Oven Temperature Control by Integral - Cycle Binary Rate Modulation Technique

  • Tipsuwanporn, V. (Faculty of Engineering, King Mongkut’s Institute of Technology Ladkrabang) ;
  • Piyarat, W. (Department of Electrical Engineering, Faculty of Engineering, Srinakharinwirot University) ;
  • Chochai, N. (Department of Electrical Engineering, Faculty of Engineering, Saint John’s University) ;
  • Jamjan, K. (Department of Electrical Engineering, Faculty of Engineering, Saint John’s University) ;
  • Paraken, Y. (Department of Electrical Engineering, Faculty of Engineering, Srinakharinwirot University)
  • Published : 1999.10.01

Abstract

This paper proposes controlling of temperature in an oven by using 4 bits Integral - Cycle Binary Rate Modulation (IBRM) method and ac line with frequency 50 Hz. Microcontroller MCS-51 controls IBRM according to Proportional Integral controller (PI) function. Discrete signals are used in the system modeled by using Ziegler Nichols principle for analyzing the stability before designing the system. This procedure makes it easy to investigate system response. The system is implemented by 4 bits digital circuit which gives 320 patterns of ac signal fur controlling the generation of energy for 3,000 watts thermal coil every 20 ms of each cycle. We divide scan time (Ts$\sub$n/) in to 20 intervals, 1 ms interval is selected to generate 16 patterns IBRM. Because of this method gives the ripple lower than 2% it generates less noise fur system. Moreover, we can consider whole system from the time model of control procedure and IBRM algorithm at 40-200$^{\circ}C$ with ${\pm}$ 1$^{\circ}C$ error in the 1 cubic meter oven.

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