Please check your case file again. You don't have any reference bus ( bus type = 3) in the bus struct.
Shri From: Marco Barbetta <marco.barbetta1...@gmail.com<mailto:marco.barbetta1...@gmail.com>> Reply-To: MATPOWER discussion forum <matpowe...@list.cornell.edu<mailto:matpowe...@list.cornell.edu>> Date: Mon, 24 Nov 2014 20:39:47 +0100 To: MATPOWER discussion forum <matpowe...@list.cornell.edu<mailto:matpowe...@list.cornell.edu>> Subject: Re: Represent generators as PQ buses However, i tried to set all buses as PQ and only one bus as REFERENCE, but i get this error: ??? Attempted to access pv(1); index out of bounds because numel(pv)=0. Error in ==> bustypes at 61 ref = pv(1); %% use the first PV bus Error in ==> runpf at 134 [ref, pv, pq] = bustypes(bus, gen); Can anyone explain this? As said in previous messages, i kept generators in the gen struct with their normal values (positive). Thanks, Marco Barbetta 2014-11-24 19:29 GMT+01:00 Marco Barbetta <marco.barbetta1...@gmail.com<mailto:marco.barbetta1...@gmail.com>>: Ok, while an eventual negative value for QG represents an absorbed reactive power, right? 2014-11-24 18:05 GMT+01:00 Abhyankar, Shrirang G. <abhy...@mcs.anl.gov<mailto:abhy...@mcs.anl.gov>>: Positive values for PG, QG in the gen struct represent power injected into the bus. Shri From: Marco Barbetta <marco.barbetta1...@gmail.com<mailto:marco.barbetta1...@gmail.com>> Reply-To: MATPOWER discussion forum <matpowe...@list.cornell.edu<mailto:matpowe...@list.cornell.edu>> Date: Mon, 24 Nov 2014 17:22:59 +0100 To: MATPOWER discussion forum <matpowe...@list.cornell.edu<mailto:matpowe...@list.cornell.edu>> Subject: Re: Represent generators as PQ buses Thank you for your clear answer: as you said, i set the 150/20 kV transformer as slack bus (because i need to know its P and Q, in order to look for any inversion of power towards HV network), and all other buses as PQ buses (because i need to know voltage magnitude after running the power flow). What about the values of PG and QG? Can i keep their "normal" positive values or i need to change their signs? Thank you again, Marco Barbetta 2014-11-24 17:12 GMT+01:00 Abhyankar, Shrirang G. <abhy...@mcs.anl.gov<mailto:abhy...@mcs.anl.gov>>: Marco, MATPOWER does not have any in-built rule that changes the status of a bus from PQ to PV if a generator is incident on it. If you have a generator declared in the GEN struct with its bus type set to PQ in the BUS struct, then the bus voltage magnitude and angle are the variables for the power flow solution. For a PV bus, the voltage magnitude is held constant and the angle is the variable. You need to have atleast one reference bus in your system. If there is no slack bus, MATPOWER uses the first bus declared with type PV as the reference. Shri From: Marco Barbetta <marco.barbetta1...@gmail.com<mailto:marco.barbetta1...@gmail.com>> Reply-To: MATPOWER discussion forum <matpowe...@list.cornell.edu<mailto:matpowe...@list.cornell.edu>> Date: Sat, 22 Nov 2014 18:50:30 +0100 To: <MATPOWER-L@cornell.edu<mailto:MATPOWER-L@cornell.edu>> Subject: Represent generators as PQ buses Dear collegues, starting from this discussion (https://www.mail-archive.com/matpower-l@cornell.edu/msg03439.html) i see that is possible to represent generators as PQ buses. As Simone said in previous discussion, this is requested in order to analyze the network's voltage profile, letting voltage magnitude imposed only in the slack bus and free to change in all other buses. My question is: if i put in the GEN struct all generators with their PG and QG, in the BUS struct all loads with their PD and QD and i impose bus type = 1 (PQ) for ALL buses, will MatPower have any problem? In this way, wil the voltage magnitude for all buses be let free to change, in order to be analyzed post-simulation? I don't understand if the generator buses automatically become PV buses only for the fact to be set in the GEN struct, or if "rules" the condition set in the BUS struct. Another question: in this concept, PG and QG can remain positive or have to be set with negative values? Thanks to all. Best regards, Marco Barbetta
