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: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.Quoting Ray Zimmerman <[email protected]>:yes that was my initial plan. however is it possible to enter reactances andOn 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. Raysusceptance for that option? excuse my ignorance in this area.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
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