Lončar, Dražen (2001) Primjena neizrazite logike u regulacijskom sustavu termoenergetskog bloka. = Fuzzy logic application in thermal power plant control system. Doctoral thesis , Sveučilište u Zagrebu, Fakultet strojarstva i brodogradnje, UNSPECIFIED. Mentor: Šerman, Nikola.
Full text not available from this repository.Abstract (Croatian)
U radu je istražena mogućnost primjene neizrazite logike na svim razinama sustava regulacije i vođenja termoenergetskog bloka. Istraživanja su provedena usporedbom djelovanja neizrazitih i odabranih konvencionalnih regulacijskih koncepata simulacijom modela termohidrauličkih procesa u odabranom, ugljenom loženom termoenergetskom bloku snage 210 MW. Izloženi su i primjerima ilustrirani temeljni pojmovi neizrazite logike, pokazana je ekvivalentnost postupaka lokalnog i globalnog neizrazitog zaključivanja i opisane su razlike između najčešće primjenjivanih neizrazitih modela. Ilustriran je nelinearni karakter izlazne funkcije neizrazitog modela, te analiziran utjecaj raspodjele funkcija pripadnosti i izbora operatora kompozicije na njen oblik. Pokazano je da neizraziti model na lokalnoj razini predstavlja nelinearno proširenje konvencionalnih regulatora PID djelovanja. Opisana je primjena neizrazitih modela na visim regulacijskim razinama, u kojima se neizraziti modeli koriste u ulozi nadređenih multivarijabilnih struktura koje propisuju djelovanje podređenih sustava iii služe za adaptaciju i optimiranje parametara lokalnih regulatora. Izveden je nelinearni matematički model dinamike termohidrauličkih procesa u protočnom generatoru pare, te razvijena nova verzija programa za njegovu simulaciju. Funkcionalnost modela i algoritma njegova rješavanja provjereni su na primjeru isparivačke cijevi eksperimentalnog uređaja usporedbom rezultata simulacije propagacije krize kipljenja s rezultatima mjerenja. Simulacijom matematičkog modela promatranog termoenergetskog bloka u uvjetima karakterističnih pogonskih poremećaja reproducirane su glavne dinamičke značajke istraživanog objekta. Simulacijama nelinearnog matematičkog modela tehnološkog procesa i njegovih interakcija s glavnim regulacijskim podsustavima pokazano je da je primjena koncepta neizrazite logike u sustavu vođenja i regulacije termoenergetskog bloka u načelu moguća. Isto tako učinci njene primjene u nekim segmentima sustava, naročito u podsustavu regulacije temperature pare, usporedivi su pa čak i bolji od referentnog konvencionalnog koncepta. Razvijen je vlastiti koncept neizrazitog tropoložajnog regulatora koji u usporedbi s uobičajenim rješenjima osigurava jednako kvalitetno djelovanje regulacijskog sustava, ali sa značajno manjim brojem prorada elektromotornog pogona izvrsnog organa.
Abstract
Potential and possibilities for application of fuzzy logic at different levels of thermal power plant control system by comparing it with the typical conventional control algorithms are investigated in the thesis. The performance of the chosen control concepts is evaluated by simulation of the process dynamics model of the 210 MW coal fired unit. The basics of fuzzy set theory are presented and illustrated by examples. The two most frequently used fuzzy models are described. The equivalency between the local and the global inference procedure is shown. An analysis of fuzzy models with respect to the different parameters is provided. Various ways of fuzzy logic implementation in control systems were considered. Fuzzy models, when applied in direct control at the lower levels, dominantly serve as non-linear extension of the conventional linear controllers. At the higher control levels fuzzy models are mainly used either as a replacement of the experienced operator in control of the complex processes, or for the parameters adaptation and the tuning of the subordinated controllers. An improved version of computer package for modeling and simulation of the thermohydraulic process dynamics in the once through steam generator tube system was developed. The model and solver functionality was proven by the similarity of the simulation results with the measurements of the tube wall burnout temperature conditions in an experimental small scale evaporator tube. The dynamic characteristics of the chosen thermal power plant were illustrated by the simulations of the open loop responses to the typical operating disturbances. The results obtained by the simulation of the non-linear mathematical model of the thermohydraulic processes and its interactions with the main control subsystems confirm that the usage of the fuzzy logic in the power plant control system is possible. The performance of the fuzzy algorithms is fully comparable to the conventional concepts at all levels of the control system, while in the steam, temperature control fuzzy performs better than the referent conventional algorithms. The proposed fuzzy three-point controller achieves the same performance as the conventional algorithm with considerably smaller number of actuators electromotive drive activations.
| Item Type: | Thesis (Doctoral thesis) |
|---|---|
| Uncontrolled Keywords: | termoenergetski blok; regulacija procesa; neizrazita logika; tropoložajni regulator |
| Keywords (Croatian): | thermal power plant; fuzzy logic; three-point controller |
| Divisions: | 500 Department of Energy, Power Engineering and Environment > 510 Power Engineering and Energy Management Chair |
| Date Deposited: | 22 Sep 2014 18:00 |
| Last Modified: | 16 Oct 2015 13:19 |
| URI: | http://repozitorij.fsb.hr/id/eprint/159 |
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