Hi Gokturk, Yes, the tap settings are static variables. They do however require adjustment during the load-flow calculation (just in the same way that a generator reactive power output is varied in each iteration of the N-R method in order to maintain its given voltage). Please refer to the literature if this is unclear. For example:
Peterson, N.M.; Meyer, W.S., "Automatic Adjustment of Transformer and Phase-Shifter Taps in the Newton Power Flow," Power Apparatus and Systems, IEEE Transactions on , vol.PAS-90, no.1, pp.103,108, Jan. 1971 My question is more the following – Is it possible to pause the matpower load flow function ‘runpf()’ after each iteration of the N-R method? Regards, Dom Von: [email protected] [mailto:[email protected]] Im Auftrag von Göktürk Poyrazoglu Gesendet: Mittwoch, 4. Juni 2014 14:49 An: MATPOWER discussion forum Betreff: Re: Automated Tap-Changing in Load Flow Calculation Hi Dom, I totally believe you have a good reason to change the tap settings in each iteration, but I couldn't get it. 'runpf' command solves a set of power flow equations. The state of the system is instantaneous, not time variant. Tap settings of a transformer is also a static variable. You will set the value as a parameter (not a variable), then you will solve the equations. If you start to change the tap settings in each iteration, most probably, the algorithm will never converge and stop. And there is no physical meaning of changing the tap settings in each iteration. Please correct me if I am wrong. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Gokturk Poyrazoglu Teaching Assistant | Student Assistant Department of Electrical Engineering / The State University of New York at Buffalo 230V Davis Hall, Buffalo, NY 14260 Phone : (716) 239 - 8095 E-mail : [email protected]<mailto:[email protected]> On Wed, Jun 4, 2014 at 6:17 AM, Hewes, Dominic <[email protected]<mailto:[email protected]>> wrote: Hi, Regarding the inclusion of auto tap-changers for transformer branches, it has been recommended in previous posts that the tap setting for each transformer branch can be updated after each iteration of the Newton-Raphson procedure. Using the conventional ‘runpf’ command, is it possible to pause the N-R function after each iteration rather than running until the solution is found? After each ‘pause’, I would like to calculate new tap settings and then run the next iteration – but I am not sure if this ‘pause’ can be implemented with the conventional ‘runpf’command? Any help/advice would be very much appreciated. Regards, Dom
