• S.Abirami

Oscillations in control loops deviate the process output from desired operating value i.e. the setpoint. The presence of oscillations leads to reduced plant profitability and increased energy consumption. Oscillations in control loops may be due to various reasons. They are caused by external oscillatory disturbances, aggressive controller tuning and a very common cause for oscillations is due to nonlinearity (mostly stiction) in control valves. It is significant to detect valve stiction primarily, so that suitable action could be taken to get rid of this situation. In this paper, we mainly focus on stiction nonlinearity and to detect them using the Bispectrum and Bicoherence analysis for a highly nonlinear Shell and Tube Heat Exchanger (STHX) process

Oscillations, oscillating disturbances, aggressive controller tuning, valve stiction, Bispectrum, Bicoherence, STHX.

"Detection of Stiction using HOSA for a Shell and Tube Heat Exchanger Process", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 11, page no.21-26, November-2018, Available :http://www.jetir.org/papers/JETIR1811504.pdf

"Detection of Stiction using HOSA for a Shell and Tube Heat Exchanger Process", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 11, page no. pp21-26, November-2018, Available at : http://www.jetir.org/papers/JETIR1811504.pdf