many thanks Eng. Mahmoud abdallah Teaching Assistant Ain Shams University Faculty of Engineering
On Wednesday, February 19, 2014 4:05 PM, Ray Zimmerman <[email protected]> wrote: No. My point was simply that the power flow either sets the voltage and solves for the reactive power injection (PV bus) or sets the reactive power injection and solves for voltage (PQ bus). Using the ENFORCE_Q_LIMS option does not change this fact. It simply allows the program to decide for you how you want to model the bus, essentially saying it’s a PV bus unless that results in a Q limit violation, in which case it’s a PQ bus, with the Q injection set to the limit. -- Ray Zimmerman Senior Research Associate B30 Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On Feb 18, 2014, at 8:31 PM, Mahmoud Abdallah <[email protected]> wrote: thus >you mean I can't use Q limits to limit Q in a certain range and > if the limit violated the power flow will not be converted ?? >Eng. Mahmoud abdallah >Teaching Assistant >Ain Shams University >Faculty of Engineering > > > > >On Tuesday, February 18, 2014 12:08 PM, Ray Zimmerman <[email protected]> wrote: > >You cannot specify both reactive power and voltage. You must specify one and >solve for the other. The ENFORCE_Q_LIMS option that Shri mentions simply >indicates to the program that you want to change your mind about which one you >are specifying in the case where a reactive power limit will be violated by >specifying V. > > >-- >Ray Zimmerman >Senior Research Associate >B30 Warren Hall, Cornell University, Ithaca, NY 14853 >phone: (607) 255-9645 > > > > >On Feb 18, 2014, at 11:06 AM, Abhyankar, Shrirang G. <[email protected]> >wrote: > >By default, power flow does not enforce gen. reactive power limits. But you >can use the option ENFORCE_Q_LIMS from the mpoption options database to set >limits on the reactive power generation. Do help mpoption for more info. > > >Shri > > >From: Mahmoud Abdallah <[email protected]> >Reply-To: MATPOWER discussion forum <[email protected]> >Date: Tue, 18 Feb 2014 05:00:50 -0800 >To: MATPOWER discussion forum <[email protected]> >Subject: Re: ask in matpower > > > > >>dear sir >>I don't want specify reactive power >>I only want the change in reactive power should be negative value >> >> >>thus I try to put the limit of reactive power generated from bus 37 to be >>only negative for example >>from -4.4 to -4 >> >> >>but power flow not consider this limits >> >> >>what I can do to make the reactive power generated from bus 37 to be negative >>values >>(not fixed but change in a range of negative values ) >> >> >>thank you in advance >>Eng. Mahmoud abdallah >>Teaching Assistant >>Ain Shams University >>Faculty of Engineering >> >> >> >> >>On Friday, February 14, 2014 10:33 PM, Ray Zimmerman <[email protected]> wrote: >> >>The point of my previous post was that the power flow was doing what you told >>it to (assuming I was correct about you specifying it as a PV bus). If you >>want the power flow to solve for the voltage at the bus, given a specified >>reactive power injection (which is what you seem to be expecting), then you >>have to specify that by changing the BUS_TYPE to PQ in the input data. >> >> >> >> >> >> >>-- >>Ray Zimmerman >>Senior Research Associate >>B30 Warren Hall, Cornell University, Ithaca, NY 14853 >>phone: (607) 255-9645 >> >> >> >> >>On Feb 14, 2014, at 2:35 AM, Mahmoud Abdallah >><[email protected]> wrote: >> >> >>>dear sir >>> >>> >>>this bus has wind thus it can't produce reactive power >>> >>> >>>all reactive power comes from the network to bus 37 >>> >>> >>>thus the reactive power in the power flow output should be negative at bus >>>37 >>>Eng. Mahmoud abdallah >>>Teaching Assistant >>>Ain Shams University >>>Faculty of Engineering >>> >>> >>> >>> >>>On Friday, February 14, 2014 12:53 AM, Ray Zimmerman <[email protected]> >>>wrote: >>> >>>Presumably it is specified as a PV bus, which means that you are asking the >>>power flow program to solve for the reactive power required to maintain the >>>specified voltage magnitude. >>> >>> >>> Ray >>> >>> >>> >>> >>> >>> >>>-- >>>Ray Zimmerman >>>Senior Research Associate >>>B30 Warren Hall, Cornell University, Ithaca, NY 14853 >>>phone: (607) 255-9645 >>> >>> >>> >>> >>>On Feb 13, 2014, at 5:36 PM, Mahmoud Abdallah >>><[email protected]> wrote: >>> >>> >>>> dear sir >>>> >>>> >>>>I use case 39 which has wind at bus 37 >>>> >>>> >>>>the wind at bus 37 has positive active power and negative reactive power >>>> >>>> >>>>but when I use "runpf" with change in active power to be 1.5 * its old >>>>value >>>> >>>> >>>>I find that reactive power (of bus 37) in the result of power flow becomes >>>>positive ??? how >>>> >>>> >>>>Eng. Mahmoud abdallah >>>>Teaching Assistant >>>>Ain Shams University >>>>Faculty of Engineering >>>> >>> >>> >>> >> >> >> > > >
