sense for columns 5 & 6, though I > >> assume if you're using them at all they should be positive. > >> > >> Sorry I'm not more familiar with the models for wind, > >> > >> Ray > >> > > > -- > David Vowles, > Research Engineer, > School of Electrical and Electronic Engineering, > The University of Adelaide, > Australia, 5005. > > Phone: +61 8 8303 5416 > Fax: +61 8 8303 4360 > >
Voltage Collapse.xls
Description: MS-Excel spreadsheet
