Warianty tytułu
Programming in process control
Języki publikacji
Abstrakty
Celem artykułu jest pokazanie związków pomiędzy układami sterowania a narzędziami informatycznymi. Narzędzia informatyczne w energetyce mają zastosowanie przede wszystkim do identyfikacji obiektu, optymalizacji trajektorii sygnałów sterujących, tworzenia symulatorów, modelowania procesów, raportowania zdarzeń oraz analizowania trendów.
Development of computer languages such as Pascal, Delphi, C, Basic and others changed fundamentally quality and quantity of process control. Even early form of control - direct digital control - make it possibly to use different forms of control structures such as a state-space, Box-Jenkins models, model predictive control, neural networks and fuzzy logic. Programming adapts to changes in law which reflects cybernetic control of a government. Produced energy should have low emission of CO2, SOx, NOx. Models of boilers and control strategies computed from those models can lower emission and enables producers to emission trade. Some new technologies currently under development such as OxyFuel, CFB, biomass combustion with coal require new computer programs to control whole process. Ease to obtain and cheap feedback systems worsens quality indices in control loops. On the other hand feedforward systems require a lot of additional work to control process properly. System should be identified - both equation structure and parameters, next optimized by using e.g. dynamic programming principle, Pontryagin maximum principle or Euler-Lagrange equations. Optimization can concern real time or future signals acting on process. Main task are: minimizing estimate of a state, maximizing of probability of correct decision, minimizing time or energy needed to obtain goal and maximizing effect of strategy. Predictive control uses convolution, neural networks or Box-Jenkins models. Expert systems and analitycal systems can be combined in one control loop. Example is state-space model describing dynamic properties of a process in different cells of phase space and fuzzy rules describing gain coefficient changes of a linear controller between cells. Since 1969, when Yaskawa uses brusless motor and solid state electronic with programm instead of commutator, it is visible a trend on a market consisting in replacing mechanical parts by electronical parts and programms. In heat and power engineering there are pumps and fans with frequency converters. Future programs will be reflecting more accurately dynamics of a process to control it more exactly. Good example is heating network. Controllers used in central heating plants control few loops separately without optimization of whole heat delivered to customers. Effective use of programming in process control requires cooperation between process engineer, programmers, electronic engineer and scientist.
Słowa kluczowe
Czasopismo
Rocznik
Tom
Strony
26-32
Opis fizyczny
bibliogr. 10 poz., rys.
Twórcy
autor
- Politechnika Wrocławska, janusz.lichota@pwr.wroc.pl
Bibliografia
- [1] Astrom K.J.: Prezentacje do wykładu “Control system design”, University of California.
- [2] Dorf R.C.: Modern control systems. Addision-Wesley Publishing Company, 1989.
- [3] Korbicz J., Obuchowicz A., Uciński D.: Sztuczne sieci neuronowe. Akademicka Oficyna Wydawnicza, War¬szawa 1994.
- [4] Lichota J.: Test signals for NOx emission identification of coal boiler. Rynek Energii 2006, nr 6.
- [5] Marciniak M.: Współspalanie biomasy z wykorzystaniem technologii złoża fluidalnego. W: [Materiały] Mię¬dzynarodowa Konferencja Naukowo-Techniczna „Energetyka 2006”, Wrocław.
- [6] Niederliński A.: Systemy cyfrowe automatyki przemysłowej. WNT, Warszawa 1977.
- [7] Nowak W.: Ograniczenie emisji CO2. W: [Materiały] Międzynarodowa Konferencja Naukowo-Techniczna „Energetyka 2006”, Wrocław.
- [8] Rakowski J.: Automatyka cieplnych urządzeń siłowni. WNT, Warszawa 1976.
- [9] Stengel R.: prezentacje do wykładu „Robotics and intelligent systems”, Princeton University, 2005.
- [10] Wawrzyniak S.: Technologia CFB w kierunku zmniejszenia emisji CO2. W: [Materiały] Międzynarodowa Konferencja Naukowo-Techniczna „Energetyka 2006”, Wrocław.
Typ dokumentu
Bibliografia
Identyfikatory
Identyfikator YADDA
bwmeta1.element.baztech-article-BPL2-0010-0024