Effect of Tuning Parameter on the Stability of the TDF-IMC Scheme for Load Frequency Control

Abstract

Effect of tuning parameter on the stability of the TDF-IMC for load frequency control is studied. Choice of an optimal value is found to be directly affecting the feedback filter $(\mathbf{Q}_{\mathbf{d}})$ and depends on the nature of model order reduction scheme used (such as Padé approximation, Routh and SOPDT). The findings corroborate with our previously published results, that the bi-parametric variation in $(\mathbf{T}_{\mathbf{g}}-\mathbf{T}_{\mathbf{t}})$ can be effectively mitigated by preferring SOPDT in comparison to Pade and Routh for an optimal tuning parameter. Further, the response to disturbance is quick and damps swiftly with low amplitude oscillations. In conclusion, we identify that the SOPDT offers better performance at optimal tuning parameter (depending on the design preference for the gain and phase margin).